Question 1

Which of these statements is correct for ATP synthase?

Accepted Answer

A) It transports hydrogen ions from the matrix to the intermembrane space of the mitochondrion. 
B) It is activated by the flow of hydrogen ions from the intermembrane space to the matrix. 
C)  It enzymatically converts ATP to ADP. 
D)  It yields two molecules of ATP.

Question 2

If a typical body cell is placed in a 5 percent saline solution, what will happen to the cell?

Accepted Answer

A) It will fill with water. 
B) It will lyse. 
C)  It will lose water. 
D)  It will remain unchanged.

Question 3

Which of the following occurs when chemically gated Na+ channels open?

Accepted Answer

A) The membrane hyperpolarizes. 
B) The membrane repolarizes. 
C)  The membrane depolarizes. 
D)  The membrane becomes more negative.

Question 4

An unmyelinated fibre with a large diameter can conduct action potentials more rapidly than an unmyelinated fibre with a smaller diameter.

Accepted Answer

A) True 
 B)False

Question 5

Under an electron microscope, the plasma membrane appears as a trilaminar structure consisting of two dark layers separated by a light middle layer.

Accepted Answer

A) True 
 B)False

Question 6

Which of these statements correctly describes what happens when "temporal summation" takes place?

Accepted Answer

A) Two EPSPs from the same presynaptic input occur so closely together in time that they add together, or sum. 
B) An EPSP and an IPSP occur simultaneously and cancel each other out. 
C)  Two EPSPs that occur simultaneously from different presynaptic inputs add together, or sum. 
D)  Action potentials occurring in two presynaptic inputs simultaneously converge upon the postsynaptic cell, initiating two different action potentials in the postsynaptic cell.

Question 7

Movement of K+ into the cell requires energy expenditure, whereas movement of Na+ into the cell does not.

Accepted Answer

A) True 
 B)False

Question 8

An action potential in a presynaptic neuron induces opening of voltage-gated ____________________ channels in the synaptic knob, which triggers exocytosis of synaptic vesicles.

Accepted Answer

The answer of An action potential in a presynaptic neuron...

Question 9

Which of the following is known to be second messengers?

Accepted Answer

A) cyclic AMP 
B) potassium 
C)  ATP 
D)  hormone

Question 10

Match the terms, labelled a. through d., to their descriptions. (Options may be used more than once or not at all.)
a.microtubules
b.microfilaments
c.intermediate filaments
d.micro trabecular lattice
-play(s) a key role in muscle contraction

Accepted Answer

The answer of Match the terms, labelled a. through d.,...

Question 11

Which of the following statements correct describes IPSP?

Accepted Answer

A) It is produced by increased Na+ permeability and K+ permeability. 
B) It is produced by increased K+ permeability or increased Cl- permeability. 
C)  It is a small depolarization of the postsynaptic neuron. 
D)  It is produced by increased Na+ permeability only.

Question 12

In active transport, a substance moves from an area of ____________________ concentration to an area of ____________________ concentration.

Accepted Answer

The answer of In active transport, a substance moves from...

Question 13

Match the terms, labelled a. through f., to their correct descriptions. (Options may be used more than once or not at all.)
a.plasma membrane
b.nucleus
c.cytoplasm
d.cytosol
e.organelles
f.cytoskeleton
-highly organized membrane-bound intracellular structures

Accepted Answer

The answer of Match the terms, labelled a. through f.,...

Question 14

If presynaptic neuron Z is repeatedly stimulated very rapidly, what change would you expect to occur in the postsynaptic neuron?

Accepted Answer

A) a single EPSP 
B) a single IPSP 
C)  temporal summation of EPSPs 
D)  spatial summation of EPSPs

Question 15

Assume a hypothetical postsynaptic neuron has three presynaptic inputs, X, Y, and Z. When presynaptic neurons X and Y are stimulated simultaneously, the postsynaptic neuron reaches threshold and undergoes an action potential; yet, when presynaptic neurons X and Z are stimulated simultaneously, there is no change in potential of the postsynaptic neuron. Which of these statements correctly describes the presynaptic neurons Y and Z?

Accepted Answer

A) Presynaptic neurons Y and Z are both excitatory. 
B) Presynaptic neurons Y and Z are both inhibitory. 
C)  Presynaptic neuron Y is excitatory, and presynaptic neuron Z is inhibitory. 
D)  Presynaptic neuron Y is inhibitory, and presynaptic neuron Z is excitatory.

Question 16

At the end of repolarization, the newly opened channels for ____________________ ions close.

Accepted Answer

The answer of At the end of repolarization, the newly...

Question 17

Presynaptic facilitation results from which of the following?

Accepted Answer

A) alteration of calcium permeability 
B) continued EPSP generations 
C)  neuromodulator effects 
D)  increased neurotransmitter production

Question 18

With secondary active transport, the movement of __________________.

Accepted Answer

A) Na+ into the cell by the cotransport carrier is downhill 
B) Na+ into the cell by the cotransport carrier is uphill 
C)  glucose by the cotransport carrier is uphill 
D)  Cl- into the cell by the cotransport carrier is downhill

Question 19

Which of the following applies to lysosomes?

Accepted Answer

A) They contain powerful hydrolytic enzymes. 
B) They generate hydrogen peroxide. 
C)  They facilitate intracellular reactions. 
D)  They store excess nutrients

Question 20

The extracellular matrix and the local cells that secrete it are collectively known as connective tissue.

Accepted Answer

A) True 
 B)False

Exam 2: Cell Physiology

Which of these statements is correct for ATP synthase?

If a typical body cell is placed in a 5 percent saline solution, what will happen to the cell?

Which of the following occurs when chemically gated Na⁺ channels open?

An unmyelinated fibre with a large diameter can conduct action potentials more rapidly than an unmyelinated fibre with a smaller diameter.

Under an electron microscope, the plasma membrane appears as a trilaminar structure consisting of two dark layers separated by a light middle layer.

Which of these statements correctly describes what happens when "temporal summation" takes place?

Movement of K⁺ into the cell requires energy expenditure, whereas movement of Na⁺ into the cell does not.

An action potential in a presynaptic neuron induces opening of voltage-gated ____________________ channels in the synaptic knob, which triggers exocytosis of synaptic vesicles.

Which of the following is known to be second messengers?

Match the terms, labelled a. through d., to their descriptions. (Options may be used more than once or not at all.) a.microtubules b.microfilaments c.intermediate filaments d.micro trabecular lattice -play(s) a key role in muscle contraction

Which of the following statements correct describes IPSP?

In active transport, a substance moves from an area of concentration to an area of concentration.

Match the terms, labelled a. through f., to their correct descriptions. (Options may be used more than once or not at all.) a.plasma membrane b.nucleus c.cytoplasm d.cytosol e.organelles f.cytoskeleton -highly organized membrane-bound intracellular structures

If presynaptic neuron Z is repeatedly stimulated very rapidly, what change would you expect to occur in the postsynaptic neuron?

At the end of repolarization, the newly opened channels for ____________________ ions close.

Presynaptic facilitation results from which of the following?

With secondary active transport, the movement of __________________.

Which of the following applies to lysosomes?

The extracellular matrix and the local cells that secrete it are collectively known as connective tissue.