Deck 3: Cell Structure and Function

Question 1

Carbon dioxide is produced from $\beta$ -oxidation of fats.

Answer 1

False

Question 2

The human genome contains about 30,000 genes.

Answer 2

False

Question 3

An increase in extracellular potassium ion from 4.0 to 6.0 mEq/L would

A) hyperpolarize the resting membrane potential.
B) make it more difficult to reach threshold and produce an action potential.
C) hypopolarize the resting membrane potential.
D) alter the threshold potential.

Answer 3

hypopolarize the resting membrane potential.

Question 4

Ion channels cannot transport ions against an electrochemical gradient.

Question 5

Glycolysis produces two ATP molecules per glucose molecule.

Question 6

The lipid bilayer of the plasma membrane has low permeability to charged and polar molecules.

Question 7

Excitable cells are able to conduct action potentials because they have

A) receptors for neurotransmitters.
B) gap junctions.
C) ligand-gated channels.
D) voltage-gated channels.

Question 8

GTP-binding proteins (G proteins) function to

A) activate receptors on the extracellular surface.
B) degrade second-messenger molecules.
C) activate intracellular enzyme systems.
D) synthesize ATP.

Question 9

Which of the following reactions would occur in the body spontaneously without energy input from direct (ATP) or secondary (gradient) energy sources?

A) Sodium entry into the cell
B) Calcium extrusion from the cell
C) Translation
D) Endocytosis/exocytosis

Question 10

Proteins made on the rough endoplasmic reticulum are transported to the cell's cytoplasm.

Question 11

The primary purpose of glycolysis is to

A) produce ATP.
B) supply substrate to the Krebs cycle.
C) produce energy.
D) supply lactate during anaerobic conditions.

Question 12

Glycolysis is the metabolic process of breaking down a glucose molecule to form

A) CO₂ and H₂O.
B) 2 ATP and 2 pyruvate.
C) 34 ATP.
D) oxygen and ATP.

Question 13

Repolarization of a neuron after a depolarizing action potential is due to

A) activation of the Na⁺-K⁺ pump.
B) opening of voltage-gated calcium channels.
C) efflux of potassium.
D) extrusion of calcium.

Question 14

The energy derived from the transport of electrons along the electron transport chain on the inner mitochondrial membrane is used to

A) synthesize ATP.
B) generate a proton (H⁺) gradient.
C) reduce oxygen to water.
D) produce NADH.

Question 15

The resting membrane potential in nerve and skeletal muscle is determined primarily by

A) extracellular sodium ion concentration.
B) the ratio of intracellular to extracellular potassium ions.
C) activation of voltage-gated sodium channels.
D) activity of energy-dependent membrane pumps.

Question 16

Each molecule of O₂ accepts four electrons from the mitochondrial electron transport chain to form two H₂O.

Question 17

Diffusion and osmosis occur passively.

Question 18

Approximately 90% of the cell membrane is composed of protein, and 10% is lipid.

Question 19

The four nucleotide bases that form DNA are C, G, A, and T.

Question 20

Activation of the enzyme adenylyl cyclase by a stimulatory G protein results in the formation of

A) phosphodiesterase.
B) ATP.
C) cGMP.
D) cAMP.

Question 21

Match the following terms with the descriptions below (not all letters will be used).
Processes and "addresses" proteins for export

A)Actin
B)Microtubules
C)Cytoskeleton
D)Rough endoplasmic reticulum
E)Mitochondria
F)Peroxisomes
G)Lysosomes
H)Golgi apparatus
I)Smooth endoplasmic reticulum

Question 22

Phospholipids spontaneously form lipid bilayers because they are

A) polar.
B) charged.
C) insoluble.
D) amphipathic.

Question 23

Match the following terms with the descriptions below (not all letters will be used).
Mediate the movement of chromatids during mitosis

A)Actin
B)Microtubules
C)Cytoskeleton
D)Rough endoplasmic reticulum
E)Mitochondria
F)Peroxisomes
G)Lysosomes
H)Golgi apparatus
I)Smooth endoplasmic reticulum

Question 24

Binding of a ligand to a type of G-protein-linked receptor called G_s stimulates the production of

A) cAMP.
B) cGMP.
C) IP₃.
D) DAG.

Question 25

Cell-to-cell communication through secretion of chemical signals into the extracellular fluid between them is called _____ signaling.

A) neurocrine
B) paracrine
C) endocrine
D) autocrine

Question 26

Match the following terms with the descriptions below (not all letters will be used).
Contains Krebs cycle enzymes in its matrix

A)Actin
B)Microtubules
C)Cytoskeleton
D)Rough endoplasmic reticulum
E)Mitochondria
F)Peroxisomes
G)Lysosomes
H)Golgi apparatus
I)Smooth endoplasmic reticulum

Question 27

Match the following terms with the descriptions below (not all letters will be used).
Contains digestive enzymes of the hydrolytic sort

A)Actin
B)Microtubules
C)Cytoskeleton
D)Rough endoplasmic reticulum
E)Mitochondria
F)Peroxisomes
G)Lysosomes
H)Golgi apparatus
I)Smooth endoplasmic reticulum

Question 28

Match the following terms with the descriptions below (not all letters will be used).
Transmits information about cell configuration to the nucleus

A)Actin
B)Microtubules
C)Cytoskeleton
D)Rough endoplasmic reticulum
E)Mitochondria
F)Peroxisomes
G)Lysosomes
H)Golgi apparatus
I)Smooth endoplasmic reticulum

Question 29

Enzymes function to

A) reverse the direction of reactions.
B) control the amount of products made.
C) increase the rate of reactions.
D) provide the energy to drive reactions.

Question 30

Ion channels are triggered to open or close by all of the following mechanisms except

A) mechanical stretch.
B) change in membrane voltage.
C) hydrolysis of ATP.
D) binding to a chemical ligand.