|
The smallest living units capable of carrying out their own basic life functions are called |
Cells |
|
Cells are classified into which of the following four broad categories? |
Neurons, muscle, epithelial, and connective tissue |
|
Epithelial cells are associated with a noncellular material called a |
Basement membrane |
|
_____ are found in the linings of hollow organs where they separate fluids in the interior cavity from the surrounding body fluids. The interior cavity of a hollow organ or vessel is known as a ______ |
Epithelial : lumen |
|
The tissue type that generates mechanical force and movement, and whose activity is controlled both on a voluntary and involuntary level, is _____ tissue |
Muscle |
|
Glands are derived from what type of tissue? |
Epithelial |
|
The cell types blood, bone, fat, and lymph would be categorized into which of the following major cell classes? |
Connective tissue cells |
|
Which tissue type includes cells contained in an extracellular matrix composed of collagen and elastin? |
Connective tissue |
|
What is a general name for the noncellular material that holds the widely scattered cells of connective tissue together? |
Extracellular matrix |
|
Which of the following is a protein found in connective tissue that provides the tensile strength to resist stretching? |
Collagen |
|
What are the structures that attach bone to muscle? |
Tendons |
|
Organs of the body are defined as |
A combination of two or more tissues that make up a structure which performs a specific function |
|
Which of the following accurately represents the order of complexity for the components of the body, from least to most complex? |
Cells, tissues, organs, organ systems |
|
The uptake of nutrients across the epithelial cells of the gastrointestinal tract and into the bloodstream is called |
Absorption |
|
What organ system includes the pituitary gland, adrenal gland, and thyroid gland? |
Endocrine |
|
The lumen of which of the following systems is part of the internal environment? |
Cardiovascular system |
|
The process whereby fluid from the bloodstream enters the tubules of the kidneys is called |
Filtration |
|
The process whereby fluid in the kidneys is transported from the tubules back into the bloodstream is called |
Reabsorption |
|
Referring to a membrane as "selectively permeable" describes its ability to |
Allow the movement of particular molecules across a membrane |
|
Extracellular fluid is composed of |
Interstitial fluid and plasma |
|
Total body water is composed of |
Intracellular and extracellular fluid |
|
Where is most of our total body water located? |
Inside cells |
|
Which of the following compartments contain most of the water found in the human body? |
Intracellular fluid |
|
What are the two extracellular fluid compartments of the body? |
Interstitial fluid and plasma |
|
The portion of body water outside of cells that bathes most cells of the body is called |
Interstitial fluid |
|
The fluid compartment with a high sodium and protein concentration is called |
Plasma |
|
Which of the following best describes intracellular fluid? |
Rich in proteins and potassium |
|
The fluid compartment with a high sodium concentration that contains only trace amounts of protein is called |
Interstitial fluid |
|
For a person weighing 150 pounds, how many liters of water are contained in all of the body’s compartments? |
42 |
|
Homeostasis is a term which describes the process whereby the body |
Maintains a constant internal environment |
|
Of the following conditions associated with excess heat, which is the most serious condition? |
Heat stroke |
|
The maintenance of a stable internal environment compatible for life is called |
Homeostasis |
|
What is the primary mechanism for maintaining homeostasis? |
Negative feedback |
|
Which of the following statements about homeostasis is FALSE |
The primary mechanism to maintain homeostasis is positive feedback |
|
Changes in the external environment alter the ____, which is detected by the ____, and that information is sent to the integrator |
Regulated variable : sensor |
|
Lisinopril is a medication that lowers high blood pressure back to within a desired range of function. The action of this medication is similar to that of a ______ in the human body |
Negative feedback response |
|
If you were to take the temperature of everyone in class, assuming no one is sick, you would find that not everyone has a temperature of 98.6F. Which statement best explains your findings? |
Most regulated variables, such as temperature, fluctuate continuously and oscillate about the set point due to negative feedback control. |
|
When people cut themselves, they have clotting factors in their blood that will be released continuously in a cascade until their blood clots and terminates the bleeding. What mechanism caused their blood to clot? |
Positive feedback control |
|
A ___ detects a change in a regulated variable and sends that information to a ___ which relayed signals to a ____, usually a muscle or a gland |
Sensor : integrating center : effector |
|
Vinnie has high blood glucose and must take insulin shots to control his blood sugar. Why must he override his normal homeostatic mechanisms by taking medication? |
Vinnie’s negative feedback controls are not functioning properly |
|
A patient has a high salt or sodium intake which draws fluid out of his cells to dilute the sodium. This process occurs as a result of |
Negative feedback control |
|
The process of maintaining the internal environment in a state compatible for life is called ___, and it occurs primarily through |
intrinsic control : homeostasis |
|
Which of the following is an example of negative feedback? |
If blood pressure increases above normal, baroreceptors in major arteries detect the change and send signals. Certain areas of the brain then send signals to the nerves that control the heart and blood vessels to make the heart beat slower and the blood vessels increase in diameter, which in turn reduce the blood pressure. |
|
Luteinizing hormone – mediated regulation of estrogen during ovulation in women is an example of |
A positive feedback loop |
|
The feedback loop involving luteinizing hormone and estrogen is terminated by |
Ovulation, which decreases estrogen secretion |
|
Which of the following is a normal blood glucose level? |
100 mg/dL |
|
What is the difference between diabetes mellitus and diabetes insipidus |
One is a lack of ADH secretion; the other is a resistance to ADH |
|
What cells secrete insulin? |
Beta cells of the pancreas |
|
Approximately what percentage of people living in the US suffers from diabetes mellitus? |
8% |
|
Which of the following people would be more prone to develop diabetes mellitus type II? |
An obese Hispanic adult |
|
What percentage of adults in the United States is obese? |
35% |
|
Which of the following types of diabetes mellitus was formerly referred to as insulin-dependent or juvenile-onset diabetes mellitus? |
Type 1 |
|
What are the two major consequences for those who suffer from diabetes mellitus? |
High blood glucose and cells that cannot utilize that glucose for energy |
|
Although diabetes mellitus has many symptoms, the primary diagnostic symptoms of the disease are __ and __ |
Elevated blood glucose : glucose in the urine |
|
What lab test, often deemed the "lie detector test" by health care workers, measures the average blood glucose levels for the past 2-3 months |
Hemoglobin A1c test |
|
Obesity is identified using what measurement? |
Body mass index (BMI) |
|
What percentage of women will develop type 2 diabetes after developing gestational diabetes? |
5-10% |
|
What is the primary reason the prevalence of diabetes is increasing in the US population? |
An aging population |
|
Pre diabetics have a fasting blood glucose level of ___ and according to the Centers for Disease Control (CDC) approximately __ million Americans are pre diabetic. |
100-125 mg/dL : 80 |
|
John has type 2 diabetes. He has a sedentary lifestyle, is overweight, and recently went to the doctor who gave him a hemoglobin A 1C test which came back at 7%. What is the best course of treatment for John? |
A strict diet, frequent monitoring of his blood glucose, exercise, and oral glucose medication |
|
Which tissue below is specialized for lining the lumen of vessels material? |
Epithelial tissue |
|
Which tissue below conducts signals primarily via electrical impulses? |
Nervous tissue |
|
Which tissue below provides structural support? |
Connective tissue |
|
Which tissue below contracts to generate force? |
Muscle tissue |
|
The elimination of unabsorbed materials from the body refers to which of the following processes below? |
Excretion |
|
Movement from the lumen of the gastrointestinal tract to the blood would represent which of the following processes? |
Absorption |
|
Movement from the blood into the kidney tubules would represent which of the following processes? |
Filtration |
|
Which of the following is-are associated with the endocrine system? |
Adrenal gland |
|
Which of the following is/are associated with the nervous system? |
Brain |
|
Which of the following is/are a component of the cardiovascular system? |
Blood vessels |
|
Which of the following is/are associated with the respiratory system? |
Bronchi |
|
