Metabolism and Enzymes Quiz

What is the 'lock and key' hypothesis?

• Enzymes are locked in place

• Substrates fit into enzymes like keys fit into locks

• Enzymes can change shape

• Substrates are destroyed by enzymes

What is the effect of substrate concentration on enzyme action?

• It always increases the reaction rate

• It increases the reaction rate until a maximum level is reached

• It has no effect

• It decreases enzyme activity

How does temperature affect enzyme activity?

• Higher temperatures always increase activity

• Lower temperatures always decrease activity

• Enzymes have an optimum temperature for activity

• Temperature has no effect on enzyme activity

What is the effect of increasing enzyme concentration?

• It decreases the reaction rate

• It always decreases enzyme activity

• It increases the reaction rate until substrate becomes limiting

• It has no effect on the reaction rate

What is activation energy?

• Energy required for muscle contraction

• Energy stored in ATP

• Energy released during a reaction

• Energy needed to break bonds in substrates

What happens when pH levels are extreme for an enzyme?

• Enzyme activity increases

• Enzyme activity remains the same

• Enzyme concentration increases

• Enzyme denatures and loses function

What happens to enzymes at high temperatures?

• They become more active

• They denature and lose function

• They increase in concentration

• They produce more substrates

What is the optimum pH for pepsin?

• 8

• 2.4

• 6

• 7

What is the role of enzymes in biochemical reactions?

• To slow down reactions

• To increase the rate of reactions

• To change the products of reactions

• To provide energy for reactions

What is catabolism?

• The storage of energy in cells

• The conversion of light energy to chemical energy

• The process of breaking down complex substances

• The process of synthesizing complex molecules