Cofactor & Inhibitor

Blocking active site of an enzyme

• competitive inhibition

• non-competitive inhibition

Which of the following is directly responsible for the shape of an enzyme/protein?

• The amino acid sequence of the protein and the properties of the amino acids that make up the protein.

• The temperature of the surrounding environment.

• The pH of the surrounding environment.

• The amount of substrate present.

Vitamin C is

• Cofactor

• Coenzyme

• Metal ion activator

Iron is

• Coenzymes

• Cofactors

• Metal ion activator

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

According to the induced fit hypothesis of enzyme catalysis, which of the following is CORRECT?

• The binding of the substrate slightly changes the shape of the enzyme’s active site

• Some enzymes change their structure when activators bind to the enzyme

• The binding of the substrate depends on the shape of the active site

• A competitive inhibitor can out-compete the substrate for the active site

A series of enzymes catalyze the reaction A --> B --> C --> D. Product D binds to the enzyme that converts A to B at a position other than its active site. This binding decreases the activity of the enzyme. What is substance A?

• Substrate

• Product

• Coenzyme

• Inhibitor

A series of enzymes catalyze the reaction A --> B --> C --> D. Product D binds to the enzyme that converts A to B at a position other than its active site. This binding decreases the activity of the enzyme. What is the function of substance D?

• Substrate

• Product

• Competitive inhibitor

• Non-competitive inhibitor

Cofactors for enzyme are accurately described as

• The protein substance

• The non-protein substance

• The inorganic substance

• The organic substance