Enzymes

• What is a cofactor in enzyme-controlled reactions?

  A non-protein molecule required for reactions
• Why are some enzymes dependent on cofactors?

  They ensure proper enzyme function
• What are the two main types of cofactors?

  1. Inorganic cofactors (e.g., ions like Cl⁻)
  2. Organic cofactors (coenzymes) (e.g., coenzyme A or NAD)
• What is a prosthetic group?

  A permanently bound cofactor for enzymes
• How do inorganic cofactors assist enzymes?

  They help bind the enzyme and substrate
• Do inorganic cofactors participate in the reaction?

  No, they do not change during the reaction
• Give an example of an inorganic cofactor.

  Chloride ions (Cl⁻) for amylase
• What are coenzymes?

  Organic molecules that participate in reactions
• How are coenzymes recycled?

  They are regenerated at the end of reactions
• What role does coenzyme A (CoA) play in respiration?

  It carries acetate to the next stage
• What happens to coenzyme A after delivering acetate?

  It is regenerated to collect more acetate
• How does NAD function as a coenzyme?

  NAD picks up hydrogen atoms to become reduced
• What happens to NAD after releasing hydrogen?

  NAD is oxidized back to its original form
• From what are many coenzymes synthesized?

  Many coenzymes are synthesized from vitamins
• Do cofactors remain unchanged at the end of reactions?

  Yes, they remain unchanged or are recycled
• What are prosthetic cofactors?

  Non-protein molecules permanently bound to enzymes
• How do prosthetic cofactors differ from other types of cofactors?

  They are permanently attached to the enzyme
• Give an example of a prosthetic cofactor.

  Zinc ions (Zn²⁺) in carbonic anhydrase
• What is the role of zinc ions (Zn²⁺) in carbonic anhydrase?

  They help catalyze the formation of carbonic acid
• Where is carbonic anhydrase found, and what is its function?

  Found in red blood cells, catalyzes carbonic acid formation
• What is an enzyme inhibitor?

  A substance that slows down enzyme reactions
• What are the two main types of enzyme inhibition?

  1. Competitive inhibition
  2. Non-competitive inhibition
• Can enzyme inhibition be reversible or irreversible?

  Yes, it can be reversible or non-reversible
• How do competitive inhibitors interact with enzymes?

  They bind to the enzyme’s active site
• Why do competitive inhibitors slow down enzyme activity?

  They prevent the normal substrate from binding
• Do competitive inhibitors have the same shape as the enzyme’s substrate?

  No, they have a similar shape
• How does substrate concentration affect competitive inhibition?

  High concentrations can reduce inhibitor effects
• What happens at high inhibitor concentrations in competitive inhibition?

  Collisions with the active site are more likely
• Where do non-competitive inhibitors bind on an enzyme?

  To a site other than the active site
• How do non-competitive inhibitors affect enzyme activity?

  They change the shape of the enzyme’s active site
• Does increasing substrate concentration affect non-competitive inhibition?

  No, it does not affect the reaction rate
• What determines the rate of enzyme-controlled reactions in non-competitive inhibition?

  The number of non-competitive inhibitor molecules
• What is a biological catalyst?

  A globular protein, that contains carbon, that increases the rate of reaction by decreasing the activation energy. It's not used up in the reaction.
• What are enzymes?

  Biological catalysts that speed up reactions
• What is the role of enzymes in chemical reactions?

  They speed up reactions without being used up
• What is the structure of enzymes?

  Globular proteins with specific tertiary structure
• What are the two types of metabolic reactions catalyzed by enzymes?

  • Catabolic: Breaking large molecules into smaller ones
  • Anabolic: Building smaller molecules into larger ones
• Give an example of a catabolic enzyme.

  Protease
• What does lipase do?

  Hydrolyses ester bonds in lipids
• What is the function of amylase?

  Hydrolyses starch into alpha-glucose