3. Enzymes and Digestion Quiz

What determines the shape of the active site in enzymes?

• Secondary structure

• Quaternary structure

• Tertiary structure

• Primary structure

What happens to an enzyme when it denatures?

• It becomes more effective

• It loses its shape

• It increases its activity

• It binds more substrates

At what pH do most enzymes work best?

• 5

• 7.4

• 2

• 9

What effect does increasing temperature have on enzyme activity up to a certain point?

• Denatures the enzyme

• Increases the rate of reaction

• Decreases the rate of reaction

• Has no effect

What is the optimal temperature for enzyme activity generally?

• 37°C

• 100°C

• 25°C

• 0°C

What occurs when all active sites of an enzyme are occupied?

• The reaction rate increases

• The reaction rate decreases

• The enzyme denatures

• The maximum rate is reached

What is the lock and key model used to describe?

• Protein synthesis

• Cell division

• The structure of DNA

• Enzyme-substrate interactions

What happens to the active site of an enzyme when it denatures?

• It becomes more rigid

• It changes shape

• It remains unchanged

• It increases in size

Which of the following factors does NOT affect enzyme action?

• Color of the enzyme

• Temperature

• Substrate concentration

• pH

What is the effect of increasing enzyme concentration on the rate of reaction?

• It increases the rate

• It stops the reaction

• It has no effect

• It decreases the rate