AAMC B-B

gastrointestinal epithelial cells

Out of adipocytes, cardiac muscle cells, neurons, and gastrointestinal epithelial cells, which of these are typically highly proliferative?

phosphodiester

after a section of a DNA strand containing a UVR-induced lesion is removed and resynthesized, the newly synthesized strand is rejoined to the remainder of the DNA strand by what type of bond?

phosphodiester

which bonds link the 3′ carbon atom of deoxyribose and the 5′ carbon atom of another deoxyribose within the DNA molecules

PH < 4

Given that H+ is a reactant, an increase in the concentration of H+ at low PH will favor product formation

AIP exposed to an aqueous solution in which PH range will result in the largest amount of phosphine production, given that the reaction is: AIP + 3H+ –> Al3+ + PH3

cysteine

Which amino acid side chain contains sulfhydryl groups:

lysosome

A large carbohydrate is tagged with a fluorescent marker and placed in the extracellular environment surrounding a eukaryotic cell. The cell ingests the carbohydrate via endocytosis to form an endocytic vesicle. Upon viewing the cells with a microscope, which of the following cellular substructures is most likely to be fluorescently labeled?

the material becomes entrapped in a phagosome which then fuses with a lysosome to form a phagolysosome, where enzymes digest the foreign object

Describe what occurs when a macrophage ingests foreign material

allosteric regulation, feedback inhibition

The inhibition of PFK-1 by ATP is an example of:

osmosis, diffusion, facilitated diffusion

In which processes can ions move along their concentration gradient, either with or without the help of transport proteins

the membrane would fail to repolarize, extending the length of the action potential and simulating excessive muscle contractions

What would result if potassium ion channels are blocked, as a result of being exposed to dendrotoxin?

they are positively charged at physiological PH

Given that Wnt proteins are a family of secretory proteins with isoelectric points around 9, what can be assumed?

RER

Where are secretory proteins synthesized?

RER

Where do secretory proteins fold into their tertiary structure?

it contains a nuclear localization sequence; as transcription factors are found in the nucleus, beta-catenin must enter the nucleus. Proteins that are translocated into the nucleus usually contain a nuclear localization sequence

Beta-catenin activates transcription factors for Wnt target genes, what does this indicate about beta-catenin?

nonpolar (hydrophobic) residues

The middle region, as opposed to either end, of each of the seven alpha-helical domains of Frizzled is most likely to contain a high proportion of which type of amino acid residue?

cysteine

What is the only amino acid that can form covalent linkages?

the proton gradient across the inner membrane will dissipate; protein X forms membrane-spanning channels that alter the permeability of the inner membrane, thereby dissipating the proton gradient across the inner membrane

What event will most likely occur if Protein X is inserted into the inner membrane of mitochondria?

the reversible conversion of glyceraldehyde-3-phosphate to 1,3-biphosphoglycerate

glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyzes:

western blot

What is the best experimental method to analyze the effect of tdh2 gene deletion on the rate of histone acetylation? Comparing histone acetylation in WT and tdh2 cells by:

Western blotting

postranslational modification of proteins such as histone acetylation is analyzed by:

collecting duct

Vasopressin regulates the insertion of aquaporins into the apical membranes of the epithelial cells of which renal structure?

collecting duct

What is responsible for regulating the fusion of aquaporins with the apical membranes of the collecting duct epithelial cells

Schwann cells

What are primary myelin-forming cells in the peripheral nervous system?

protein

A prion is best described as an infectious:

an abnormally folded protein that induces a normally folded version of the protein to also adopt the abnormal structure, which is often deleterious

What is a prion?

Liver

Assume that S. typhi immediately enters the bloodstream from the small intestine. Of the following, which would be the first major organ that bloodborne S. typhi would encounter?

The liver

nutrient distribution and toxin removal from the blood

Where is blood from the small intestine first transported to? What are two functions of this structure?

for chloramphenicol resistance in populations of S. typhi

Researchers have noted that chloramphenicol (antibiotic) is becoming less effective in treating typhoid fever (causative agent is S. typhi). The best explanation for this observation would be selection:

endosomes

Internalization of viral particles through endocytosis is mediated by:

digest proteins into smaller fragments

What is the function of a protease?

glycolysis

Phosphoenolpyruvate is a product of:

CTA

malate, succinate, and alpha-ketoglutarate are products of:

6e24; if 2 moles of ATP are produced from each mole of glucose, then 2 x 5 = 10 moles and since there are 6e23 molecules per mole, then 10 moles of ATP is equal to 6e24

Under anaerobic conditions, how many molecules of ATP are produced by the consumption of 5 moles of glucose?

genome size

In humans, eggs and sperm are most similar with respect to:

they both contain a haploid number of chromosomes

why are eggs and sperm similar with respect to their genome size?

