Chapter 6 Key Terms

  1. Metabolism (2)
    • The totality of an organism's chemical reactions
    • Transforms matter and energy, subject to the laws of thermodynamics
  2. Metabolic Pathway
    Begins with a specific molecule and ends with a product, and each step is catalyzed by a specific enzyme
  3. Catabolic Pathways
    Release energy by breaking down complex molecules into simpler compound
  4. Cellular Respiration
    A catabolic pathway in which glucose is broken down in the presence of oxygen
  5. Anabolic Pathways
    Consume energy to build complex molecules from simpler ones
  6. Bioenergetics
    The study of how energy flows through organisms
  7. Energy (2)
    • Capacity to cause change 
    • Can be converted from one form to another
  8. Kinetic Energy
    Energy associated with motion
  9. Potential Energy
    Energy that matter possesses because of its location or structure
  10. Chemical Energy
    Potential energy available for release in a chemical reaction
  11. Thermodynamics
    The study of energy transformations
  12. Isolated System
    Energy and matter cannot be transferred between the system and its surroundings
  13. Open System (2)
    • Energy and matter can be transferred between the system and its surroundings
    • Ex: Organisms
  14. First Law of Thermodynamics (2)
    • The energy of the universe is constant 
    • It can be transferred and transformed, but it can't be destroyed
  15. Second Law of Thermodynamics
    Every energy transfer or transformation increases the entropy (disorder) of the universe
  16. Free Energy
    Energy that can do work when temperature and pressure are uniform, as in a living cell
  17. - ΔG (2)
    • Spontaneous process
    • Can be harnessed to perform work
  18. Equilibrium (3)
    • State of maximum stability
    • A process is spontaneous and can perform work only when it is moving toward equilibrium
    • Metabolism is never at equilibrium
  19. Exergonic Reaction
    Proceeds with a net release of free energy and is spontaneous (-ΔG)
  20. Endergonic Reaction
    Absorbs free energy from its surroundings and is nonspontaneous (+ΔG)
  21. Energy Coupling (3)
    • The use of an exergonic process to drive an endergonic one
    • Used by cells to manage energy resources
    • Mediated by ATP
  22. Catalyst
    Chemical agent that speeds up a reaction without being consumed by the reaction
  23. Activation Energy
    The initial energy needed to start a chemical reaction
  24. Substrate
    The reactant that an enzyme acts on
  25. Enzyme-substrate complex
    Formed after the enzyme binds to its substrate
  26. Active site
    • The region of the enzyme where the substrate binds
    • Can lower the activation energy barrier
  27. Cofactors
    • Nonprotein enzyme helpers
    • May be organic or inorganic
  28. Coenzyme (2)
    • An organic cofactor that is required by an enzyme
    • i.e vitamins
  29. Competitive Inhibitor
    Something that binds to the active site of an enzyme preventing the substrate from binding
  30. Noncompetitive inhibitor (3)
    • Bind to a part of the enzyme that isn't the active site causing the enzyme to lose shape
    • Makes the active site less effective/accessible
    • Ex: toxins, poisons, pesticides, antibiotics
  31. Allosteric Regulation
    • Can either inhibit or stimulate an enzyme's activity
    • Occurs when a regulatory molecule binds to a protein at one site and affects the proteins function at another
  32. Allosteric Regulators
    DO NOT bind to the active site of an enzyme
  33. Allosteric Activators
    Bind to the enzyme and stabilize the active form
  34. Allosteric Inhibitors
    Bind to the enzyme and stabilize the inactive  form of the enzyme
  35. Feedback Inhibition (2)
    • The end product of a metabolic pathway inhibits an enzyme in the pathway, shutting down the pathway
    • Prevents a cell from wasting resources by synthesizing more product than is needed
Card Set
Chapter 6 Key Terms
key terms from chapter 6