Enzyme Inhibition Quiz

Competitive inhibitors bind to the enzyme's active site.

• True

• False

Non-competitive inhibitors have a structure similar to the substrate.

• True

• False

Answer explanation

Non-competitive inhibitors bind to an allosteric site (not the active site) and do not resemble the substrate. Their binding changes the enzyme's conformation, preventing catalysis but not substrate binding.

Malonate is an example of a competitive inhibitor for succinate dehydrogenase.

• True

• False

Increasing substrate concentration can overcome the effects of non-competitive inhibition.

• True

• False

Answer explanation

Non-competitive inhibitors act by altering the enzyme's shape, not by competing with the substrate. Adding more substrate cannot reverse this type of inhibition.

In competitive inhibition, the Vmax of the enzyme remains unchanged.

• True

• False

In non-competitive inhibition, the inhibitor decreases the enzyme's Km value.

• True

• False

Answer explanation

Non-competitive inhibition does not change the Km (substrate affinity) because the substrate can still bind. However, it decreases the enzyme's Vmax (maximum reaction rate).

Uncompetitive inhibitors bind only to the enzyme-substrate complex, not the free enzyme.

• True

• False

Allosteric inhibitors change the shape of the enzyme, altering its active site.

• True

• False

Mixed inhibitors bind exclusively to the active site of the enzyme.

• True

• False

Answer explanation

Mixed inhibitors bind to both the enzyme and the enzyme-substrate complex, but not exclusively to the active site. They can bind to allosteric sites as well, affecting both Km and Vmax.

Competitive inhibition increases the Km of the enzyme but does not affect Vmax.

• True

• False