Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

Diverse proteins embedded in a phospholipid bilayer.

Question 2

A patient receives an organ transplant. To minimize rejection, which cell component must be closely matched between donor and recipient?

Accepted Answer

Cell-surface carbohydrates

Question 3

Which of the following molecules would have the most difficulty crossing a biological membrane by simple diffusion?

Accepted Answer

$$\mathrm{Na^+}$$

Question 4

Osmosis is best defined as:

Accepted Answer

The diffusion of water.

Question 5

A red blood cell placed in a hypotonic solution will:

Accepted Answer

Lyse.

Question 6

If you drink seawater when stranded at sea, what will happen to your cells?

Accepted Answer

You dehydrate yourself.

Question 7

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

Accepted Answer

Transport proteins . . . down

Question 8

Which of the following processes can move a solute against its concentration gradient?

Accepted Answer

Active transport

Question 9

Which of the following is a typical feature of an ATP-driven active transport mechanism?

Accepted Answer

The solute moves against the concentration gradient.

Question 10

Which of the following statements about thermodynamics is false?

Accepted Answer

An automobile engine is a closed system because it does not exchange energy and matter with its surroundings.

Question 11

According to the first law of thermodynamics,

Accepted Answer

Energy cannot be created or destroyed.

Question 12

Which of the following processes is endergonic?

Accepted Answer

The synthesis of glucose from carbon dioxide and water

Question 13

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.

Accepted Answer

Exergonic . . . endergonic

Question 14

The transfer of a phosphate group to a molecule or compound is called:

Accepted Answer

Phosphorylation.

Question 15

Which of the following statements regarding enzyme function is false?

Accepted Answer

Enzymes are used up when they catalyze a chemical reaction, so must be synthesized for each new chemical reaction.

Question 16

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action?

Accepted Answer

Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.

Question 17

How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor?

Accepted Answer

Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.

Question 18

Refer to the image of four cells. Which figure depicts an animal cell placed in a solution hypotonic to the cell?

Accepted Answer

Cell A

Question 19

Refer to the ATP molecule diagram. Which part of the ATP molecule breaks free of the rest when an ATP molecule is used for energy?

Accepted Answer

Part D

Cell Membrane Structure, Transport, and Energy – Guided Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard