Final Final Final Flash cards`

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Final Final Final Flash cards`
2014-12-09 21:22:51
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  1. dehydrogenase
    enzyme that couples two reactions; the highly unfavorable with the highly favorable

    remove electrons and hydrogen ions with release of free energy
  2. How does glyceraldehyde 3-phosphate dehydrogenase catalyze the reaciton?
    it is an oxidation and an acyl-phosphate formation (dehydration)

    The thioester intermediate that forms reduces the free energy required to get the acyl-phosphate formation to occur

    cysteine acts as the nucleophile
  3. What does alcohol dehydrogenase have that allows alcohol fermentation go to completion?
    it has a zinc molecule, which polarizes the bonds
  4. How much ATP is expended when fructose enters the pathway? What is the mechanism?
    tw ATP

    fructose--> fructose 1-phosphate (by fructokinase)--> glyceraldehyde and dihydroxyacetone phosphate (fructose 1-phosphate aldolase)

    glyceraldehyde converted by triose kinase to G3P
  5. What is the equation for the linker reaction?
    pyruvate + NAD+ + CoA---> acetyl-CoA + CO2 + NADH
  6. How many electrons are captured in CAC?
  7. Where does the CAC take place? 

    What is the problem with pyruvate in terms of location?
    in the matrix

    pyruvate can' tget through on its own and so pyruvate translocase is needed. It is a symporter that transports pyruvate against its concentration gradient into the matrix using protons as energy
  8. What makes TPP good?
    highly acidic; can use a proton and pyruvate
  9. What does binding of TPP to pyruvate to form hydroxyethyl-TPP do?
    • 1) captures energy associated with decarboxylation
    • 2) allows decarboxylation to happen
  10. How does the lipoamide arm work?
    The SS bond breaks; one side binds the acetyl goroup; the other accepts electrons
  11. What forms after the exchange to CoA?
    dihydrolipoamide which must be oxidized
  12. What does the complex contain?
    channels through which pyruvate enters and is trapped
  13. What does citrate synthase demonstrate?
    it demonstrates sequential ordered kinetics
  14. How does succinyl CoA synthetase allow the reaction to occur?
    a Pi group comes in and energy from attaching succinate to CoA will supply energy
  15. What up with the citrate synthase enzyme?
    it binds the enz in one conformation
  16. What do all Fe-S clusters do?
    they all accept and pass on e-
  17. What is the reaction for Complex I?
    NADH + Q + 5 H+matrix --> NAD+ + QH2 + 4 H+cytoplasm
  18. What is the reaction for Complex III?
    QH2 + 2 Cyt c (oxidized) + 2 H+ (matrix) --> Q + 2 Cyt c (red) + 4 H+(cytoplasm)
  19. How many electrons reduce O2 to water?
    four electrons

    cyt c docks on one at a time
  20. How many hydrogens are used for water?
    two hydrogens to break the bond between the two; and two to reduce
  21. What is the reaction for Complex IV?
    4 cyt c (reduced) + 8 H+ (matrix) + O2--> 4 cyt c (ox) + 2 H2O + 4 H+ (cytoplasm)
  22. Which complexes pump protons?
    • III
    • IV
  23. which amino acids does alpha-ketoglutarate make?
    • glutamate
    • glutamine
    • proline
    • arginine
  24. which amino acids does oxaloacetate make?
    • aspartate
    • asparagine
    • methionine
    • threonine
    • isoleucine
    • lysine
  25. What are the three ways of turning proteins on or off?
    • allosterically (most rapid)
    • reversible cov. modification (longer dueto kinase being recruited)
    • control amount of enzyme at level of transcription
  26. Why must the PDC be regulated?
    becuase pyruvate can be made to glucose adn vice versa but once converted to acetyl CoA, there's no turning back
  27. What is brown fat?
    adipose cells with a lot of mitochondrion in them; found in animals that like to hibernate

    these mitochondria produce H+ gradient. Proteins in the membranes of these mitochondria are uncoupling proteins (UCP_ which uncouple the link betwee e transport and use it to make ATP; allows building and flow of H+, making heat
  28. What are all the things proton gradients are used for?
    • ATP ~P
    • NADPH synthesis
    • Heat production
    • Electron potential
    • Active transport
    • Flagellar rotation