mesoderm

The heart, kidney, and skeletal muscle are derived from the:

motor protein

Myosin is a:

degradative enzymes that function at low PH

Secretory lysosomes are classified as lysosomes because secretory lysosomes have some functional components in common with conventional lysosomes. Given this, secretory lysosomes most likely contain:

membrane-bound organelles that contain hydrolytic enzymes activated by a low PH

Define lysosomes:

centrosome

Melanosomes most likely move along microtubules that originate in and radiate from the:

viral antigens presented on the surface of virus-infected cells

lytic granules are generally released from CTLs when the T-cell receptors on these cells bind specifically to:

by recognizing the viral antigen presented on the cell surface

How do cytotoxic T lymphocytes target virus-infected cells?

one constant and one variable domain from each heavy and light chain of the antibody

What is the variable/Fab region (fragment, antigen-binding) region composed of:

epididymis

Where in the human male reproductive system do the gametes become motile and capable of fertilization?

seminiferous tubules of the testes

Where is sperm produced?

the myosin head from the actin filament

According to the cross-bridge model of muscle contraction, the muscles stiffen after death because ATP is unavailable to bind and directly release:

failure to release the myosin head from the actin filament due to no new ATP production

What causes rigamortis?

adding a reducing agent; a reducing agent would eliminate any disulfide bridges and allow the monomers to run separately-thus leading to a migration expected for the 22.5-kDa protein

A homodimeric protein was found to migrate through SDS polyacrylamide gel electrophoresis (SDS-PAGE) with a mobility that matched that of a 45-kDa standard. What change in the experiment would increase the chances of observing the mobility expected for the 22.5-kDa monomer?

vasodilation and muscle relaxation

Actin depolymerization leads to:

moderates blood flow to the brain under high pressure

Which statement best describes the function of the MR (myogenic response) response to stimulation of the sympathetic nervous system?

aorta

Where is blood pressure highest at in the body?

brain and skeletal muscles

During activation of the sympathetic system, where is blood flow directed towards?

actin

What are microfilaments composed of?

aspartate; it has a negatively charged R group and is very hydrophillic

Which amino acid is least likely to be found in one of the transmembrane domains of CPCR43?

alanine

Which amino acid contains an unbranched alkyl side chain?

because it contains a methyl side chain

Why is alanine not considered a branch alkane?

epimers at an anomeric carbon atom

The stereochemical designators alpha and beta distinguish between:

between molecules with multiple chiral centers, but differ only in the configuration of the site known as the anomeric carbon atom

What does the D versus L designation distinguish?

Influx of Na+ across the motor end plate resulting in the depolarization of the muscle fiber membrane

Which event is directly mediated by a ligand-gated ion channel?

through Na+ ion channels binding the ligand acetylcholine

How does Na+ influx across the motor end plate occur?

AAGCTT

recognition sequence for HindIII restriction enzyme

a 4-6 nucleotide long sequence in the 5′-3′ direction on both strands, a restriction enzyme cuts here

What is a palindromic sequence?

southern blot

Which technique uses a restriction digest to differentiate between mutant and WT alleles

P-O

What bond is cleaved by IN during the first reaction of integration?

P-O

cleaving a dinucleotide from the 3′ end of a strand of viral DNA involves the cleavage of which bond?

keep enzyme concentration constant, vary substrate concentration, and either include or exclude the inhibitor

How do you best provide data to see the effect of a competitive inhibitor on the Vmax and apparent Km of the reaction?

Km increased, Vmax unaffected

Effect of competitive inhibitor

D

one letter abbreviation for aspartate

128 kDa

An inactive tetramer of IN is expected to have approximately what molecular weight?

110 Da

What is the average weight of an amino acid?

approximately 32 kDa

What would be the molecular weight of 288 amino acids?

disrupts the interactions between monomers

What does a denaturing agent do in gel electrophoresis?

disrupts disulfide bonds

What does a reducing agent do in gel electrophoresis?

liver, cholesterol, gallbladder

Where is bile produced? What is a precursor of bile? Where is bile stored?

detoxify drugs

Which of the following functions is carried out by the liver: store bile, secrete glucagon, produce HCl, detoxify drugs

through alternative splicing of pre-mRNA

How are isoforms produced?

synthesize cDNA from protein X mRNA using primers overlapping exons 1 and 4, followed by gel electrophoresis and band visualization

The diagram shows the size and position of the exons (numbered) and introns (lines) of a gene that codes for hypothetical Protein X, which can exist as two isoforms (either 16 or 17 amino acid residues long). Which technique can be used to determine if a sample of cells expresses both isoforms?

does not exhibit cooperativity

What does a hill coefficient of 1 indicate?

cooperativity

What does a hill coefficient greater than 1 indicate?

