CIE AS Biology Quiz: Enzymes and Their Action

What are enzymes primarily classified as?

• Proteins

• Carbohydrates

• Nucleic acids

• Lipids

What is the role of enzymes in living organisms?

• To store genetic information

• To act as structural components

• To slow down chemical reactions

• To speed up chemical reactions

What is the active site of an enzyme?

• The part that binds to the substrate

• The part that stabilizes the enzyme

• The part that binds to the product

• The part that denatures the enzyme

What happens to an enzyme when it is denatured?

• It becomes more active

• It changes shape and loses function

• It increases its substrate affinity

• It becomes a coenzyme

Which of the following is an example of an intracellular enzyme?

• Trypsin

• Amylase

• Pepsin

• Catalase

What is the primary function of catalase?

• To store energy

• To synthesize proteins

• To break down hydrogen peroxide

• To digest carbohydrates

What does the lock-and-key hypothesis describe?

• The process of enzyme denaturation

• The specificity of enzyme-substrate interactions

• The flexibility of enzyme shapes

• The energy changes in reactions

What is the induced-fit hypothesis?

• Enzymes are only active at high temperatures

• Enzymes do not interact with substrates

• Enzymes and substrates can change shape upon interaction

• Enzymes are rigid structures

What is activation energy?

• The energy required to break down products

• The energy needed to initiate a reaction

• The energy stored in substrates

• The energy released during a reaction

How can enzyme activity be measured using colorimetry?

• By measuring temperature changes

• By measuring pH levels

• By measuring light absorbance or transmission

• By measuring enzyme concentration