Which of the following is/are associated with the gastrointestinal system? |
Esophagus |
|
The smallest living units, capable of carrying out their own basic life processes, are |
Cells |
|
Cells that carry oxygen in the bloodstream are called |
Erythrocytes |
|
What tissue is specialized for separating fluids? |
Epithelial |
|
What tissue is a major component of bone, ligaments, and blood? |
Connective |
|
What tissue is specialized for generating electrical signals? |
Nervous |
|
What tissue is specialized to contract? |
Muscle |
|
The specific structures that attach bone to bone are called |
Ligaments |
|
The __ is the interior compartment of a hollow organ or vessel |
Lumen |
|
The process whereby enzymes are moved into the gastrointestinal tract to digest nutrients is called |
Secretion |
|
The process whereby fluid and ions that have not been reabsorbed by the kidneys exit the body as urine is called |
Excretion |
|
The fluid (non-cellular) portion of blood is called |
Plasma |
|
The fluid compartment with a high protein and potassium concentration is called |
Intracellular fluid |
|
Where is most of the water in the body found? |
In the intracellular fluid |
|
Insulin is a hormone that regulates blood glucose levels. It is released when glucose levels increase above normal. Based on the concepts of negative feedback, what effect will insulin have on blood glucose levels? |
It will decrease them |
|
Body mass index is a measure of weight in kilograms relative to |
Height in meters (squared) |
|
What type of ductless gland secretes hormones into the bloodstream? |
Endocrine |
|
Which statement below best defines homeostasis? |
Homeostasis is the process whereby the body maintains the internal environment in a state compatible for life |
|
Which statement below lists the essential components of a feedback loop and describes their function? |
Sensor detects a regulated variable; set point is the value of the regulated variable; integrator interprets the information and sends it to the appropriate effector; effector alters the regulated variable |
|
Physiology is the study of function and come in many forms, including plant physiology |
True |
|
Pathophysiology is what happens when normal body functions are disrupted |
True |
|
Connective tissue forms both endocrine and exocrine glands |
False |
|
Exocrine glands secrete hormones |
False |
|
The immune system protects the body from invading microorganisms |
True |
|
Most of the cells of the body are able to directly exchange materials with the external environment |
False |
|
The internal and external environments are separated by the selectively permeable membranes of epithelial cells |
True |
|
The most abundant substance in the body is carbon |
False |
|
Intracellular fluid and extracellular fluid are of the same ion composition |
False |
|
The homeostatic mechanisms of the body are unlimited in their ability to respond to changes in the external environment |
False |
|
Blood glucose is a regulated variable |
True |
|
Effectors bring about a final response in a negative feedback loop |
True |
|
Positive feedback loops are impossible to stop once they have begun |
False |
|
All forms of diabetes involve a decrease in plasma levels of insulin |
False |
|
Diabetes mellitus requires insulin injections for maintenance |
False |
|
Once a woman develops gestational diabetes, she will have diabetes for life |
False |
|
People with a body mass index less than 25 are most prone to develop type 2 diabetes mellitus |
False |
|
Cases of diabetes mellitus are increasing throughout the world, not just in the United States |
True |
|
Obesity predisposes a person to develop type 1 diabetes mellitus |
False |
|
Diabetes mellitus causes hyperglycemia |
True |
|
Which of the following nucleotide sequences accurately reflects the mRNA that would be produced from the double-stranded DNA showing in Figure? |
5’UGUCUCACUGUCUUG3′ |
|
Based upon a sequence of 15 nucleotides in a strand of DNA, what is the max amount of amino acids produced? |
5 |
|
What interaction between complementary bases holds the two strands of a DNA molecule together? |
Hydrogen bonds |
|
What interaction between the phosphate and the carbohydrate of a nucleotide holds the backbone of a DNA strand together? |
Covalent bonds |
|
Which of the following is NOT a monosaccharide? |
Lactose |
|
What type of molecule is shown in Figure 2.2 |
Disaccharide |
|
The presence of __ chemical groups makes carbohydrates __ |
Hydroxyl : polar |
|
Which of the following molecules is a disaccharide? |
Lactose |
|
Which of the following correctly describes glycogen? |
It is an important storage polysaccharide found in animal tissues |
|
Which of the following is an example of a pentose sugar? |
deoxyribose |
|
____ is a polysaccharide found in animal cells, whereas ___ is a polysaccharide found in plants that can be degraded by humans |
Glycogen : starch |
|
Which of the following molecules will dissolve readily in water? |
NaCl |
|
Which of the following statements concerning hydrogen bonds is FALSE |
They are strong attractive forces between hydrogen atoms and negatively charged atoms |
|
____ are molecules that contain primarily carbons and hydrogens linked together by non polar covalent bonds |
Lipids |
|
___ are molecules composed of a glycerol and three fatty acids |
Triglycerides |
|
A fatty acid that contains three double bonds in its carbon chain is said to be |
Polyunsaturated |
|
___ are molecules that form the bilayer of cell membranes and micelles |
Phospholipids |
|
The amphipathic property of phospholipids can be described as a |
Polar region that dissolves in water and a non polar region that repels water |
|
___ are modified fatty acids that function in intercellular communication and include prostaglandins and thromboxanes |
Eicosanoids |
|
____ acts as the precursor to steroid molecules, many of which function as hormones |
Cholesterol |
|
Based on the Figure above, what type of molecule is this? |
Steroid |
|
____ are molecules whose general structure includes a central carbon with a carboxyl group, an amine group, a hydrogen molecule, and a residual (R) group |
Amino acids |
|
Alpha-helixes and beta-pleated sheets are examples of ____ structures of a protein |
Secondary |
|
Formation of peptide bonds occurs by condensation reactions between the ___ group of one amino acid and the ____ group of another |
Carboxyl : amino acid |
|
The most common elements found in biomolecules are carbon, hydrogen, nitrogen, and |
Oxygen |
|
Each amino acid differs from others only by the |
Characteristic of its R group |
|
Hydrogen bonding between the amino hydrogen of one amino acid and the carboxyl oxygen of another is responsible for which of the following |
Secondary protein structure |
|
An acid is a molecule that acts as a |
Proton donor |
|
Ketoacids (a carboxylic acid group attached to a ketone) are often produced during fasting and uncontrolled diabetes mellitus. What potential outcome of this would be of greatest concern? |
Ketoacidosis |
|
The ___ structure of a protein is formed between residual (R) groups of the amino acid backbone by a number of different chemical interactions, dependent upon the nature of the residual groups interacting |
Tertiary |
|
Which of the following is an example of a fibrous protein? |
Collagen |
|
____ are molecules that are composed of one or more phosphate groups, a 5 carbon sugar, and a nitrogenous base |
Nucleotides |
|
Why are nucleotides (and their polymers) called nucleic acids when they contain nitrogenous bases? |
Phosphoric acid groups (becoming phosphates) are much stronger than nitrogen acts as a base |
|
When the body needs to make the elcosanoid thromboxane for wound repair, what component of the plasma membrane does it use for their synthesis? |
Fatty acid from phospholipid |
|
Which of the following is/are found in DNA but not RNA |
Both thymine and deoxyribose |
|
All of the following are basic components of proteins EXCEPT |
Potassium |
|
Which of the following molecule types is NOT a polymer? |
Fatty acid |
|
Which of the following is NOT a base in RNA |
Thymine |
|
Which of the following descriptions of a polymer is FALSE |
ATP is a polymer of phosphates |
|
Which of the following is NOT a function of nucleotides? |
Providing substrates for the citric acid cycle |
|
In eukaryotes, which of the following properties is TRUE for both DNA and RNA |
Follow the law of complementary base pairing |
|
____ is composed of a nucleotide, where the phosphate is bound to two spots on the ribose sugar |
cAMP |
|
The presence of ____ in the plasma membrane can inhibit crystallization |
Cholesterol |
|
Which of the following is NOT found in plasma membranes? |
Chromatin |
|
Which of the following components of the plasma membrane forms ion channels? |
Transmembrane proteins |
|
Which of the following is NOT an integral membrane protein? |
Actin |
|
Which of the following is an amphipathic molecule? |
Integral membrane protein |
|
Which of the following is NOT an amphipathic molecule? |
Glucose |
|
What is the layer of carbohydrates on the external surface of a cell called? |
Glycocalyx |
|
The _____ is the site of ribosomal RNA production |
Nucleolus |
|
Where is the genetic code stored? |
Nucleus |
|
Where inside a cell is glycogen stored? |
Cytosol |
|