noncompetitive inhibtor

Which type of inhibitor binds the enzyme and enzyme-substrate complex with the same affinity?

competitive (Vmax =, Km raised)

Noncompetitive (Lowers Vmax, Km = )

Uncompetitive (lowers Vmax and Km)

Mixed (Lowers Vmax, Km varies)

What are examples of reversible inhibition:

when binding to enzyme, when binding to enzyme-substrate complex

In mixed-type inhibition, in what situations does Km increase and decrease, respectively

glutamine

Given that the Vopc removes an amide from the side chain of the amino acid residue at position 61 in Rac via deamidation reaction, the amino residue at position 61 in Rac is most likely:

NH3

A deamidation reaction releases?

establish a PH gradient in the gel before adding samples

The method used to visualize CREB327WT in Experiment 2 must include which step, given that isoelectric focusing and autoradiography are used to detect phosphorylation as stated in the passage?

isoelectric point, establish a stable PH gradient

Isoelectric focusing separates proteins based on what? What must it do in order to carry this out?

serine, threonine, tyrosine

Which amino acids contain hydroxyl groups

from the same gene through alternative splicing, during which sections of the full transcript (both introns and exons) are spliced

How are different protein isoforms synthesized?

different protein isoforms

Different combinations of exons can produce:

CREB mRNA transcripts with different combinations of exons are generated

Which statement explains how two forms of CREB can be generated in cells?

epithelial cells

ovarian cells are what type of cells?

connective tissue cells

osteoclasts are what type of cells?

hydrophillic, soluble in blood

Characteristics of peptide hormones:

FSH does not require transport proteins to remain soluble in the bloodstream

Which statement describes a characteristic of FSH (peptide hormone)?

steroid proteins

What are hormones that must bind transport proteins?

cleave disulfide bonds

What is the purpose of a reducing agent in SDS-PAGE?

is composed of multiple subunits

Two gel electrophoresis analyses are performed on a sample of purified protein with unknown structure: SDS-PAGE (1 band appears) and SDS-PAGE under reducing conditions (2 bands appear). Which prediction about the protein is directly supported by these results? The protein:

adjacent nucleotides in DNA

What do phosphodiester bonds link?

disulfide bond, hydrogen bond, salt bridge

Which types of interactions contribute to the stabilization of the tertiary structure of a protein?

uncompetitive; uncompetitive inhibitors do not alter the slope of an LB plot, which is equal KM/Vmax

Which type of inhibitor does NOT alter the KM/Vmax ratio of an enzyme?

uncompetitive

Which inhibitors bind their target enzymes only when the substrate is first bound to the enzyme (substrate-enzyme complex)?

the substrate concentration is increased, the inhibitor concentration is increased

An enzyme is more effectively inhibited by uncompetitive inhibitors when:

unbroken stretches of hydrophobic amino acids

transmembrane helices are made up mostly of:

signal sequence domains

protein domains required for proteins that are directed toward secretory pathways

nuclear localization domain for nuclear translocation and a DNA binding domain for binding to regulatory regions of targeted genes

Nuclear proteins require:

nuclear factors for the expression of the ob gene; nuclear factors are the only elements that vary in different cells and therefore can confer both temporal and spatial regulation of the target genes

Which mechanism restricts the expression of leptin to adipocytes? Only adipocytes contain:

DNA sequences

promotors and enhancers are:

DNA sequence, nuclear factors

While different cells within an organism contain the same ______, the cells regulatory trans-acting elements, _______, are different and vary based on cell type

polar

glutamine and asparagine are both types of _____ amino acids

polar, charged

Which types of amino acids most likely interact with water molecules in the cytosol?

hydrophobic amino acids; the side chains of hydrophobic amino acids are free and most likely participate in dimerization of STAT3

Which amino acids are most likely present at the dimerization interface of STAT3 proteins?

exons of the LEPR gene; different isoforms of proteins are expressed from single genes through alternative splicing of exons of the primary transcript

The six different isoforms of LEPR are produced by using different:

isoelectric focusing, affinity chromatography

Which methods separate proteins based on their charge?

mass

SDS-PAGE separates proteins based on:

their interactions with specific ligands

affinity chromatography separates proteins based on:

Three; two molecules of NADH and one molecule of FADH2 are generated

How many molecules of reduced electron carriers are generated during conversion of alpha-ketoglutarate to oxaloacetate in the CTA?

glucose-6-phosphatase

Which enzyme is used both in gluconeogenesis and glycogenolysis?

catalyzes the final step of both gluconeogenesis and glycogenolysis

What does glucose-6-phosphatase do?

