Coenzymes

• What should you be able to describe by the end of this video?

  The role of cofactors, coenzymes, and prosthetic groups
• What is the active site of an enzyme?

  It is where the substrate binds
• What forms when a substrate binds to an enzyme?

  The enzyme-substrate complex
• What happens after the enzyme-substrate complex is formed?

  The enzyme catalyzes the reaction
• What is the product of the reaction catalyzed by amylase?

  Maltose
• What additional ion is required for amylase to catalyze its reaction?

  The chloride ion
• Is chloride a substrate for amylase?

  No, it is a cofactor
• What type of molecules can cofactors be?

  Simple ions or complex organic molecules
• What does the term "organic" refer to in biochemistry?

  Based on the element carbon
• What is an example of a large organic cofactor?

  NAD
• What is the role of NAD in respiration?

  To transfer hydrogen atoms between molecules
• From what vitamin is NAD derived?

  Niacin (Vitamin B3)
• How do cofactors differ in their binding to enzymes?

  Some bind permanently, others temporarily
• What is a prosthetic group?

  A permanent part of the enzyme structure
• What is an example of an enzyme that contains a prosthetic group?

  Carbonic anhydrase
• What ion is permanently bound to carbonic anhydrase?

  The zinc ion
• What are the roles of cofactors, coenzymes, and prosthetic groups in enzymes?

  • Cofactors assist enzymes in catalyzing reactions
  • Coenzymes are large organic cofactors, often derived from vitamins
  • Prosthetic groups are permanently attached to enzymes
• Compare the roles of cofactors and coenzymes.

  • Cofactors: Can be small ions or large molecules
  • Coenzymes: Always large organic molecules, often from vitamins
• What are the differences between temporary and permanent cofactors?

  • Temporary cofactors: Bind and release during reactions
  • Permanent cofactors: Integral parts of enzyme structure