C1.1 Enzymes and Metabolism

Question 1

Define enzymes and their use

Answer 1

Enzymes are biological catalysts that increase the rate of a reaction but remain unchanged.

Question 2

What is the role of enzymes in metabolism?

Answer 2

• Metabolism: the complex network of interdependent and interacting chemical reactions occurring in living organisms.
• Each enzyme catalyses one or a group of specific reactions.
• Due to this enzyme specificity, living organisms require many different enzymes, and control over metabolism can be exerted through these enzymes.

Question 3

Describe anabolic reactions

Answer 3

• Anabolic reactions build up smaller molecules into larger ones
• Examples:
  – protein synthesis
  – glycogen formation
  – photosynthesis

Question 4

Describe catabolic reactions

Answer 4

• Catabolic reactions break down larger molecules into smaller ones.
• Examples:
  – hydrolysis of macromolecules into monomers in digestion
  – oxidation of substrates in respiration

Question 5

Active site of enzymes

Answer 5

The active site of enzymes only has a few AAs but the interactions between the AAs within the overall 3D structure of the enzyme ensure that it has the necessary properties for catalysis. Properties such as binding to the substrate molecule, holding onto it while the chemical reaction takes place, and lowering the energy of the transition state.

Question 6

Describe induced-fit binding