Vmax/KM

Recall: Vmax = Kcat[E]

Catalytic efficiency is measured by:

DNA polymerase (DNA amplification), DNA ligase (ligation of the cDNA to DNA vector), and reverse transcriptase (reverse transcription of RNA to cDNA)

Which enzymes are used in cDNA cloning?

hydrophobic, aromatic

Tryptophan characteristics:

hydrophobic, non-aromatic

Leucine characteristics:

glycogenolysis

Hepatic glycogen breakdown is characterized as:

gluconeogenesis

After hepatic glycogen stores are exhaused, the glucose pool must be replenished from non-carbohydrate sources, this implies the upregulation of:

lactate, oxaloacetate, alpha-ketoglutarate

After the depletion of hepatic glycogen in newborns, which compounds can be used as precursors to sustain the blood glucose level?

lactate, oxaloacetate, alpha-ketoglutarate, glycerol

What compounds are gluconeogenic precursors?

adenylate cyclase activity, PKA activity, CAMP generation

Activation of a G protein coupled receptor can lead to increased:

dissociation of a bound GDP in exchange for the GTP on the alpha subunit

Activation of a G protein promotes the:

glucagon; infusion of glucagon will result in mobilization of endogenous glucose storage thereby preventing hypoglycemia and brain injury

Exposure to high glucose levels results in elevated levels of circulating insulin which prevents mobilization of endogenous glucose storage. Infusion of which peptide hormone will most likely prevent brain injury in newborn infants exposed to high glucose levels during fetal development?

glycogen phosphorylase

Hepatic glycogen supports the basic metabolism of newborn during the first 12 hours. Activation of which enzyme would support the metabolism of newborn infants during the first 12 hours?

catalyzes the rate-limiting step in glycogen breakdown in glycogenolysis

What does glycogen phosphorylase do?

alpha (1-4) linkage linearly and a (1-6) linkage at branch point

the glucose polymer in glycogen is formed by which glycosidic bonds between glucose molecules:

phosphogluconate

Which of the following compounds is NOT a gluconeogenic precursor or substrate? lactate, glycerol, oxaloacetate, phosphogluconate

pentose phosphate pathway

What is phosphogluconate involved in?

greater levels of succinate and GTP

Increased activity of succinyl-CoA synthetase will result in:

CTA

converts succinyl-CoA into Succinate, forming GTP in the process

Succinyl-CoA synthetase is involved in which pathway? What is the reaction?

NADPH, which is used as a reductive agent in cellular respiratory processes

The pentose phosphate pathway results in the generation of:

free-radical scavenger

N-acetyl cysteine is most likely a:

pyruvate dehydrogenase

Lipoic acid is a cofactor for which enzyme?

pyruvate to acetyl-CoA

Pyruvate dehydrogenase is involved with the catalysis of:

pyruvate to acetyl-CoA

Treatment of cells with C75 results in lower levels of lipoic acid cofactor. Which metabolic reaction is most likely affected by treatment of cells with C75? The reaction that converts:

Uses free energy from redox reactions to pump protons from the mitochondrial matrix to the intermembrane space to generate an electrochemical gradient across the inner mitochondrial membrane.

What does the electron transport chain do?

decreased levels of protons in the intermembrane space

Any event that causes dissipation of the electrochemical gradient across the inner mitochondrial membrane will result in:

fumarate

What is the intermediate compound between succinate and malate in the CTA?

citrate, isocitrate, (alpha)-ketoglutarate, succinyl-CoA, Succinate, fumarate, malate, oxaloacetate

"Can I Keep Selling Sex For Money Officer"?

List the order of citric acid cycle compounds

biosynthesis, getting rid of reactive oxygen species

NADPH is useful for;

cis-Aconitase

What enzyme catalyzes citrate to isocitrate conversion?

succinate dehydrogenase complex II

What enzyme catalyses succinate to fumarate?

fumarase

What enzyme catalyses fumarate to malate?

…

What enzyme catalyses oxaloact

citrate synthase, it is involved in the condensation of acetyl-CoA and oxaloacetate to form citrate

This enzyme catalyses the first reaction of the CTA and is involved with the condensation of acetyl-CoA and oxaloacetate:

glucose 6-phosphate dehydrogenase

In the pentose phosphate pathway, which enzyme catalyzes the production of 6-phosphogluconolactone?

catalysis of glucose-6-phosphate to 6-phosphogluconolactone in the pentose phosphate pathway

What is the function of glucose-6-phosphate dehydrogenase?

coding, mrna, template

For any given gene, the nucleotide sequence of both the ____ strand and the _____ are complementary to the sequence of the _______ strand

southern blotting

Which technique cannot be used to analyze gene expression? western blotting, northern blotting, southern blotting

detecting a particular sequence in a sample of DNA

Southern blotting is a technique used for:

electron transport

The caspase activator, cytochrome c, released during the mitochondrial apoptotic pathway primarily functions in which cellular process

phosphorylation of ADP within the ETC

Which of the following is LEAST likely to occur in a muscle fiber that is metabolizing anaerobically?

