Enzyme Action & Factors - exam practice

Which statement is true of a competitive enzyme inhibitor?

Which statements about enzyme inhibitors are correct?

1 - competitive inhibitors may be similar shapes to the substrate

2 - competitive inhibitors bind to the active site

3 - non-competitive inhibitors alter the shape of the enzyme

4 - non-competitive inhibitors bind to the substrate

Why do large increases in the temperature or pH alter enzyme activity?

1 - they change the three-dimensional shape of the enzyme

2 - they disrupt hydrogen and ionic bonds in the enzyme

3 - they increase hydrophobic interactions in the enzyme

What is the effect of an enzyme in an enzyme-catalysed reaction?

Which of the bonds will be last to break as the temperature of an enzyme is increased?

The effect of substrate concentration on an enzyme-catalysed reaction was measured in three different conditions:

1 - with no inhibitor

2 - with a competitive inhibitor

3 - with a non-competitive inhibitor

The graph shows the results.

Which statement is correct?

The graph shows the effect of temperature on the rate at which the enzyme in a biological washing powder digests and removes fruit juice stains.

Which statements explain the shape of the graph at temperatures higher than T?

1 - bonds are broken between the R groups of the amino acids in the polypeptide chains of the enzyme

2 - there are more collisions between the enzyme and its substrate

3 - the tertiary structure of the enzyme is altered

4 - the shapes of the active site and the substrate are no longer complementary

What is the definition of the Michaelis-Menten constant, K_m, for an enzyme?

What determines the specificity of an enzyme?

By which method can immobilised enzymes be produced?

Which statements about the effect of all enzyme inhibitors are correct?

1 - change the shape of the active site

2 - denature the enzyme

3 - reduce the rate of the enzyme-catalysed reaction