Lipophobic molecules that are to be released by cells are stored in membrane-bound structures called |
Secretory vesicles |
|
Continuous with the outer portion of the nuclear pore, what membrane-bound structure functions in the synthesis of secretory proteins, integral membrane proteins, or proteins bound for other organelles? |
Rough endoplasmic reticulum |
|
The ___ is the site where lipids, triglycerides, and steroids are synthesized, as well as where calcium is stored within the cell. |
Smooth endoplasmic reticulum |
|
What is the site where steroids are stored in the cell? |
Steroids are lipid and will slide right through membranes; they cannot be stored in the cell. |
|
What organelle packages and directs proteins to their proper destination? |
Golgi apparatus |
|
Which of the following is NOT a property of smooth endoplasmic reticulum? |
Stores steroid hormones |
|
Hydrolytic reactions are when |
Two molecules are joined together by adding a water molecule |
|
Which of the following descriptions of the function of the organelle is FALSE |
Breakdown of phagocytosed bacteria occurs in the peroxisomes |
|
Detoxifying enzymes may be localized in what organelle? |
Peroxisomes |
|
In Tay-Sachs Disease, which organelle contains the impaired enzymes? |
Lysosome |
|
What organelle synthesizes most of the ATP used by cells? |
Mitochondria |
|
____ are membrane-bound organelles containing enzymes that degrade cellular and extracellular debris. |
Lysosomes |
|
____ are membrane-bound organelles that contain enzymes like catalase, which catalyzes the breakdown of h2o2 to h2o and o2 |
Peroxisomes |
|
Which of the following characteristics concerning ribosomes is FALSE |
Can be located in the Golgi apparatus |
|
Which of the following organelles contains its own DNA |
Mitochondria |
|
Which of the following is NOT a function of the cytoskeleton |
Cellular catabolism |
|
Which cytoskeletal proteins provide the structural support for microvilli? |
Microfilaments |
|
Keratin is an example of which type of cytoskeletal protein? |
Intermediate filaments |
|
Which of the following filaments is found in cilia and flagella? |
Microtubules only |
|
Which microtubular proteins are responsible for the distribution of chromosomes during cell division? |
Spindle fibers |
|
The protein ___ is responsible for generating force as micro tubular proteins in cilia slide past one another |
Dynein |
|
____ are proteins that fuse adjacent cells together to form a nearly impermeable barrier |
Occludins |
|
___ are proteins attached to intermediate filaments in regions where cells are exposed to mechanical stresses |
Cadherins |
|
____ are proteins that form channels between cells, allowing ions and small molecules to diffuse directly from one cell to the other |
Connexins |
|
In some cases, signals originating within one cell can diffuse directly to a neighboring cell through |
Gap junctions |
|
In the digestive tract, absorption is controlled by mechanisms on the cell’s apical membrane surface. What type of physical barriers would be in place to keep these mechanisms from being circumnavigated? |
Tight junctions |
|
Intercellular communication can occur through the binding of a chemical released from one cell to a specific _____ on another cell |
Receptor |
|
Which of the following does NOT describe a part of post-transcriptional processing? |
Formation of bonds between a phosphate group and a sugar |
|
The process whereby a complementary mRNA is produced from a DNA template is called |
Transcription |
|
During translation, ____ is synthesized in the _____ |
Protein : cytoplasm |
|
Based upon the triplet nature of a codon and the presence of four possible bases, how many possible amino acids might be coded for by mRNA? |
64 |
|
The initiator codon is composed of the sequence |
AUG |
|
The initiator codon, that originates translation, codes for the amino acid |
Methionine |
|
What strand of mRNA would be transcribed from the following strand of DNA: 5’AATG? |
3’UUAC |
|
Which of the following statements about the genetic code is TRUE? |
Termination codons do not code for amino acids |
|
The strand of DNA that gets transcribed to mRNA is called the |
Template strand |
|
According to the law of complementary base pairing, which of the following would be expected in any strand of DNA? |
A + G = C + T |
|
During transcription, |
RNA is synthesized from DNA in the nucleus |
|
What is the portion of DNA that codes for a particular protein? |
Gene |
|
If guanine makes up 29% of the nucleotides in a sample of DNA, what percentage of the sample would be adenine? |
21 |
|
What causes DNA to uncoil during transcription? |
Binding of RNA polymerase to the promoter sequence |
|
An anticodon is |
A three-nucleotide series on tRNA that is complementary to the mRNA to which it binds |
|
Which of the following statements about the genetic code is FALSE |
Each amino acid is coded for by only one codon |
|
Where does RNA polymerase bind to initiate transcription |
Promoter sequence |
|
The codon is |
mRNA language coding for a particular amino acid |
|
The promoter sequence of the gene is recognized by ____, which initiates transcription. |
RNA polymerase |
|
What is the base sequence of the tRNA molecule that recognizes the complementary mRNA molecule? |
Anticodon |
|
What is the correct order for the following list of steps for initiating translation? |
1. Binding of small ribosomal subunit to mRNA 2. Binding of initiator tRNA to mRNA 3. Binding of large ribosomal subunit to mRNA 4. Binding of a 2nd tRNA with its amino acid to the A site 5. Formation of covalent bond between methionine and second amino acid |
|
What happens at the P site of a ribosome? |
It holds the tRNA with the most recent amino acid that has been added to the polypeptide chain |
|
Post-transcriptional processing adds a ____ to the 5′ end of the mRNA molecule |
Cap |
|
Post-transcriptional processing adds a ___ to the 3′ end of the mRNA molecule |
Poly A tail |
|
Which of the following is NOT a function of the initiation factors associated with translation of protein from mRNA? |
They align the first tRNA with the A site on a ribosome |
|
The leader sequence of any protein that has just been translated functions to |
Determine the destination of the protein |
|
Which of the following processes is NOT a post-translational modification that occurs in the endoplasmic reticulum or Golgi apparatus to make proteins functional? |
The addition of more amino acids |
|
What is the outcome of having only the head of the sperm entering the oocyte? |
Mitochondrial DNA is only of maternal inheritance. |
|
Which of the following is NOT a possible destination for proteins that are completely synthesized on ribosomes free in the cytosol? |
Secreted from the cell |
|
When proteins are synthesized by ribosomes on the rough endoplasmic reticulum, where does the translation begin? |
Cytosol |
|
Which of the following are NOT embedded in the lipid bilayer at all? |
Peripheral proteins |
|
Where is the leader sequence of preproinsulin removed? |
Lumen of rough endoplasmic reticulum |
|
Ubiquitin tags proteins for what purpose? |
To mark for degredation by proteasomes |
|
What enzyme catalyzes the reaction whereby nucleotides are added to the polynucleotide chain during replication? |
DNA polymerase |
|
Aspirin and ibuprofen both block the enzyme cyclooxyrgenase from changing arachidonic acid, found in the phospholipid bilayer, into what? |
Prostaglandins |
|
During replication, which strand of the new DNA is synthesized from the 5′ to 3′ strand of original DNA |
Lagging strand |
|
Okazaki fragments are |
Small sections of newly formed DNA, built on the lagging (5′ to 3′) template strand |
|
During what phase of the cell cycle is the cell carrying out its normal activity and NOT involved directly in cell division? |
G 0 |
|
During what phase of the cell cycle does cellular replication of DNA occur? |
S |
|
During what phase of the cell cycle does rapid protein synthesis occur as the cell grows to double its size? |
G2 |
|
Which of the following is NOT a phase of mitosis? |
Meiosis |
|
During what phase of cell division do chromosomes align along the midline? |
Metaphase |
|
During what phase of cell division do two new nuclear envelopes begin to redevelop? |
Telophase |
|
What links sister chromatids together? |
Centromeres |
|
What is the correct level of structure for proteins containing more than one polypeptide chain? |
Quaternary |
|
What is the level of structure that corresponds to the sequence and number of amino acids in the polypeptide chain? |
Primary |
|
What is the level of structure that corresponds to the chemical interactions between R groups within the same polypeptide chain? |
Tertiary |
|
What level of structure is caused when the hydrogen bonds between the amino hydrogen of one amino acid and the carboxyl oxygen of another amino acid is formed? |
Secondary |
|
The junctions created by intermediate filaments which penetrate the membrane between two cells at the site of protein plaques, thereby forming strong linkage between the two cells, are also known as |
Desmosomes |
|
What junctions are found in epithelial tissue where they prevent paracellular movement of molecules? |
Tight junctions |
|
What junctions allow the passage of small molecules and ions from the cytosol of one cell to that of a neighboring cell? |