capillary density, larger numbers of mitochondria, and higher levels of oxygen-binding proteins

Slow twitch fibers are adapted for aerobic exercise which suggests that they are likely, relative to fast-twitch fibers to have increased:

a process whereby distantly related organisms independently evolve similar traits to adapt to similar needs

What is convergent evolution defined as:

The dolphin and the shark

Which of the following animal pairs best illustrates the outcome of convergent evolution? ‘ The dolphin and the shark The domestic sheep and the mountain goat The polar bear and the panda bear The light-colored and the dark-colored forms of the peppered moth

convergent evolution

independent development of similar characteristics in two or more lineages not sharing a recent common ancestor (e.g. fish and dolphins come to resemble one another physically although they belong to different classes of vertebrates)

divergent evolution

refers to the independent development of dissimilar characteristics in two or more lineages sharing a common ancestor (e.g. seals and cats are both mammals in the order Carnivora, yet they differ markedly in general appearance)

the reproductive axis

Kallman syndrome is a disease in which Gonadotropin-releasing hormone producing neurons fail to migrate from the olfactory area to the hypothalamus during embyronic development. Which endocrine axis is disrupted in individuals with Kallman syndrome?

pituitary gonadotropin (LH and FSH) secretion

What does gonadotropin-releasing hormone regulate?

helicase catalyzes the separation of the parent DNA strands at the origin of replication

Which statement correctly identifies an enzyme involved in DNA replication and describes its primary function? Ligase catalyzes the binding of DNA primers to DNA via phosphodiester bonds Primase catalyzes the replacement of RNA primer nucleotides with DNA nucleotides Helicase catalyzes the separation of the parent DNA strands at the origin of replication Topoisomerase catalyzes the joining of adjacent Okazaki fragments into a continous strand of DNA

hydrolase

Proteases possess which type of catalytic activity?

a single mRNA transcribed from a single promoter sequence upstream of the operon

The Cgr1 and Cgr2 proteins are produced from:

primary active transport (inhibits the Na+K+ ATPase)

Which type of membrane transport is directly affected by cardiac glycosides

increasing the condensation of chromatin structure and inhibiting transcription; HDACs counter the effects of histone acetyltransferases (HATs)

histone deacetylases (HDACs) change chromatin by:

removes the positive charge on histones, decreasing the interaction of N termini of histones with the negatively charged phosphate groups of DNA, ultimately resulting in greater transcription levels

What does acetylation do?

glycogen breakdown and gluconeogenesis

the production of ketone bodies by sustained fatty acid oxidation

fasting leads to: continued fasting leads to:

the sympathetic branch of the ANS only

The adrenal medulla is part of which branch(es) of the PSN

epinephrine and norepinephrine

In response to short-term stress, what does the adrenal medulla secrete?

binding of an inhibitor to a site other than the substrate binding site

Allosteric inhibition of an enzyme involves which of the following events

ATP, which directly supplies energy for many cellular processes, and NADH, which supplies energy for the ETC

Which of the following best describes the chemical energy that is derived from the Krebs cycle? Energy is produced in the forms of:

solute concentration

Osmotic pressure is directly proportional to:

lactic fermentation is induced to regenerate NAD+

What are the effects of hypoxia on energy metabolism? In hypoxia:

Increased concentration of NADH inside the cell, for glycolysis to proceed, NADH must be converted back to NAD+ through lactic acid fermentation

In hypoxia, cells increase their glycolytic energy production, and oxidative phosphorylation is attenuated in order to reduce oxygen consumption. What does this metabolic programming lead to?

glycolysis

phosphoglucose isomerase is an enzyme involved in:

interconversion of glucose-6-phosphate (G6P) and fructose-6-phosphate (F6P)

What is the function of glucose-6-phosphate isomerase in glycolysis?

I and II only; only the CCCGGG sequence within the HIF binding sequence is palindromic

Which type(s) of restriction enzyme(s) can recognize the HIF binding sequence CCCCGGGC? A restriction enzyme that has: I. a four-base recognition sequence II. a six-base recognition sequence III. an eight-base recognition sequence

Complex II (Succinate dehydrogenase)

According to the passage, the paraganglioma tumor is associated with loss of function of succinate dehydrogenase. Which component of the ETC is defective in cells from an SDH-linked paranglioma tumor?

succinyl-CoA synthetase

What enzyme makes succinate?

radioactive amino acids were located only at one end of the molecule

Assuming that protein synthesis was under way when the radioactive amino acids were added, which of the following best describes how radioactivity was distributed in one of the first molecules of Protein X that was completely translated

code for or carry a transcriptase that copies viral RNA

Certain viruses contain RNA as their genetic material. One of the ways these RNA viruses replicate themselves is to:

glomerulus; in healthy individuals, the structure of the glomerular capillaries prevents the entry of large molecules, such as proteins, into the filtrate

Large amounts of protein are found in the urine of a patient. Based on this information, which portion of the nephron is most likely malfunctioning?

