Card Set Information

2013-01-30 17:20:26

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  1. Metabolism?
    collection of controlled biochemical reactions that takes place within the cells of an organism.
  2. anabolism?
    • all of the synthesis reactions in an organism taken together.
    • building reaction
  3. catabolism?
    • All of the decomposition reactions in an organism taken together.
    • break down reactions
    • release energy
  4. How do cells use nutrients and energy to build structure , grow, and reproduce through Metabolic processes?
    • 1- every cell requires nutrients
    • 2- metabolism requires energy from light or from catabolism of nutrients
    • 3- energy is stored in the chemical bonds of adenosine triphosphate (ATP)
    • 4- using enzymes, cells catabolize nutrient molecules to form elementary building blocks called precursor molecules.
    • 5- using precursor molecules, energy from ATP, and enzymes, cells construct larger building blocks in anabolic reactions.
    • 6- cells use enzymes and additional energy from ATP to anabolically link building blaock from macromolecules in polymerization ractions
    • 7- cells assemble macromolecules into cellular structure, ribosomes, membranes, cell walls, etc
    • 8- cells typically reproduce once they have doubled in size
  5. Contrast Oxidation and Reduction reactions:
    • reduction- gain an electron
    • oxidation- lose an electron
  6. What is the function of NAD+, NADP+, and FAD+?
    • NAD+: vitamin derived electron carrier molecule
    • NADP+: Vitamin derived electron carrier molecule
    • FAD+:Vitamin derived electron carrier molecule
    • reducing power
  7. What are the three types of ATP phosphorylation?
    • substrate- level phosphorylation: transfer of phosphate to ADP from another phosphorylated substrate. (Glycolysis krebs cycle)
    • Oxidative phophorylation: energy from redox reactions of respiration used to attach phosphate to ADP (ETC- electron transport chain)
    • Photophosphorylation: light energy used to phosphorylate ADP
  8. What are the 6 basic categories of enzymes, and what type of reaction does each catalyze?
    • hydrolases: catabolize molecules with the addition of water
    • Isomerases: rearrange atoms within a molecule, nothing added or taken away
    • Ligases or polymerases: join 2 molecules together- anabolic, need ATP.
    • Lyases: split molecules w/o using water
    • Oxidoreductases: remove or add electrons
    • Transferases: Transfer functional groups
  9. Describe the components of a holoenzyme?
    combination of an apoenzyme and its cofactors. 
  10. apoenzyme?
    Protein portion of protein enzymes that is inactive unless bound to one or more cofactors.
  11. cofactor?
    inorganic ions or organic molecules that are essential for enzyme action.
  12. coenzyme?
    organic cofactor
  13. Describe how Temperature, pH, and substrate concentration effect enzymes activity
    • temperature- if too high or too low and enzyme is often no longer able to achieve a fit with its substrate
    • pH- extremes denature enzymes. eahc enzyme has optimal pH
    • substrate- increases enzymatic activity increases as more an more enzyme active sites bind more an more substrate molecules.
  14. Describe how competitive and noncompetitive inhibitors affect enzyme activity.
    • Competitive- shaped such that they fit into an enzyme's active site and and thus prevent the normal substrate from binding.
    • Noncompetitive- do not bind to the active site but instead prevent enzymatic activity by binding to an allosteric site located elsewhere on the enzyme
  15. How negative feedback (end-product inhibition) prevents the cell from wasting energy making a lot of unneeded product?
    • end-product of a series of reactions inhibits an enzyme in an earlier part of the pathway.
    • In E.coli the presence of the amino acid isoleucine allosterically inhibits the first enzyme in the anabolic pathway that produces isoleucine.