Enzyme Questions Quiz

Which of the following statements is true for all types of enzyme inhibitors?

• They bind to the allosteric site of the enzyme.

• They cause a permanent change in the enzyme's tertiary structure.

• They reduce the rate of the enzyme-catalysed reaction.

• Their effect is always overcome by increasing substrate concentration.

What occurs when the temperature is increased significantly past an enzyme's optimum?

• The rate of reaction increases linearly.

• The bonds in the enzyme's tertiary structure break, causing denaturation.

• The enzyme's active site becomes more complementary to the substrate.

• The enzyme will continue to function at its maximum possible rate.

In the presence of a competitive inhibitor, what happens if the substrate concentration is increased?

• The rate of reaction decreases because the inhibitor binds more strongly.

• The rate of reaction increases as the substrate outcompetes the inhibitor for the active site.

• The rate of reaction is not affected.

• The enzyme becomes denatured.

A biological detergent contains lipase to break down fat stains. What chemical process does the lipase catalyse?

• Condensation of peptide bonds

• Hydrolysis of glycosidic bonds

• Condensation of ester bonds

• Hydrolysis of ester bonds

In an investigation into the effect of pH on the rate of reaction of catalase from potato cubes, which of the following is the dependent variable?

• The pH of the solution

• The amount of oxygen produced over time

• The temperature of the reaction

• The volume of hydrogen peroxide used

Why do protease enzymes only break down proteins and not other molecules like carbohydrates or lipids?

• Because proteins are the only molecules held together by chemical bonds.

• Because the active site of the protease is complementary to the shape of the protein substrate.

• Because proteases only function in highly acidic conditions.

• Because proteins provide more energy than other molecules.

Pepsin is a protease that digests proteins in the stomach. This reaction is best described as:

• Anabolic

• Condensation

• Catabolic

• Isomeric

What is the key difference between the lock and key model and the induced fit model of enzyme action?

• In the induced fit model, the active site changes shape upon binding the substrate.

• In the lock and key model, the substrate changes shape to fit the active site.

• Only the lock and key model results in an enzyme-substrate complex.

• The induced fit model applies only to extracellular enzymes.

When investigating the enzyme lipase, the pH must be maintained because the hydrolysis of its substrate produces acidic products. What are the products of the hydrolysis of triglycerides?

• Amino acids

• Monosaccharides

• Glycerol and fatty acids

• Nucleotides

How is an extracellular enzyme defined?

• An enzyme that functions within the cytoplasm of a cell.

• An enzyme that functions inside a cell's organelles.

• An enzyme that is secreted from a cell and functions outside of it.

• An enzyme that requires a coenzyme to function.