37 degrees Celsius

Optimum temperature for enzymes:

D

The rate of a typical enzymatic reaction is increased by which of the following changes? A. Decrease in susbtrate concentration B. Increase in PH from 6.8 to 7.4 C. Increase in the energy of activation D. Increase in temperature from 20 degrees Celsius to 37 degrees Celsius

epithelial

Mucous secretions in the respiratory tract inhibit microbial infections. These secretions are produced by which of the following tissue types found in the lungs?

epithelial cells

specialized cells for secretion that are present in the respiratory tract

monoamine oxidase A

This enzyme is involved in the oxidation and degradation of serotonin. A drug that inhibits the activity of this enzyme could thus be used to relieve depression.

amount of time that serotonin is present in the synaptic space

SSRIs most likely relieve depression by increasing the:

a decrease in the surface area of the small intestine, leading to a decrease in nutrient absorption

Intestinal villi atrophy could result in:

increase the intestinal surface area available for absorption for nutrient absorption in the lumen

What is the function of villi in the small intestine?

decrease, resulting in an increase of fluid in the body tissues

One consequence of advanced malnutrition is reduced amounts of plasma proteins in the blood. This condition would most likely cause the osmotic pressure of the blood to:

plasma protein

albumin is a type of:

Plasma proteins in the blood increase the osmotic pressure of the blood, which in turn, increases the return of fluid to the circulatory system from the body tissues

What is the function/purpose of large plasma proteins, such as albumin, in the blood?

They increase the osmotic pressure within the intestines, leading to diarrhea due to excess unabsorbed fats inhibiting normal water and electrolyte absorption

Within the intestines, unabsorbed fats are broken down into fatty acids by intestinal bacteria. Given this, excess unabsorbed fats most likely have which of the following effects within the intestines?

osteoblast, osteoclast

To increase calcium levels in the blood, _____ activity should be decreased and _____ activity should be increased to release stored calcium from the bone to the bloodstream

decrease osteoblast activity, and increase osteoclast activity

The most effective way for the body to utilize bone tissue to increase blood calcium levels would be to simultaneously:

Bowman’s capsule –> proximal tubule –> loop of Henle –> distal tubule –> collecting duct

Order in which filtrate passes through the tubular regions of a nephron:

diluting segment

what is the only portion of the nephron that can produce urine that is more dilute than the blood

No; action potentials result in an increased permeability of the plasma membrane to sodium

A student postulated that the sodium pump directly causes action potentials along neurons. Is this hypothesis reasonable?

2

Glycolysis produces how many ATP molecules per glucose molecule

genetic mutations occur in proliferating somatic cells

H. pylori infection may cause increased proliferation of mucosal cells in the stomach. This may lead to gastric cancer if:

the movement of leukocytes into mucosal tissue; leukocytes gravitate toward an inflammation

According to the passage, the cagA gene leads to inflammation and may be related to the genesis of gastric cancer. Therefore, it can be assumed that the cagA gene product will cause:

glucose molecules raise the osmotic pressure of the extracellular space

Hyperglycemia promotes cellular dehydration because:

blood plasma, lymph

Which of these options would be considered part of the extracellular fluid: I. cytoplasm II. Blood plasma III. Lymph

glycolysis

List one way that metabolic pathways can produce energy without using oxygen:

decrease in plasma protein level

in starvation when the body is forced to use albumin as an energy source

What could be attributed as a cause of edema, an increase of fluid in body tissues? In what situations could this occur?

No, aldosterone causes Na+ reabsorption by kidney tubules; ingestion of excessive NaCl would trigger Na+ secretion into the urine

Would an increase in the level of plasma aldosterone be expected to follow ingestion of excessive quantities of NaCl?

mitosis

The liver is different from many other organs in that it can at least partially regenerate following illness or damage. This regeneration is accomplished primarily through:

the process whereby human body cells (not gametes) reproduce

What is mitosis?

the ability to produce ATP via ATP synthase

Most bacterial cells and human cells are alike in:

plasma membrane of bacteria, inner mitochondrial membrane in human cells

Both bacterial and human cells have the capacity to produce ATP via ATP synthase, ATP synthesis takes place where on the bacteria and in human cells, respectively?

although the chemical composition of prokaryotic and eukaryotic ribosomes is similar, it is distinct enough that several types of antibiotics are able to preferentially target prokaryotic ribosomes over eukaryotic ribosomes

Describe the chemical similarity between bacterial and eukaryotic ribosomes

The activated form of vitamin D stimulates the absorption of calcium into the blood

Why do calcium supplements often include vitamin D

Activated vitamin D acts on the small intestine to stimulate the absorption of calcium into the bloodstream

What organelle does vitamin D act on? What does this stimulate?

osteoclast activity, parathyroid hormone

A low level of calcium in the plasma will trigger an increase of:

Bone reabsorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood. Calcitonin reduces bone resorption.

