IB Bio HL C1.1.16 End-Product Inhibition

If the final product of a metabolic chain inhibits an upstream enzyme, what is this regulatory mechanism called?

• Substrate activation

• Feedback enhancement

• End-product inhibition

• Competitive activation

What term describes an inhibitor that binds to a site other than the active site of an enzyme, changing its shape?

• Competitive inhibitor

• Allosteric inhibitor

• Substrate analog

• Irreversible inhibitor

How does the final product typically inhibit an upstream enzyme in end-product inhibition?

• By binding to the active site of the enzyme.

• By changing the shape of the enzyme's active site.

• By increasing the activation energy of the reaction.

• By competing with the substrate for the active site.

What is the primary function of end-product inhibition in a metabolic pathway?

• To increase the rate of product formation.

• To regulate the concentration of the final product.

• To convert essential amino acids into non-essential ones.

• To denature enzymes in the pathway.

What would be the immediate effect if the concentration of isoleucine in bacteria became very high?

• The production of threonine would increase.

• The activity of Enzyme 1 would increase.

• The conversion of threonine to intermediate substrate A would slow down.

• The bacteria would start producing a different amino acid.

End-product inhibition is a mechanism that helps maintain what in a metabolic pathway?

• Constant enzyme production.

• Constant substrate availability.

• Relatively constant levels of the final product.

• Rapid consumption of initial reactants.

In the metabolic pathway discussed, what type of molecules are threonine and isoleucine?

• Sugars

• Lipids

• Amino acids

• Nucleic acids

For humans, isoleucine is an essential amino acid. What does this mean?

• Humans can synthesize isoleucine from other amino acids.

• Humans must obtain isoleucine from their diet.

• Isoleucine is not required for human survival.

• Isoleucine is only produced in bacteria.

In bacteria, from which amino acid is isoleucine synthesized?

• Leucine

• Valine

• Threonine

• Alanine

Which enzyme in the threonine to isoleucine metabolic pathway is inhibited by isoleucine?

• Enzyme 1

• Enzyme 2

• Enzyme 3

• All enzymes in the pathway