Gap junctions |
|
Which of the following packages proteins into secretory vesicles? |
Golgi apparatus |
|
Which of the following packages proteins into transport vesicles? |
Smooth ER |
|
The enzyme catalase is located where? |
Peroxisomes |
|
Endocytotic vesicles fuse with what organelle? |
Lysosomes |
|
The bulk of ATP production is performed where? |
Mitochondria |
|
Lipids synthesis is performed where? |
Mitochondria |
|
Which cellular protein is found in gap junctions? |
Connexons |
|
Which cellular protein is found in tight junctions? |
Occludins |
|
Which cellular protein is found in desmosomes? |
Cadherins |
|
What is a glycerol with 3 fatty acids attached? |
Triglyceride |
|
What is the extensively branched polymer of hexose found in animals? |
Glycogen |
|
What two structural characteristics of proteins are formed by hydrogen bonds between carboxyl O and the amino H of amino acids within the same protein? |
a-helices : b-pleated sheets |
|
What spherical structures are involved in the transport of non polar molecules throughout the aqueous environment and are composed of a phospholipid monolayer? |
Micelles |
|
What are the three components of a nucleotide? |
5-carbon carbohydrate, phosphate, nitrogenous base |
|
Of the five bases found in nucleic acids, which are purines and which are pyrimidines? |
Pyrimidines = cytosine, thymine and uracil Purines = adenine and guanosine |
|
What type of integral membrane protein spans the membrane, thereby allowing part of it to face the cytosol and another part to face the extracellular fluid? |
Transmembrane protein |
|
What structure separates the nucleus from the cytosol? |
Nuclear envelope |
|
Through what structure in the nucleus can mRNA pass through to get into the cytosol? |
Nuclear pore |
|
What are masses of glycogen in the cytosol of some cells called? |
Inclusions |
|
The membrane of the rough endoplasmic reticulum is continuous with what other membrane(s)? |
Smooth ER and nuclear envelope |
|
What is the innermost chamber of a mitochondrion called? |
Matrix |
|
Components of the electron transport chain are found in what region of a mitochondrion? |
Inner mitochondrial membrane |
|
What organelle contains alcohol dehydrogenase, used in the liver to metabolize alcohol? |
Peroxisomes |
|
What two types of molecules make up ribosomes? |
rRNA and proteins |
|
Myosin is composed of what type of molecule? |
Intermediate filament |
|
Certain epithelial cells have a decided polarity where the ___ membrane faces the lumen of a hollow tube, whereas the ___ membrane faces the extracellular fluid. |
Apical : basolateral |
|
The CAP region of mRNA is necessary for ___ of translation |
Initiation |
|
What are the tRNA binding sites on the ribosome called? |
A and P sites |
|
What modifications made to mRNA function to prevent its degradation in the cytoplasm by exonuclease? |
CAP and poly A tail |
|
Proteins tagged with the polypeptide ____ are targeted for degradation by a protein complex called a proteasome. |
Ubiquitin |
|
Within the nucleus, chromosomes are coiled around which proteins? |
Histones |
|
What is the proper order of the five phases of mitosis? |
Prophase, prometaphase, metaphase, anaphase, telophase |
|
Sucrose is a disaccharide composed of a glucose and a lactose molecule. |
False |
|
Disulfide bridges contribute to the tertiary structure of proteins by covalent bonds between the sulfhydril groups on two cysteine amino acids |
True |
|
Cholesterol is the precursor molecule for all steroids in the body |
True |
|
Glycoproteins have a glycogen molecule covalently bound to a protein |
False |
|
Cyclic nucleotides form ring structures due to the covalent bonding between an oxygen of the phosphate group and a carbon of the carbohydrate |
False |
|
Thymine is a pyrimidine |
True |
|
Guanine and cytosine are held together by two hydrogen bonds |
False |
|
Inclusions are intracellular stores of glycogen or triglycerides |
True |
|
The innermost compartment of a mitochondrion is called the matrix |
True |
|
Vaults direct the development of the mitotic spindle during cell division |
False |
|
The cytoskeleton suspends the organelles within the cytoplasm |
True |
|
Movement between cells in an epithelium is called transepithelial transport |
False |
|
Anabolism describes the breakdown of large molecules to smaller molecules |
False |
|
Every adenine nucleotide of DNA will be transcribed into a thymine on the mRNA |
False |
|
The exon is cut from the original mRNA sequence, leaving the intron as the portion of mRNA that leaves the nucleus to be translated into a protein |
False |
|
The mRNA codon UUU codes for the amino acid phenylalanine. Therefore, no other codon can code for phenylalanine. |
False |
|
Each strand of mRNA is translated by one ribosome at a time. |
False |
|
The Golgi apparatus sorts and packages proteins into vesicles targeted for their final destination |
True |
|
The anticodon is complementary to the triplet coding for a particular amino acid |
True |
|
The hormone insulin is a peptide hormone consisting of two polypeptides held together by disulfide bridges |
True |
|
The semiconservative nature of the replication of DNA means that a new strand is coupled to an old strand |
True |
|
When insulin is first translated by ribosomes, the initial inactive polypeptide that is formed is called preinsulin |
False |
|
Bonding between Okazaki fragments forms the lagging strands of DNA |
True |
|
Helicase catalyzes the unwinding of DNA during transcription |
True |
|
Proteases break peptide bonds |
True |
|
Microtubules are dynamic structures in that they may form and disassemble repeatedly in a cell |
True |
|
The mitotic spindle forms from the centrosome during cell division |
False |
|
In the chemical equation A+B=C+D, the materials on the left-hand side of the equations are known as ___ whereas the materials on the right-hand side of the equation are known as ____ |
Reactants : products |
|
In the chemical equation A+B=C+D, the arrow indicates that the reaction is |
Bidirectional |
|
The sum of the thousands of chemical reactions that occur within the body is called |
Metabolism |
|
Making or synthesizing a protein would be considered a ___ reaction and the type of reaction that carries this process out is a ____ reaction |
Anabolic : condensation |
|
Which of the following is a correct description of an anabolic pathway? |
Glycogen is synthesized in the cytosol from glucose |
|
When phosphate is added to ADP to form the energy-storing molecule ATP, this is known as ____ and, since water is also produced, this reaction is also considered a ___ reaction |
Phosphorylation : condensation |
|
The addition of two hydrogens and two electrons to NAD+ is an example of what type of chemical reaction? |
Reduction |
|
Chemical reactions that involve the formation of peptide bonds between amino acids that produce water as a byproduct are called ___ reactions |
Condensation |
|
Chemical reactions that involve the production of a phosphate bond are called ___ reactions |
Phosphorylation |
|
Chemical reactions that involve the breaking of a phosphate bond are called ___ reactions |
Dephosphorylation |
|
In a reduction reaction, which of the following is most likely added to the reactants? |
Electrons |
|
During what type of reaction are electrons removed from the reactant? |
Oxidation |
|
Which of the following statements best represents the second law of thermodynamics? |
Natural processes tend to proceed in the direction that expands the energy. |
|
If the energy change of a reaction (deltaE) is positive, then |
The products had more energy than the reactants |
|
Which of the following is TRUE of an endergonic reaction? |
The change in energy of the reaction is positive |
|
The kinetic energy of a molecule can be increased by |
Increasing its temperature |
|
The energy that is stored within an object for later use is referred to as ___ energy |
Potential |
|
Which of the following statements about chemical equilibrium is FALSE? |
At equilibrium, the concentration of products equals the concentration of reactants |
|
Which of the following statements about the law of mass action is FALSE? |
Equilibrium is reached when the concentration of reactant equals the concentration of product |
|
Start with the following chemical reaction at equilibrium: A = B. If you add product B to the system from a separate pathway, then what change in the reaction occurs? |
The rate of the reverse reaction increases |
|
When tissue becomes more active, carbon dioxide increases due to its production in ____, causing hydrogen ion concentration to _____ |
Mitochondria : increase |
|
Molecules must have sufficient potential energy to overcome the ____ and, thereby, allow the reaction to proceed. |
Activation energy barrier |
|
An energy-releasing reaction is referred to as an ____ reaction |
Exergonic |
|
Decreasing temperatures will ____ the frequency of collisions between molecules, thereby ____ the reaction rate. |
Decrease : decreasing |
|
Reaction rates higher or lower than required by the body lead to disease states. How does the body regulate its metabolic needs? |
Reaction rates are regulated to match the body’s needs at a particular moment. |
|
As the energy required to overcome the activation energy barrier increases, the reaction rate will |
Decrease |
|
Enzymes act as a ____ to increase reaction rate |
Catalysts |
|
Which of the following would NOT increase the rate of a chemical reaction? |
Increasing the activation energy barrier |
|
Enzymes are what class of molecule? |
Proteins |
|
A substrate is the same as a |
Reactant |
|
How do enzymes speed up chemical reactions? |
By lowering the activation energy barrier |
|
In the induced-fit model for enzyme activity, the substrate alters the ____ of the _____ site on the enzyme |
Conformation : active |
|
The rate at which an enzyme-catalyzed reaction occurs can be increased by |
Increasing enzyme concentration |
|
The measure of how many product molecules can be produced by an enzyme per unit of time is referred to as that enzyme’s |
Catalytic rate |
|
Not all enzymes have substrate specificity. For example, pepsin can breakdown numerous types of proteins in the stomach. What concept best describes why the single enzyme pepsin can breakdown so many proteins? |
The induced-fit model |
|
Which of the following would decrease the rate of an enzyme-catalyzed reaction? |
Increasing the concentration of product |
|
Some enzymes require trace metals to function as cofactors. What do the trace metals do? |
Trace metals must be present in the enzyme in order for the enzyme to bind substrates. |
|
Coenzyme A is derived from which of the following vitamins? |
Pantothenic acid |
|
What are coenzymes? |
Organic molecules derived from vitamins that function in the transfer of a chemical group |
|
The greater the attractive forces between substrate and enzyme, that enzyme is said to have a higher ____ for the substrate |
Affinity |
|
Many drugs are manufactured that tend to bind to an enzyme’s active site more quickly than the substrate the enzyme normally binds. What quality allows the drug to be attracted to the active site more readily than the substrate? |
Affinity |
|
Enzymes are proteins. If the enzyme concentration is increased, the rate of activity of the enzyme will increase exponentially as long as there is substrate to bind. How does the body increase the enzyme concentration? |
Through protein synthesis |
|
A drug that blocks the active site of an enzyme and does not allow a product to be produced is known as |
Allosteric inhibitor |
|
If the graph of an enzyme-catalyzed reaction shows a sigmoidal relationship between substrate concentration and reaction rate, then what can be said about the reaction? |
It is allosterically regulated |
|
In allosteric regulation, the modulator molecule binds to the |
Regulatory site of the enzyme by weak, reversible interactions |
|
Regulation of an enzyme through reversible binding of a modulator to a regulatory site on an enzyme is specifically called |
Allosteric regulation |
|
Regulating an enzyme through protein kinase-induced phosphorylation of that enzyme is an example of |
Covalent regulation |
|
In a metabolic pathway, the enzyme working the slowest in that pathway is known as the ___ enzyme. |
Rate-limiting |
|
A protein kinase catalyzes which of the following types of chemical reactions? |
Phosphorylation |
|
Which of the following statements about end-product inhibition is FALSE |
The amount of product produced is increased by this process |
|
In a metabolic pathway, both ____ help to keep reaction rates within normal ranges by either speeding them up or slowing them down. |
Feedforward activation and feedback inhibition |
|
During end-product inhibition, |
The final product of an enzyme-catalyzed reaction inhibits the rate-limiting enzyme via allosteric regulation |
|
What is the most important energy-transferring compound in cells? |
Adenosine triphosphate |
|
In skeletal muscle, ATP can be synthesized by transferring a phosphate group from creatine-P to ADP to form ATP and creatine. In this example, ATP was synthesized by what process? |
Substrate-level phosphorylation |
|
The complete oxidation of glucose releases how many kcal of energy for every mole of glucose? |
686 |
|
What is the major physiological importance of breathing? |
Oxygen must be present in our cells to break down food into energy |
|
Where does glycolysis occur |
Cytosol |
|
ATP is synthesized by substrate-level phosphorylation during which of the following? |
Glycolysis and the Krebs cycle only |
|
Which of the following does NOT occur in mitochondria? |
Conversion of pyruvate to lactate |
|
The final product of glycolysis under aerobic conditions is pyruvate. What happens to pyruvate under aerobic conditions? |
Pyruvate enters the mitochondrial matrix where it is converted into acetyl CoA |
|
In the presence of oxygen, the process of glycolysis produces which of the following products? |
2 pyruvate |
|
Where are the enzymes of glycolysis located within the cell? |
Cytosol |
|
In the presence of a limited oxygen supply, pyruvate is converted to what? |
Lactate |
|
How many ATP are generated per acetyl coenzyme A going through the Krebs cycle followed by the electron transport system? |
12 |
|
In terms of energy production, the Krebs cycle is significant because |
it reduces the coenzymes NAD and FAD for oxidative phosphorylation |
|
What is the final acceptor of electrons in the electron transport? |
Oxygen |
|
Where is the electron transport chain? |
Inner mitochondrial membrane |
|
Cyanide is a deadly poison that attaches to cytochrome c oxidase, the last protein in the electron transport chain before the terminal electron acceptor. Based on your knowledge of the electron transport chain, which statement below best describes the action of cyanide on the body? |
Cyanide blocks the terminal electron acceptor oxygen and therefore will halt the production of ATP. The majority of ATP is normally produced in the electron transport chain and without it the body will begin to only go through glycolysis and start producing lactic acid and will eventually shut down due to a lack of ATP to run the body and because of the buildup of acid in the system. |
|
Chemiosmotic coupling refers to |
The harnessing of energy from the reactions of the electron transport chain to make ATP |
|
Hydrogen ions activate the enzyme ATP synthase by moving from |
Inter membrane space to mitochondrial matrix |
|
Each time an electron is passed between the molecules of the electron transport chain, |
Energy is released |
|
What is the first component of the electron transport chain that accepts electrons from an NADH molecule? |
Flavin mononucleotide |
|
What is the first component of the electron transport chain that accepts electrons from an FADH2 molecule? |
Coenzyme Q |
|
ATP synthase is able to use the potential energy that originates from ___ to produce ATP. |
The hydrogen gradient across the inner mitochondrial membrane |
|
Under low oxygen conditions, ___ must unload its electrons to allow glycolysis to continue the production of ATP |
NADH |
|
What is the net energy yield for the anaerobic metabolism of one glucose molecule? |
2 molecules of ATP and 0 NADH |
|
Under anaerobic conditions, what is pyruvate converted to and where does this occur? |
lactate in the cytosol |
|
Under anaerobic conditions, which of the following is a final product of glucose catabolism? |
Lactic acid |
|
How is glucose stored in muscle and liver cells? |
Glycogen |
|
Glycogen in muscle is used to |
fuel the activity of that muscle exclusively |
|
Which of the following contains glucose-6-phosphatase? |
Liver |
|
What is the function of glucose-6-phosphatase? |
Catalyze removal of one phosphate group from glucose |
|
Which of the following molecules is NOT converted to glucose through the process of gluconeogenesis? |
Fatty acids |
|
What is glycogenolysis? |
The breakdown of glycogen to glucose |
|
Which of the following molecules is a substrate for gluconeogenesis |
Amino acids and glycerol only |
|
Gluconeogenesis refers to synthesis of ___ and occurs in ___ |
Glucose : the liver |
|
The conversion of triglycerides to glycerol and fatty acids is called |
Lipolysis |
|
A substantial amount of ATP is generated from the metabolism of long carbon chains called |
Fatty acids |
|
Metabolism of fatty acids that result in the accumulation of acetyl CoA can lead to a buildup of |
Ketones |
|
Beta-oxidation of a 14-chain fatty acid results in how many acetyl CoA molecules? |
7 |
|
Where does beta-oxidation of fatty acids occur? |
Mitochondrial matrix |
|
Before converting amino acids into intermediates for energy metabolism, they must first undergo |
Deamination |
|
Any nutrient that is not synthesized by the body and must therefore be acquired through the diet is an ____ nutrient |
Essential |
|
The amine group removed from an amino acid must be converted to ___ before being eliminated from the human body |
urea |
|
Insulin levels in the blood are elevated in response to which of the following? |
increased blood glucose levels |
|
Acetyl CoA is the initial substrate in what linking step of metabolism? |
Krebs cycle |
|
Pyruvate is the final product of what stage of glucose oxidation? |
Glycolysis |
|
What process occurs within the inner mitochondrial membrane? |
Electron transport chain |
|
Glucose is synthesized by what process? |
Gluconeogenesis |
|
What process uses glucose to synthesize a larger molecule? |
Glycogenesis |
|
