Question 1

Which of the following statements correctly describes the effect of an enzyme on a chemical reaction's energy diagram?

Accepted Answer

The enzyme lowers the activation energy but does not change $$\Delta G.$$

Question 2

A reaction has a $$\Delta G of$$ $$-30 kJ/$$mol. After adding an enzyme, what is the new $$\Delta G$$ for the reaction?

Accepted Answer

$$-30 kJ/$$mol

Question 3

On an energy diagram, how is the activation energy ($$E_a) $$measured?

Accepted Answer

From the energy level of the reactants to the top of the energy peak.

Question 4

Which molecule would diffuse most slowly through a pure phospholipid bilayer?

Accepted Answer

Potassium ion ($$K^+)$$

Question 5

Arrange the following molecules in order from fastest to slowest rate of diffusion through a cell membrane: glucose, $$O_2$$, $$K^+$$, water, steroid hormone.

Accepted Answer

$$O_2$$ \u003e steroid hormone \u003e water \u003e glucose \u003e $$K^+$$

Question 6

Why does glucose diffuse more slowly through the plasma membrane than water?

Accepted Answer

Glucose is both larger and more polar than water.

Question 7

During cellular respiration, how many carbon dioxide ($$CO_2) $$molecules are released from the complete breakdown of one glucose molecule?

Accepted Answer

6

Question 8

If one molecule of G3P (glyceraldehyde-3-phosphate) is fully oxidized in cellular respiration, how many $$CO_2$$ molecules are produced?

Accepted Answer

3

Question 9

In the Calvin cycle, how many turns are required to produce one net G3P molecule?

Accepted Answer

3

Question 10

Where is the first carbon dioxide ($$CO_2) $$released during the breakdown of glucose in cellular respiration?

Accepted Answer

During pyruvate oxidation

Question 11

Which of the following best describes receptor-mediated endocytosis?

Accepted Answer

Specific ligands bind to receptors on the cell surface, triggering vesicle formation that brings the ligands and receptors into the cell.

Question 12

After receptor-mediated endocytosis, where are the receptor proteins located?

Accepted Answer

On the inside of the newly formed vesicle

Question 13

During exocytosis, what happens to the contents of the vesicle?

Accepted Answer

They are released to the outside of the cell.

Question 14

Put the following steps in order for a protein that is secreted from a cell: plasma membrane, Golgi trans face, rough ER, Golgi cis face.

Accepted Answer

Rough ER → Golgi cis face → Golgi trans face → plasma membrane

Question 15

Which type of molecule requires a transport protein every time it crosses the plasma membrane?

Accepted Answer

Ions such as $$H^+$$ and $$K^+$$

Question 16

A scientist adds an enzyme to a reaction and observes that the reaction proceeds much faster. Which of the following best explains this observation?

Accepted Answer

The enzyme lowers the activation energy ($$E_a$$), making it easier for reactants to reach the transition state.

Question 17

If a cell needs to import a large quantity of cholesterol (a large nonpolar molecule), which process is most likely to be used?

Accepted Answer

Receptor-mediated endocytosis

Question 18

Which of the following best explains why steroid hormones cross the plasma membrane faster than water, even though they are larger?

Accepted Answer

Steroid hormones are nonpolar and hydrophobic, allowing them to dissolve in the membrane's interior.

Question 19

A mutation causes a cell to lack functional receptors on its plasma membrane. Which process would be most directly affected?

Accepted Answer

Receptor-mediated endocytosis

Exam Review Study Guide: Enzymes, Membrane Transport, Carbon Counting, and Vesicular Transport

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