Question 1

Which of the following best describes the structure of a biological membrane according to the fluid mosaic model?

Accepted Answer

Protein molecules embedded in a dynamic bilayer of phospholipids.

Question 2

Which of the following is NOT a function of membrane proteins?

Accepted Answer

Synthesizing proteins.

Question 3

A molecule moves down its concentration gradient when it goes from an area of:

Accepted Answer

High to low concentration.

Question 4

Which molecule most easily diffuses across a biological membrane’s lipid bilayer, without help of a protein?

Accepted Answer

O2

Question 5

Which process is also called the process of cell 'eating'?

Accepted Answer

Phagocytosis

Question 6

Passive membrane transport processes include:

Accepted Answer

Movement of a substance down its concentration gradient.

Question 7

A transport protein that simultaneously transports two different molecules in different directions is called:

Accepted Answer

An antiporter.

Question 8

Osmosis is best defined as the movement of:

Accepted Answer

Water molecules across a semi-permeable membrane into a region of high solute concentration.

Question 9

Plants become turgid when placed in this type of solution:

Accepted Answer

Hypotonic.

Question 10

Which of the following processes includes all of the others?

Accepted Answer

Passive transport.

Question 11

Which type(s) of molecules cannot enter/exit the cell via simple diffusion and require facilitated diffusion?

Accepted Answer

b and e only.

Question 12

The force driving simple diffusion is $$a\ concentration\ gradient$$, while the energy source for active transport is:

Accepted Answer

$$ATP\ hydrolysis$$

Question 13

A sodium-potassium pump:

Accepted Answer

Transports 3 sodium ions out of a cell and 2 potassium ions into a cell using energy from ATP hydrolysis.

Question 14

How are primary and secondary active transport related?

Accepted Answer

Secondary active transport uses the concentration gradient established by primary active transport.

Question 15

Which of the following is NOT a true statement regarding exocytosis?

Accepted Answer

It forms intracellular vesicles from inward folding of the plasma membrane.

Question 16

Which of the following best describes the difference between simple and facilitated diffusion?

Accepted Answer

Facilitated diffusion requires a protein transporter.

Question 17

Which direction would you expect water to move across the cell membrane if the outside solution is hypertonic to the inside?

Accepted Answer

Out of the cell.

Question 18

Which option below best describes a transporter that requires ATP to move molecules A and B out of the cell?

Accepted Answer

An active antiporter.

Question 19

Which means of particle transport is responsible for the secretion of hormones and neurotransmitters from cells?

Accepted Answer

Exocytosis.

Question 20

A white blood cell engulfs a bacterium by which process?

Accepted Answer

Phagocytosis.

Membrane Structure and Function: Study Notes

Study Guide - Practice Questions