Where within the cell does glycolysis occur? |
Cytosol |
|
Where within the cell does the Krebs cycle occur? |
Mitochondrial matrix |
|
Where within the cell does the electron transport chain occur? |
Inner mitochondrial membrane |
|
Where within the cell does the conversion of pyruvate to lactate occur? |
Cytosol |
|
Where within the cell does the conversion of pyruvate to acetyl CoA occur? |
Mitochondrial matrix |
|
Identify the following reaction by its type: protein+h20=amino acids |
Hydrolysis |
|
Identify the reaction: monounsaturated fatty acid + 2H = saturated fatty acid |
Reduction |
|
Identify the reaction: |
Phosphorylation |
|
Identify the reaction: |
Condensation |
|
Identify the reaction: |
Reduction |
|
Identify the reaction: |
Oxidation |
|
Given the following: a+b=c+d how will this reaction be altered if an excess of C is added to the reaction |
It will drive the reaction in reverse |
|
Given the following: a+b=c+d how will this reaction be altered if an excess of B is added to the reaction |
It will drive the reaction forward |
|
In order for a reaction to proceed past the transition state, the reaction must overcome what energy barrier? |
the activation energy barrier |
|
Metabolism includes ___ reactions, which release energy and result in the breakdown of large biomolecules, and ___ reactions, which require a net input of energy and result in the synthesis of large biomolecules |
Catabolic : anabolic |
|
When a substrate binds to a protein via weak interactions, the substrate is referred to as a |
ligand |
|
An enzyme that catalyzes phosphorylation of a protein is called a |
Kinase |
|
An enzyme that catalyzes dephosphorylation of a protein is called a |
Phosphatase |
|
During _____, a phosphate group is transferred from a metabolic intermediate to an ADP to synthesize ATP |
substrate-level phosphorylation |
|
Glucose is stored in the form of glycogen primarily within what two organs? |
Skeletal muscles and liver |
|
The synthesis of glucose from non-carbohydrate precursors is called ____ and it occurs in the ____ |
Gluconeogenesis : liver |
|
A–B + H2O = A–OH + H–B describes what type of reaction? |
Hydrolysis |
|
A–OH + H–B = A–B + H2O describes what type of reaction? |
Condensation |
|
When a reaction occurs and that reaction is moving equally in a forward and reverse direction, that reaction is said to be at |
Equilibrium |
|
What is the strength of binding between an enzyme and substrate called? |
Affinity |
|
What chemical group is most commonly added to a protein during covalent regulation? |
Phosphate |
|
How many ATP are produced for each acetyl coenzyme A completely catabolized in the presence of oxygen? |
12 |
|
Proteins are broken down to amino acids by |
Proteolysis |
|
In the liver, ammonia is converted to ___ for eventual elimination in the urine |
urea |
|
What is the storage form of carbohydrates in animal cells? |
Glycogen |
|
The organ that stores glucose as glycogen and then provides glucose to the blood when needed is the |
liver |
|
Chemical reactions are only able to occur in one direction |
False |
|
Phosphorylation reactions are specific examples of a condensation reaction |
False |
|
Sucrose is synthesized from the condensation of fructose and glucose |
True |
|
According to the first law of thermodynamics, energy cannot be created or destroyed |
True |
|
Potential energy describes the energy possessed by an object in motion |
False |
|
A reaction is at equilibrium when the rates of the forward and reverse reactions are equal |
True |
|
Energy-releasing reactions occur spontaneously |
True |
|
Energy-requiring reactions will always proceed spontaneously in the forward direction |
False |
|
An increase in the concentration of a product will increase the rate of a reaction in the reverse direction |
True |
|
An increase in temperature increases the potential energy of molecules |
False |
|
Most enzymes only catalyze reactions in one direction |
False |
|
An increase in the affinity of an enzyme for its substrate will increase the reaction rate |
True |
|
According to the induced-fit model for enzymes, the binding of substrate to the active site alters the structure of the enzyme |
True |
|
A single enzyme could be simultaneously affected by both allosteric regulation and covalent regulation |
True |
|
Enzymes increase the activation energy of a reaction |
False |
|
An increase in the concentration of enzyme will increase the reaction rate |
True |
|
Binding of a modulator to a regulatory site alters the structure of the enzyme in a way that can affect catalytic rate and/or affinity |
True |
|
Addition of a phosphate group to an enzyme to change its activity is an example of covalent regulation |
True |
|
Protein kinases target phosphorylation in covalent regulation reactions |
True |
|
All of the energy released by the oxidation of glucose is converted and stored in the form of ATP |
False |
|
ATP stores energy |
True |
|
Glycogenolysis is an example of a catabolic reaction |
True |
|
Lactate dehydrogenase is an enzyme in the mitochondrial matrix |
False |
|
What is responsible for the unequal distribution of ions across a membrane, thereby causing a charge? |
The concentration of impermeable charged molecules |
|
The chemical force for which of the following ions is directed into the cell? |
both sodium and calcium |
|
Which of the following is found in greater concentration inside the cell than outside? |
Potassium |
|
When molecules are passively transported across a membrane, the direction of their movement is dictated by the molecule’s tendency to move |
From higher to lower energy |
|
Of the gradients listed below, which is the MOST accurate description of the force that ultimately determines the movement of ions across the membrane? |
Electrochemical gradient |
|
Molecules tend to move spontaneously ___ their chemical gradient |
Down |
|
When more than one ion species (i.e. Na+ and K+) is present on both sides of the membrane, the chemical driving force acting on Na+ will include |
Sodium only |
|
Which of the following is a reflection of the unequal distribution of positive and negative ions across the plasma membrane? |
Membrane potential |
|
Comparing intracellular to extracellular fluid, the intracellular fluid has a ___ charge relative to the outside of a cell due to the presence of more ___ in that solution |
negative : anions |
|
The unequal distribution of charge in solutions on either side of a membrane will lead to a ___ of charge across the membrane and a ____ of counter ions in a region close to the membrane |
Separation : clustering |
|
If the solutions on either side of the membrane have an unequal distribution of charged ions, with the inside having an excess of anions, then the inside of the cell would have to be |
More negative, relative to the outside of the cell |
|
As an ion moves passively across a membrane into the cell, the progressive increase in concentration within the cell will |
Decrease the net flux across the membrane |
|
Based solely upon its electrical charge, the inside of a typical cell will tend to attract extracellular ___ to move inward |
Cations |
|
Which of the following is NOT a determinant of the magnitude and direction of the equilibrium potential for an ion? |
lipid solubility of the ion |
|
If a positively charged ion is more concentrated outside the cell, the electrical forces required to balance the chemical gradient would be directed ____. Thus, the equilibrium potential for this ion would be _____ charged |
Outward : positively |
|
Which of the following cells would have a greater electrical attraction for sodium ions to enter the cell? |
Cell with membrane potential = -90 mV |
|
If a positively charged ion is more concentrated inside the cell, the electrical forces required to balance the chemical gradient would be directed ____. Thus, the equilibrium potential for this ion would be____ charged |
Inward : negatively |
|
Which of the following can be used to determine an ion’s equilibrium potential? |
Nernst equation |
|
The potassium equilibrium potential is -94 mV. What does this mean? |
At -94 mV, the chemical force for potassium movement is opposed exactly by the electrical force |
|
Chloride has an equilibrium potential of -90 mV. What direction are the chemical and electrical forces acting on the anion at the resting membrane potential (-70 mV)? |
The chemical force is directed into the cell and the electrical force is directed out of the cell |
|
What effect would increasing the extracellular concentration of K+ have on the resting membrane potential? |
The RMP would become more positive (less negative) |
|
An anion is found in greater concentration inside the cell than outside. Which of the following BEST describes forces acting on the anion at the resting membrane potential (-70mV)? |
Both the chemical and electrical forces are directed out of the cell |
|
The equilibrium potential for a cation is +120 mV. Which of the following is true when a cell is at the resting membrane potential (-70mV)? |
Both the chemical and electrical forced are directed into the cell |
|
The equilibrium potential describes the membrane potential where what two forces are balanced? |
Chemical and electrical |
|
Which of the following is NOT required to determine equilibrium potential for a particular ion? |
