BIO5 Ch4 Enzymes

  1. enzyme
    subclass of proteins, biological catalysts that increase the rate of chemical reactions
  2. catalyst
    • a chemical that:
    • 1. increases the rate of a reaction
    • 2. is not itself changed at the end of the reaction
    • 3. does not change the nature of a reaction or its final result
  3. activation energy
    the amount of energy required for a reaction to proceed
  4. conformation
    an enzyme's three-dimensional shape
  5. active site
    the groove (containing specific amino acids) on an enzyme's conformation that are active in catalyzing a reaction
  6. substrates
    the reactants in a chemical reaction
  7. lock-and-key model
    a unit of enzyme + substrates in which the substrates have specific shapes which allow them to fit into the active sites
  8. induced-fit model
    a unit of enzyme + substrates in which the enzyme undergoes a slight structural change to better fit the substrate
  9. enzyme-substrate complex
    the unit of enzyme plus substrates
  10. products
    the end results of a chemical reaction
  11. hydrolases
    promote hydrolysis reactions
  12. phosphatases
    promote removal of phosphate groups
  13. synthases and synthetases
    catalyze dehydration synthesis reactions
  14. dehydrogenases
    remove hydrogen atoms from their substrates
  15. kinases
    add a phosphate group to particular molecules
  16. isomerase
    rearrange atoms within their substrate molecules to form stereoisomers
  17. isoenzymes
    different models of the same enzyme
  18. pH optimum
    the pH environment in which an enzyme exhibits peak activity
  19. cofactors
    metal ions such as calcium, magnesium, manganese, copper, zinc, selenium
  20. coenzymes
    organic molecules derived from water-soluble vitamins such as niacin and riboflavin
  21. zymogens
    inactive digestive enzymes
  22. turnover
    the breakdown and resynthesis of enzymes
  23. saturated (enzyme activity)
    when the relationship between substrate concentration and reaction rate reaches a plateau of maximum velocity
  24. law of mass action
    the principle that reversible reactions will be driven from the side of the equation where the concentration is higher to the side where the concentration is lower
Card Set
BIO5 Ch4 Enzymes
Ch 4: Energy and Enzymes vocabulary