AP Bio Enzymes Level 2

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

• the starch solution has less free energy than the sugar solution.

• the hydrolysis of starch to sugar is endergonic.

• the activation energy barrier for this reaction cannot easily be surmounted at room temperature.

• starch cannot be hydrolyzed in the presence of so much water.

Tags

NGSS.HS-PS1-4

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

• denaturation of the enzyme

• allosteric inhibition

• competitive inhibition

• saturation of the enzyme activity

Some of the drugs used to treat HIV patients are competitive inhibitors of the HIV reverse transcriptase enzyme. Unfortunately, the high mutation rate of HIV means that the virus rapidly acquires mutations with amino acid changes that make them resistant to these competitive inhibitors. Where in the reverse transcriptase enzyme would such amino acid changes most likely occur in drug-resistant viruses?

• in or near the active site

• at an allosteric site

• at a cofactor binding site

• in regions of the protein that determine packaging into the virus capsid

Tags

NGSS.HS-LS3-2

NGSS.HS-LS4-4

When you have a severe fever, what grave consequence may occur if the fever is not controlled?

• destruction of your enzymes' primary structure

• removal of amine groups from your proteins

• change in the tertiary structure of your enzymes

• removal of the amino acids in the active sites of your enzymes

How might an amino acid change at a site distant from the active site of the enzyme alter the enzyme's substrate specificity?

• by changing the enzyme's stability

• by changing the enzyme's location in the cell

• by changing the shape of the protein

• by changing the enzyme's pH optimum

For the enzyme-catalyzed reaction shown in Figure 6.2, which of these treatments will cause the greatest increase in the rate of the reaction, if the initial reactant concentration is 1.0 micromolar?

• doubling the activation energy needed

• cooling the reaction by 10°C

• doubling the concentration of the reactants to 2.0 micromolar

• doubling the enzyme concentration

In Figure 6.2, why does the reaction rate plateau at higher reactant concentrations?

• Feedback inhibition by product occurs at high reactant concentrations.

• Most enzyme molecules are occupied by substrate at high reactant concentrations.

• The reaction nears equilibrium at high reactant concentrations.

• The activation energy for the reaction increases with reactant concentration.

Tags

NGSS.HS-PS1-5

Which of the following in Figure 6.4 would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

• a

• b

• c

• d

Tags

NGSS.HS-PS1-4

Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction, C + D → A + B, in Figure 6.4?

• a

• b

• c

• d

Tags

NGSS.HS-PS1-4

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid.

Based on this information, which of the following is correct?

• Succinate dehydrogenase is the enzyme, and fumarate is the substrate.

• Succinate dehydrogenase is the enzyme, and malonic acid is the substrate.

• Succinate is the substrate, and fumarate is the product.

• Fumarate is the product, and malonic acid is a noncompetitive inhibitor.