Q: Which equation best represents the hydrolysis of ATP during primary active transport?

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy}$$

Question 1

Which of the following best describes the process of diffusion across a lipid bilayer?

Accepted Answer

The net movement of solutes from high to low concentration, requiring no energy input.

Question 2

A red blood cell is placed in a hypotonic solution. What will happen to the cell, and why?

Accepted Answer

It will swell and possibly burst because water moves into the cell.

Question 3

Which of the following molecules would diffuse most rapidly across a pure phospholipid bilayer?

Accepted Answer

O$$_2$$

Question 4

What property allows integral membrane proteins to span the lipid bilayer?

Accepted Answer

They are amphipathic, containing both hydrophobic and hydrophilic regions.

Question 5

Which of the following statements about the fluid mosaic model is correct?

Accepted Answer

Phospholipids and proteins can move laterally within the layer.

Question 6

A cell is placed in a solution with a higher solute concentration than its cytoplasm. What is the tonicity of the solution, and what will happen to the cell?

Accepted Answer

The solution is hypertonic; the cell will shrink.

Question 7

Which of the following best describes facilitated diffusion?

Accepted Answer

Passive movement of molecules down their concentration gradient via a protein channel or carrier.

Question 8

The sodium-potassium pump (Na$$^+/K$^+$$ ATPase) moves:

Accepted Answer

3 Na$$^+$$ out and 2 K$$^+ in$$, using ATP.

Question 9

Which equation best represents the hydrolysis of ATP during primary active transport?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + 	ext{energy}$$

Question 10

Which of the following is an example of secondary active transport?

Accepted Answer

Movement of glucose into a cell via the Na$$^+/$$glucose symporter, powered by the Na$$^+$$ gradient.

Question 11

Which of the following statements about membrane channels is correct?

Accepted Answer

They are highly selective and may be gated by voltage, ligands, or mechanical forces.

Question 12

A cell with a membrane potential of $$-70 mV $$has a higher concentration of K$$^+$$ inside than outside. What would happen if a K$$^+$$ channel opens?

Accepted Answer

K$$^+$$ will move out of the cell, making the inside more negative.

Question 13

Which of the following best explains why ions such as Na$$^+$$ and Cl$$^-$$ cannot easily cross the lipid bilayer?

Accepted Answer

They are hydrophilic and repelled by the hydrophobic core of the bilayer.

Question 14

Which of the following is true about aquaporins?

Accepted Answer

They allow the rapid movement of water across the membrane.

Question 15

Which of the following best describes the difference between symport and antiport in secondary active transport?

Accepted Answer

Symport moves two molecules in the same direction; antiport moves them in opposite directions.

Question 16

Which of the following scenarios is an example of passive transport?

Accepted Answer

Glucose moving into a cell via GLUT-1 transporter down its concentration gradient.

Question 17

Which of the following would increase the rate of diffusion of a small, nonpolar molecule across a lipid bilayer?

Accepted Answer

Increasing the concentration gradient across the membrane.

Question 18

Which of the following best describes the role of carrier proteins in membrane transport?

Accepted Answer

They undergo conformational changes to move specific molecules across the membrane.

Question 19

A patient is given an intravenous solution that is isotonic to their blood plasma. What effect will this have on their red blood cells?

Accepted Answer

The cells will remain unchanged.

Chapter 6b: Lipids, Membranes, and Membrane Transport

Study Guide - Practice Questions

Study Guide - Flashcards