MCAT Bio 1.3

  1. Cofactor
    Any species required by an enzyme to function.
  2. Competitive Inhibitor
    • Binds at the active site
    • Overcome by increasing substrate
  3. Non-competitive inhibitor
    • Binds away from the active site and changes the enzyme's shape
    • Decreases efficiency
  4. Irreversible inhibitor
    Binds covalently to the enzyme and permanently disables it
  5. Positive feedback
    When the product of an enzymatic reaction series returns to activate the enzyme again; occurs less often than negative feedback.

  6. Negative feedback
    A shutdown mechanism for a series of enzymatic reactions; when a series produces a sufficient amount of product it sends a signal back to stop it.

    Blood glucose regulation
  7. Zymogen
    Inactive enzyme precursor. Keeps the enzyme inactive until it has finished folding/being transported to the right place
  8. Allosteric Regulation
    Regulation away from the active site. Feedback inhibitors do not resemble substrate of enzyme being inhibited, they bind and cause a conformational change. There are both allosteric inhibitors and activators.
  9. Kinase function
    Transfers PO₄³⁻ to a substrate - phosphorylates others
  10. Phosphatase function
    Removes PO₄³⁻ from a substrate - dephosphorylates others
  11. Metabolism
    The sum of all chemical reactions in the body.
  12. Respiration
    The breakdown of macromolecules into smaller species to harvest energy.
  13. Facultative aerobes/anaerobes
    An organism that can live in either an aerobic or an anaerobic environment (some types of bacteria; yeasts; individual human cells).
  14. Obligate aerobe
    Organism that REQUIRES oxygen to grow (humans)
  15. Obligate anaerobes
    An organism that MUST live in an anaerobic environment.
  16. Substrate Level Phosphorylation
    Formation of ATP from direct transfer of a phosphate group from a phosphorylated intermediate onto ADP.
  17. Oxidative Phosphorylation
    Oxidation energy is used to create a concentration gradient and use the stored energy from the concentration gradient to create ATP...although oxidation is coupled to phosphorylation in glycolysis, this is NOT an example of oxidative phosphorylation.
  18. Fermentation
    Sole route for many bacteria...used by animals ONLY during oxygen debt.
  19. Ethanol Fermentation
    Ethanol is produced and is the final electron acceptor.
  20. Lactic Acid Fermentation
    Lactate is produced and is the final electron acceptor.
  21. Lipid Metabolism
    Occurs in the Mitochondria; and to a limited degree in the peroxisomes.

    Super long fatty acids are broken into smaller lipids in peroxisomes and these pieces are sent back to the mitochondria where they undergo ß-oxidation.
  22. Beta oxidation
    Fatty acid continues to cycle through beta oxidation getting 2 carbons shorter each time until fatty acid is totaly gone.
  23. Protein Metabolism
    Amino acids are broken down into acetyl CoA and fed into the Kreb's cycle.
  24. Order of Metabolism
    Healthy individuals burn carbohydrates first, then fats, then proteins.
Card Set
MCAT Bio 1.3