BIO150 Enzyme Exercise

The main function of an enzyme is to:

• Act as a reactant

• Speed up chemical reactions

• Be consumed in a reaction

• Act as a substrate

The enzyme-substrate interaction is explained by which theory where the substrate fits perfectly into the enzyme's active site?

• Induced Fit Theory

• Lock and Key Theory

• Activation Energy Theory

• Energy-Substrate Theory

The factor that does NOT affect enzyme activity is:

• pH

• Enzyme concentration

• Activation energy

• Light intensity

When the temperature exceeds the optimum for an enzyme, what happens?

• The enzyme's activity increases

• The enzyme becomes denatured

• The substrate binds more effectively

• The enzyme's active site becomes more flexible

An example of an organic cofactor is:

• NAD+

• Zn2+

• FAD

• Mg2+

Cofactors bind to enzymes in the form of:

• Permanently

• Only temporarily

• Irreversibly

• Only under extreme conditions

The active site of an enzyme is:

• Nonspecific

• Fixed in shape

• Complementary to the substrate

• Unaffected by pH

Competitive inhibition occurs when:

• The inhibitor binds at a site other than the active site

• The inhibitor binds tightly and irreversibly to the enzyme

• The inhibitor competes with the substrate for the active site

• The inhibitor increases the enzyme's activity

The effect of a non-competitive inhibitor on the enzyme is:

• It competes with the substrate for the same active site

• It alters the enzyme's shape without competing for the active site

• It increases the enzyme's efficiency

• It is always irreversible

Allosteric regulation affects enzyme activity by:

• Increasing the rate of enzyme synthesis

• Binding substrates at the active site

• Modifying the enzyme's shape and activity

• Preventing enzyme denaturation