Metabolism :p

• What is metabolism?

  A series of chemical reactions that build and break down molecules for cellular processes
• What role do enzymes play in metabolism?

  Enzymes are involved in each step of metabolism
• What is a catabolic pathway?

  A pathway where molecules are broken down
• What is an example of a catabolic pathway?

  Cellular respiration: glucose → energy + CO₂
• What is an anabolic pathway?

  A pathway where molecules are built up
• What is an example of an anabolic pathway?

  Photosynthesis: CO₂ + energy → glucose
• What is Gibbs Free Energy?


  The capacity to do work; measures a system’s ability to do work
• What does a negative ΔG indicate?

  A spontaneous reaction
• What does a positive ΔG indicate?

  It requires energy input to proceed
• What does high Gibbs Free Energy indicate about a system?

  It is unstable and will tend to go to low G until equilibrium is reached
• What is an exergonic reaction?

  A reaction that releases energy
• What is an endergonic reaction?

  A reaction that requires energy input
• What is energy coupling?

  The use of exergonic reactions to drive endergonic ones
• What is activation energy (EA)?

  The investment of energy required to carry out a reaction
• How do enzymes lower activation energy?

  By acting as a template for orientation, stressing the substrate, providing a favorable microenvironment, and participating directly in the reaction
• What are enzymes?

  Proteins that act as catalysts to speed up reactions
• What is the mechanism by which enzymes work?

  They lower the energy barrier (activation energy)
• What is substrate specificity?

  Enzymes only work with specific substrates
• What is the analogy used to describe enzyme-substrate specificity?

  Like a lock and key
• What is formed when an enzyme and substrate join?

  An enzyme-substrate complex
• What factors affect enzyme activity?

  • pH
  • Temperature
  • Cofactors
  • Coenzymes