What is bone resorption?

removal of the parathyroid gland would lead to hypocalcemia, which would cause increased neuromuscular excitability because of the change in membrane potential

What would be the result of complete removal of the parathyroid glands?

the ability to successfully breed and produce fertile offspring

What is a key factor that determines a species:

decreased volume and decreased pressure

aldosterone stimulates sodium reabsorption by the kidneys. What changes in blood volume and pressure would be expected as a result of aldosterone deficiency?

water passively follows sodium during reabsorption in the kidney, thus less sodium reabsorption would result in less water reabsorption into the bloodstream, resulting in decreased blood volume

Why would decreased sodium reabsorption into the bloodstream result in decreased volume?

hypothalamus-pituitary-ovary

The sequence of events in the human menstrual cycle involves close interaction among which organs?

3:1; the double stranded daughter DNA molecule would be an exact duplicate of the parent molecule. It would have the same (A + T)/(G + C) ratio

DNA polymerase catalyzes the replication of chromosomal DNA in bacteria. A double-stranded DNA molecule contains bases with a ratio of (A+T)/(G+C) = 3:1. This molecule is replicated with DNA polymerase in the presence of the four deoxynucleside triphosphates with a molar ratior of (A+T)/(G+C)=1:2. What is the expected ratio of (A+T)/(C+G) in the double-stranded daughter DNA molecule?

the nucleus

In which organelle of a eukaryotic cell is the pyrimidine uracil, as part of uridine triphosphate (UTP), incorporated into nucleic acid

mesoderm, ectoderm

Where does the dermis (dermal tissue derive from? Where does the epidermis derive from?

nervous tissue, dermal is from the mesoderm whereas epidermis is from the ectoderm

Of the following tissues, which is NOT derived from embryonic mesoderm? Circulatory Bone Dermal Nerve

relaxation of the diaphragm

All of the following occur during normal inspiration of air in mammals EXCEPT: elevation of the rib cage relaxation of the diaphragm reduction of pressure in the pleural cavity contraction of the external intercostal rib muscles

elevation of the rib cage, reduction of pressure in the pleural cavity, contraction of the external intercostal rib muscles

List three things that occur during inspiration:

the diaphragm contracts and pulls downward, causing air to enter the lungs

What causes air to enter the lungs in inspiration?

volume of a breath that does not participate in gas exchange

What is the respiratory dead space?

6,500 mL; 800 mL – 150 mL = 650 mL X 10 = 6500 mL

Assuming that the breathing rate is 10 breaths/min, the tidal volume is 800 mL/breath, and the nonalveolar respiratory system volume (dead space) is 150 mL, what is the net volume of fresh air that enters the alveoli each minute?

colon (large intestine)

E. coli bacteria is a species common to which part of the gastrointestinal tract?

colon

The appendix is continuous with which gastrointestinal tract?

abdominal cavity

When the appendix ruptures, contents of the colon as well as infective agents such as E. coli, will spill over to the:

True

The sympathetic nervous system does not directly affect the activity of the digestive enzymes. True or false.

peristalsis, secretion of digestive enzymes

The sympathetic system directly inhibits:

Enzymatic breakdown of food molecules

Which of the following processes is LEAST directly influenced by adrenergic drugs (mimic activation of the sympathetic nervous system)? Peristalsis Secretion of digestive enzymes Enzymatic breakdown of food molecules Nutrient delivery to muscles and organs

passive H2O diffusion along a concentration gradient

The osmotic concentration of plasma proteins in the venous side of capillaries helps reduce the amount of interstitial fluid in tissues by inducing:

arteries —> capillaries –> veins

What is the order of blood flow?

net fluid flow in the direction of interstitial spaces will increase

Capillaries in the kidney and elsewhere in the body maintain fluid homeostasis by balancing hydrostatic and osmotic pressures. Which of the following is the initial effect of a blood clot forming on the venous side of a capillary bed?

capillaries, hydrostatic pressure would build up in the capillaries and net fluid flow into the interstitial spaces would increase

If blood flow is blocked at the venous side, where would blood start to accumulate? What would increase as a result?

A tissue culture; viruses take advantage of the elaborate intracellular mechanisms of the host cell using them to make more virus particles. To do this they need intact host cells.

