Chp 3 Quiz

Which of the following describes the plasma membrane?
a single-layered membrane that surrounds the nucleus of the cell
a membrane composed of tiny shelves or cristae
a double layer of protein enclosing the plasma
the phospholipid bilayer surrounding the cell

the phospholipid bilayer surrounding the cell

Which type of cell junction acts as anchors and distributes tension through a cellular sheet and reduces the chance of tearing when it is subjected to great mechanical stress?
tight junctions
connexons
gap junctions
desmosomes

desmosomes

Which of the following is a function of a plasma membrane protein?
circulating antibody
molecular transport through the membrane
oxygen transport
forms a lipid bilayer

molecular transport through the membrane

Which of the following would not be a constituent of a plasma membrane?
messenger RNA
phospholipids
glycoproteins
glycolipids

messenger RNA

Which of the following is not a factor that binds cells together?
special membrane junctions
glycoproteins in the glycocalyx
wavy contours of the membranes of adjacent cells
glycolipids in the glycocalyx

glycolipids in the glycocalyx

Which of the following is a principle of the fluid mosaic model of cell membrane structure?
The lipid bilayer is a solid at body temperature, thus protecting the cell.
Phospholipids consist of a polar head and a nonpolar tail made of three fatty acid chains.
Phospholipids form a bilayer that is largely impermeable to water-soluble molecules.
All proteins associated with the cell membrane are contained in a fluid layer on the outside of the cell.

Phospholipids form a bilayer that is largely impermeable to water-soluble molecules.

The glycocalyx is often referred to as the "cell coat," which is somewhat fuzzy and sticky with numerous cholesterol chains sticking out from the surface of the cell membrane.
True
False

False

Your patient has the flu and reports 5 to 6 loose stools a day. He has experienced an isotonic fluid volume loss. What does "isotonic fluid loss" mean?
More water is lost than enters the body.
No water is lost: the body water content remains the same.
Water and electrolytes are lost in equal proportions.
Less water is lost than enters the body.
Water is lost at the same rate as it enters the body.

Water and electrolytes are lost in equal proportions.

A red blood cell placed in pure water would ________.
neither shrink nor swell
swell initially, then shrink as equilibrium is reached
swell and burst
shrink

swell and burst

Which of these is not a function of the plasma membrane?
It prevents potassium ions from leaking out and sodium ions from crossing into the cell.
It encloses the cell contents in such a way that water I the body is divided into separate compartments.
It acts as a site of cell-to-cell interaction and recognition.
It is selectively permeable but permits water and gases to cross.

It prevents potassium ions from leaking out and sodium ions from crossing into the cell.

Which of the following statements is correct regarding net diffusion?
Molecular weight of a substance does not affect the rate.
The lower the temperature, the faster the rate.
The greater the concentration gradient, the faster the rate.
The rate is independent of temperature.

The greater the concentration gradient, the faster the rate.

If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen?
The cells will show no change due to diffusion of both solute and solvent.
The cells will shrink at first, but will later reach equilibrium with the surrounding solution and return to their original condition.
The cells will lose water and shrink.
The cells will swell and ultimately burst.

The cells will lose water and shrink.

Which transport process is the main mechanism for the movement of most macromolecules by body cells?
secondary active transport
phagocytosis
pinocytosis
receptor-mediated endocytosis

receptor-mediated endocytosis

In osmosis, movement of water occurs toward the solution with the lower solute concentration. True
False

False

A process by which large particles may be taken into the cell for food, protection of the body, or for disposing of old or dead cells is called phagocytosis.
True
False

True

Facilitated diffusion always requires a carrier protein.
True
False

True

In their resting state, all body cells exhibit a resting membrane potential ranging from -50 to about +50 millivolts.
True
False

False

Which of the following is NOT a function of the smooth endoplasmic reticulum?
lipid metabolism and cholesterol synthesis
protein synthesis in conjunction with ribosomes
breakdown of stored glycogen to form free glucose
steroid-based hormone synthesis

protein synthesis in conjunction with ribosomes

Which of the following is NOT a role of cell adhesion molecules:
anchor cells to molecules in the extracellular space and to each other
initiators of cell-to-cell signaling for muscle contraction
transmitters of intracellular signals that direct cell migration, proliferation, and specialization
mechanical sensors

initiators of cell-to-cell signaling for muscle contraction

Which of the following statements is most correct regarding the intracellular chemical signals known as "second messengers"?
Second messengers act through receptors called K-proteins.
Second messengers usually act to remove nitric oxide (NO) from the cell.
Second messengers usually inactivate protein kinase enzymes.
Cyclic AMP and calcium may be second messengers.

Cyclic AMP and calcium may be second messengers.

Your patient has a respiratory disease that has literally paralyzed the cilia. Why would this patient be at an increased risk for a respiratory infection?
The patient would not be at an increased risk of respiratory infection.
If cilia are paralyzed then the cells of the respiratory system cannot phagocytose the particles, including bacteria; these bacteria will remain in the lungs and may cause a respiratory infection.
If cilia are paralyzed then the particles, including bacteria, cannot be moved to the bottom of the lungs and cannot be phagocytosed by the cells in the lungs; bacteria remain in the lungs and may cause a respiratory infection.
If cilia are paralyzed then the phagocytosed particles, including bacteria, cannot be moved to fuse with the lysosomes for destruction; the bacteria will remain in the cells and may cause a respiratory infection.
If cilia are paralyzed then mucus-containing particles, including bacteria, will remain in the lungs and may cause a respiratory infection.

If cilia are paralyzed then mucus-containing particles, including bacteria, will remain in the lungs and may cause a respiratory infection.

Site of synbthesis of lipis and steroid molecules

endoplasmic reticulmum

Produces ATP aerobically

mitochondrion

Site of enzymatic breakdown of phagocytized material.

lysosomes

Forms the mitotic spindle

centroiles

Package proteins for insertion in the cell membrane or exocytosis

golgi apparatus

Source of cell autolysis

lysosomes

replicate for cell division

centroiles

In certain kinds of muscle cells, calcium ions are stored in ________.
the smooth ER
the cytoplasm
the rough ER
both smooth and rough ER

the smooth ER

Which of these is an inclusion, not an organelle?
cilia
lysosome
melanin
microtubule

melanin

Mitochondria ________.
synthesize proteins for use outside the cell
are always the same shape
are single-membrane structures involved in the breakdown of ATP
contain some of the DNA and RNA code necessary for their own function

contain some of the DNA and RNA code necessary for their own function

Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. This statement is ________.
false; proteins thus manufactured are for use inside the cell only
true
false; lipids, not proteins, are synthesized this way
false; integral cell membrane proteins are also synthesized this way

false; integral cell membrane proteins are also synthesized this way

Microfilaments are thin strands of the contractile protein myosin.
True
False

False

Interstitial fluid represents one type of extracellular material.
True
False

True

There is only one cell type in the human body that has a flagellum.
True
False

True