Size of the ion |
|
Which of the following would NOT increase the rate of simple diffusion across the phospholipid bilayer of the plasma membrane? |
Greater number of protein carriers |
|
Which of the following pairs of characteristics is more likely to make a substance diffuse through the cell membrane? |
Small, non-polar molecule |
|
Oxygen diffuses from blood into cells down ints concentration gradient. As cells become more active and oxidative phosphorylation increases in the cell, which of the following occurs? |
The concentration gradient for oxygen increases and oxygen movement into the cell increases |
|
As a cell’s metabolism increases, so does its O2 consumption, giving rise to what product at a ratio of 2:1? |
H20 |
|
If a molecule crosses a membrane and is quickly removed from the area by the blood stream or some biological pathway, what effect does this have on its rate of diffusion? |
Diffusion rate will increase |
|
The diffusion rate is |
the speed at which diffusion takes place |
|
The concentration of sodium is greater in the extracellular fluid compared to the intracellular fluid. If the membrane potential was equal to the equilibrium potential for sodium, then what would be the direction of the electrochemical force acting on sodium? |
equal in both directions |
|
If a cell’s Na+/K+ pump worked in reverse and had more leak channels for Na+ than for K+, what would the ion concentrations of the cell look like? |
Although the body tries to maintain an extracellular concentration of Na at 145 mM, the intracellular concentration of Na would still be higher |
|
One way that membrane surface area is increased in absorptive cells is through increasing the ___ of the apical membrane |
folding |
|
When a substance crossing the membrane is driven by diffusion, the net flux of that molecule can be described mathematically by |
Fick’s law |
|
Which of the following will NOT increase the net flux of an ion across a membrane? |
reduced surface area |
|
Molecules with a relatively high lipid solubility are capable of crossing the membrane |
directly through the lipid bilayer |
|
With pulmonary hypertension, the lung’s capillary walls become thicker to compensate for the higher pressure. What does fick’s law suggest will happen to CO2 concentrations? |
CO2 levels in the blood will increase |
|
Which of the following molecules is LEAST likely to diffuse through the phospholipid bilayer of the plasma membrane? |
disaccharide |
|
Which of the following is NOT true for all three of these transport mechanisms: facilitated diffusion, primary active transport, and secondary active transport |
The transport mechanism requires energy |
|
Which of the following transport mechanisms is passive |
movement of sodium through ion channels |
|
A carrier is a transmembrane protein that moves molecules across the membrane through |
conformational changes in its protein shape |
|
In general, the molecules that move through specific carrier proteins are determined by which of the following |
the unique fit to binding sites on the channel or carrier protein |
|
In facilitated diffusion, a molecule is moved |
down its concentration gradient with the assistance of a protein carrier molecule, and no energy is required |
|
Which of the following transport mechanisms require energy |
both primary and secondary active transport |
|
Transporting a substance against its concentration gradient requires |
a transporter that uses energy |
|
In active transport, the affinity of the carrier protein for the molecule being transported is greater on which side of the membrane |
on the side where the molecule is in lower concentration |
|
During cotransport of glucose with sodium, sodium increases the affinity of the carrier molecule for glucose when the binding site is facing which side |
the extracellular fluid |
|
When the Na+/K+ pump moves its bound molecules of Na+ to the outside of the membrane, it |
cannot return to the inside empty-handed, so it must bind two K+ first |
|
Most water molecules that cross the plasma membrane do so by |
diffusion through aquaporins |
|
What transport process couples the movement of an ion against its electrochemical gradient to another ion that is moving down its electrochemical gradient that has established using ATP |
Secondary active transport |
|
The first step of the Na+/K+ pump’s activity involves the binding of which of the following |
3 Na to their binding site on the inside of the cell |
|
The hydrolysis of ATP on the Na/K pump results in |
conformational change that exposes the Na binding site to the outside of the cell |
|
Na is released from its binding site on the Na/K pump as a result of the |
conformational change decreasing the affinity of the Na binding site |
|
If a cell becomes damaged and is temporarily unable to produce ATP, what is the likely outcome with respect to h20 |
cellular swelling, as water follows Na into the cell |
|
Which of the following statements about Ca2+ pumps is FALSe |
calcium is actively transported from an organelle into the cytosol |
|
In secondary active transport with sodium, which of the following is FALSE |
The molecule being transported moves down its electrochemical gradient |
|
Which of the following statements about glucose cotransport with sodium is true |
glucose and sodium both move into the cell |
|
The concentration of the anion inside a cell is 0.3%. The concentration of this anion outside the cell is 0.1% How could the cell obtain more of this ion inside the cell |
Active transport |
|
What effect does uncontrolled diabetes mellitus have on blood osmolarity? |
It increases it, causing a hyperosmotic state compared to normal |
|
All of the following statements concerning severe hyperglycemia’s effect on serum Na levels are true, except |
administering a hypertonic saline would help compensate for the decreased Na levels |
|
The sodium-proton exchanger is an example of a |
antiporter |
|
The flow of water across a membrane down its concentration gradient is called |
osmosis |
|
A cell with normal tonicity is placed in a 200 mM NaCl solution. The solution is __ and the cell will ___ |
hypertonic : shrink |
|
If a solution contains 0.1 M glucose along with 0.15 M NaCl what is the osmolarity of this solution |
400 mOsm |
|
If there is a difference in osmolarity between a cell and its environment, water will move ___ its osmotic pressure gradient |
up |
|
The osmotic pressure of a solution is a |
indirect measure of its solute concentration |
|
A cell is placed into a solution that has the same osmolarity. However, one of the solutes in the solution is able to move across the membrane (the cell does not contain this solute). after a period of time, the solution into which the cell was placed would become |
hypotonic |
|
White blood cells are an important component of our immune system. One thing they do is consume and destroy bacteria by expanding their plasma membrane around the bacterium and bringing it inside the cell in a vesicle. By what process do they engulf the bacterium |
phagocytosis |
|
When white blood cells are called to an area of infection, not only is there phagocytosis taking place, but also exocytosis of undigested particles from the white blood cells into the interstitial space. What effect does this have on water in the surrounding cells and capillary plasma? |
It creates a hypertonic environment, drawing water from the surrounding cells and plasma |
|
Vesicles formed during phagocytosis or endocytosis often fuse with the membrane of which of the following organelles? |
Lysosome |
|
Endocytosis is a dorm of active transport to move vesicles |
filled with particles and/or fluids into the cell |
|
Secretory vesicles are a part of what transport mechanism |
exocytosis |
|
Epithelial cells are polarized with different structures at either end of the cell. The portion of the membrane that faces the lumen is called the ____ |
apical membrane |
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The extent of ion movement through the ___ space between epithelial cells is determined by the extent of ___ coupling between neighboring epithelial cells |
paracellular : tight junctional |
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The electrochemical gradient is to diffusion as ___ is to active transport |
ATP |
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When solute is actively transported across epithelium, what usually follows? |
water movement in the same direction |
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All of the following solutes are found in higher concentration outside of the cell except |
proteins |
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All of the following solutes are found in higher concentration inside of the cell except |
calcium |
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Which of the following transport mechanisms requires energy |
phagocytosis |
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Which of the following transport mechanisms has no energy requirement |
osmosis through aquaporins |
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Which of the following solutions bathing a red blood cell would be considered isotonic? |
a solution containing 100 mM MgCl2 |