Which of the following media would most likely be used to grow virions in the laboratory? A suspension of ribosomes and ATP A suspension of human DNA A nutrient broth A tissue culture

translation of viral nucleic acid

Most viral proteins are produced directly by:

periodic menstruation will resume

Postmenopausal women receiving estrogen and progesterone therapy will most likely experience which of the following side effects?

estrogen, progesterone

What hormones are actively secreted by the ovaries in pre-menopausal women which act to maintain the uterine cycle

decreased osteoblast and increased osteoclast activity

Osteoblasts, which form bone, and osteoclasts, which resorb it, work together to cause continous bone remodeling. In a person suffering from osteoporosis, which of the following combinations of changes in the activity of these cell types will most likely occur?

spermatozoon/spermatozoa

The cell type in the male reproductive system that is most analogous to the female ovum is the:

female gamete that has completed meiosis and contains the haploid number of maternally derived chromosomes

What is the mature ovum defined as?

the mature male gametes that contain the haploid number of paternally derived chromosomes

What is the spermatozoa?

back-mutated and regained the ability to synthesize their own histidine due to exposure to the mutagen

The survival of Salmonella on histidine-deficient media suggest that the strains have:

S phase; DNA replication occurs during the S or synthesis phase of a cell cycle

If an anti-inflammatory drug interfered with DNA replication, in which phase of the cell cycle would cells tend to be arrested?

PO2 would increase and PCO2 would decrease

If an artery that supplies blood to a lung lobe was blocked but ventilation to the lobe was unaffected, how would alveolar gas partial pressures change

The splitting of centromeres

In mammals, which of the following events occurs during mitosis but does NOT occur during meiosis I?

homologous pairs of chromosomes are separated into the two daughter cells

What occurs during anaphase I of meiosis I?

respiration

All of the following are functions of mammalian skin EXCEPT: sensation respiration protection from disease protection against internal injury

touch sensation, protection from disease, protection against internal injury

Functions of mammalian skin:

true

In mammals, skin is not responsible for exchanging oxygen and CO2 with the environment, true or false.

incidence of expression of deleterious recessive traits

Inbreeding can reduce the fitness of a population in the short term because it causes an increase in the:

incidence of expression of deleterious recessive traits

Inbreeding can reduce the fitness of a population in the short term because it causes an increase in the:

influx of tissue fluid into the bloodstream

An intravenous infusion causes a sharp rise in the serum level of albumin (the major osmoregulatory protein in the blood). This will most likely cause an:

cartilaginous areas in the long bones; long bones grow via endochondral ossification, which requires cartilaginous growth plates at the ends of long bones, that thicken as cartilage and later become ossified

When viewing an X-ray of the bones of a leg, a doctor can tell if the patient is a growing child, because the X-ray shows:

fully ossified adult bones

dividing bone cells and haversion canals can be present in:

negative pressure pumping action

inflation of the lungs in mammals is accomplished by:

bridges between actin and muosin form, break, and re-form, leading to a shortening of muscle sarcomeres

Which statement below most accurately describes the roles of the proteins actin and myosin during muscular contraction?

self-replicating

In the macronucleus, the genes for rRNA are located extrachromosomally. This suggests that the rRNA genes are:

nucleotides; guanosine tri-phosphate is a nucleotide

The Arf1-activating molecule GTP is most closely related to which family of biomolecules

phosphatase (e.g. GAP)

a class of hydrolase responsible for the cleavage of phosphate bonds utilizing water to remove a molecule of PI

because the antibody was generated in the mouse, repeated usage in the same patient would elicit the production of human anti-mouse properties

The scientists wanted to use antibody B clinically (to treat humans), but this proposal was rejected. Which of the following is the most logical reason for the rejection?

DNA –> mRNA

The cutting of introns and the splicing associated with the expression of the factor VIII gene occur during which of the following steps in the protein-synthesis process?

lack a mechanism for splicing out introns

Recombinant DNA technology allows scientists to mass-produce some human proteins by transferring human genes into bacteria. The characteristics of bacteria that would most likely prevent factor VIII from being produced in this way is that bacteria:

a 1-electron carrier

In oxidative phosphorylation, cytochome c acts as:

The digestive enzymes for the polysaccharide had to be transcribed and translated

The figure below shows a population growth curve for a bacterial colony before and after the addition of a polysaccharide, which explains why the bacterial colony did NOT grow immediately after the polysaccharide was added?

visual receptor cells in the retina; photoreceptors, are visual receptors in the retina which absorb light

The pigments for red-color blindness will affect production of proteins in which of the following types of cells?

acetyl-CoA; in the absence of oxygen, pyruvate is converted to lactate in the cytoplasm and is not transported to the mitochondria to be converted to acetyl-CoA

When a striated muscle cell metabolizes glucose in the complete absence of O2, which of the following substances is NOT produced in a significant amount?

a carboxyl group

A fatty acid is composed of a long hydrocarbon tail and a head consisting of: