Quiz 3

Question 1

A cell is equilibrated in an aqueous solution of 150 mmol/L sodium chloride. Which of the following best descries what will happen to cell volume when the cell is placed in an aqueous solution of 300 mmol/L glycerol?

Answer 1

Increase

Question 2

Human red blood cells (RBCs) placed in a solution of 300 mOsm/L glycerol will swell and burst. However, rabbit RBCs placed in 300 mOsm/L glycerol neither swell nor shrink. This difference between human and rabbit RBCs occurs even when both cell types are equilibrated in isontonic saline (300 mOsm/L NaCl) before placement in the glycerol. Based on this information, which of the following can be concluded about a 300 mOsm/L solution of glycerol for the different cell types?

Answer 2

Rabbit: Isotonic and isosmotic
Human: Hypotonic and isosmotic

Question 3

The diagram illlustrates possible changes in red blood cell volume resulting from a change in extracellular fluid compositin for a cell equilibrated in a 150 mmol/L solution of sodium chloride (NaCl) at time 0. Whihc curve best illustrates the volume change caused by immersion of the cell in an aqueous solution of 200 mmol/L NaCl, 100 mmol/L glycerol? Hint: NaCl can be assumed that has zero permeability through the cell membrane whereas glycerol is quite permeable

Answer 3

Decreases at a decreasing rate. (concave up)

Question 4

The diagram illlustrates possible changes in red blood cell volume resulting from a change in extracellular fluid compositin for a cell equilibrated in a 150 mmol/L solution of sodium chloride (NaCl) at time 0. Which curve best illustrates the volume change caused by immersion of the cell in an aqueous solution of 150 mmol/L CaCl2, 100 mmol/L glycerol? Hint: Use the previous graph . CaCl2 can be assumed that has zero permeability through the cell membrane whereas glycerol is quite permeable

Answer 4

Decreases at a decreasing rate. (concave up)

Question 5

Typically, cancer is the result of a single mutation within a cell

Answer 5

false

Question 6

Tumor cells rely on glycolysis rather than oxidative phosphorylation because they have no mitochrondria

Answer 6

false

Question 7

what is the fastest rate that cancer cells can divide?

Answer 7

about 10-20 hours

Question 8

electrochemical gradients are:

Answer 8

-the driving force for non ion movement across membranes.
-due to concentration differences across a cell membrane.
-due to potential differences across a cell membrane.

Question 9

which ion(s) are most important for establishing the normal resting membrane potential of a neuron?

Answer 9

K+ and Na+

Question 10

action potentials:

Answer 10

-conduct neural signs along the membrane.
-are an all-or-none phenomenon

Question 11

which of the following statements about myelination are true?

Answer 11

-in general, meyelinated axons transmit signals faster than unmeyelinated axons.
-myelinatenation enables salatory conduction

Question 12

which of the following statements about the absolute refractory period are true?

Answer 12

-the absolute refractory period occurs when the inactivation gates of the voltage-gated sodium channels are closed.