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Which of the following descriptions would be an example of receptor-mediated endocytosis? |
a low-density lipoprotein that becomes internalized by a hepatic cell |
|
Which of the following would be an example of phagocytosis? |
bacteria that is engulfed by a white blood cell |
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Which of the following would be an example of exocytosis? |
acetylcholine released from a neuron |
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Which of the following would be an example of pinocytosis? |
a macrophage drinking its surrounding tissue fluid and nutrients |
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The process of diffusion involves the random movement of |
individual molecules due to thermal motion |
|
As the molecular weight of a molecule increases, its |
membrane permeability decreases |
|
What effect does a cell’s overall thickness have on its permeability? |
As the cell’s thickness increases, its permeability decreases |
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What is the meaning of carrier proteins and pumps becoming saturated? |
These transporters have reached a maximal net flux, beyond which further increases in concentration no longer affect their rate |
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Why are primary active transporters many times called ATPases? |
they act as enzymes to release energy from ATP |
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What is the primary role for the Na/K pump? |
the maintenance of Na and K concentrations on either side of the membrane |
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Which condition exists when there are more solutes present in a solution |
There is a lower concentration of water in that solution |
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During phagocytosis, the phagosome binds with a ___ to form a_____ |
lysosome : phagolysosome |
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In epithelial tissue, the cells are linked together by ___, which prevent paracellular movement from lumen to extracellular fluid |
tight junctions |
|
In epithelial tissue, the portion of the plasma membrane facing the lumen is called the |
apical membrane |
|
The portion of the plasma membrane facing the connective tissue/interstitial fluid is called the |
basolateral membrane |
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Insulin triggers the insert of what protein into the cell membrane of its target cell? |
GLUT4 |
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The movement of a molecule is determined by its energy state, with that molecule moving from a higher to a lower energy state |
True |
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In the presence of two or more ions, it is the sum of their concentration that determines the direction of movement of those ions across a membrane |
False |
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Most of the time, the body is neutral with respect to its electrical charge due to the equal distribution of anions and cations within the body |
True |
|
The total amount of anions and cations in the body to keep it electrically neutral is maintained by homeostasis |
False |
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If the membrane potential is equal to the equilibrium potential for an ion, individual ions will NOT move across the membrane in either direction |
False |
|
Osmosis occurs through aquaporins |
True |
|
In chemical communication between cells, a ___ cell secretes a chemical messenger that binds to __ on the __ cell |
Secretory : receptors : target |
|
Direct communication between cells in contact with one another is accomplished through |
Gap junctions |
|
The number of bound receptors on a target cell depends on what two things? |
the concentration of the messenger and the concentration of receptors on the target cell |
|
Which type of chemical messenger, when released, binds to receptors on the cell that released the chemical messenger? |
autocrine |
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Which type of chemical messenger is released into the bloodstream by an endocrine gland where it can affect target cells throughout the body? |
Hormone |
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Which type of chemical messenger is released from the axon terminal of a neuron and directly communicates with other cells? |
Neurotransmitter |
|
Communication across a synapse is initiated by the release of a neurotransmitter from the ___ region of the neuron |
axon terminal |
|
Vasopressin, which is released from the posterior pituitary, is an example of what type of chemical messenger |
neurohormone |
|
Inflammation is characterized in part by redness and swelling. In inflammation, ___ increases blood flow to affected tissues and causes fluid to leak out of the blood vessels and into the tissue. |
histamine |
|
The more specific a drug is for a certain ___ type, the more specific the therapeutic actions of the drug and the fewer the side effects |
receptor |
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Which of the following chemical messengers is lipophilic and is therefore able to cross the cell membrane? |
eicosanoids |
|
Histamine acts as a ___ in its role in inflammation |
paracrine |
|
What molecules are hydrophobic and can easily cross the plasma membrane? |
lipophilic |
|
All the messengers in what class are derived from cholesterol? |
steroids |
|
peptide hormones are made ___, stored and released via ___ |
in advance : exocytosis |
|
Cells that secrete dopamine must contain which enzymes? |
tyrosine b-hydroxylase and dopa decarboxylase |
|
Cells that secrete epinephrine must contain which enzymes? |
dopamine b-hydroxylase, tyrosine b-hydroxylase, phenylethanolamine n-methyl transferase, and dopa decarboxylase |
|
Catecholamines are derived from what amino acid? |
tyrosine |
|
thyroid hormones are synthesized from what amino acid |
tyrosine |
|
Aspirin is a nonsteroidal anti-inflammatory drug that relieves pain. Which mechanism best describes how it works? |
Prostaglandins are eicosanoids that produce pain and inflammation. cyclooxyrgenase is an essential enzyme in the production of PG and aspirin inhibits COX and therefore relieves pain due to the reduced production of PG |
|
Once a steroid hormone is synthesized, it is |
immediately capable of diffusing across the membrane |
|
What organelle packages peptide/protein messengers into secretory vesicles? |
Golgi apparatus |
|
An equilibrium exists between a hormone that is bound to a carrier protein and a free hormone such that, as the amount of free hormone increases, |
more free hormone will become bound to carrier proteins |
|
Lipophilic chemical messengers are poorly soluble in water. However, many of these lipophilic messengers are transported throughout the body. Their transport in blood (water) is facilitated by |
carrier proteins |
|
What enzyme catalyzes synthesis of prostaglandins from arachidonic acid |
cyclooxygenase |
|
A half-life, in terms of a chemical messenger, refers to |
the time it takes for half of the chemical messenger in the blood to be degraded |
|
Androgens are precursor molecules for the synthesis of |
estradiol |
|
progesterone is a potential precursor for the synthesis of |
cortisol |
|
Aspirin decreases inflammation by inhibiting the actions of what enzyme |
cyclooxygenase |
|
hormones that are dissolved in the blood typically exhibit a half-life on the order of ____, whereas hormones that are bound to carrier proteins can remain undegraded for ____ |
minutes : hours |
|
The location of receptors on a target cell depends on the solubility of the chemical messenger. Where would the receptors for lipophilic messengers be located |
on the inside of the cell |
|
Which of the following will NOT affect the magnitude of a cell’s response to a specific hydrophilic ligand |
lipid solubility of the ligand |
|
Chronic exposure to a ligand ___ the receptor population for that chemical messenger on the target cell |
down regulates |
|
Which best describes the release of lipophobic messengers? |
Lipophobic messengers are stored in vesicles and released by exocytosis in response to a stimulus |
|
Which best describes the release of lipophilic messenger? |
released immediately upon synthesis by simple diffusion |
|
What is a molecule that is similar in structure to a messenger and binds with that messenger’s receptor to stimulate a similar response from the target cell |
agonist |
|
The magnitude of a target cell’s response to a chemical messenger depends on which three factors |
the concentration of the messenger, the number of receptors, and the affinity of the receptor for the messenger |
|
The affinity of a receptor for its ligand is a measure of the |
strength of binding between ligand and receptor |
|
Typical responses to ___ messengers require a long time to develop because they necessitate transcription of mRNA and translation of that mRNA into a functional protein |
lipophilic |
|
Differences in the rate of activity between fast and slow ligand-gated channels are caused by |
G protein activity gating the slow channel |
|
Opening channels for which of the following ions can trigger exocytosis |
… |
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