Enzymes - 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 determines the specificity of an enzyme?

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