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Metabolism

  1. Where does Glycolysis take place? Does it require O2?
    In the cytosol. O2 need not be available because glycolysis is the first step of both aerobic and anaerobic respiration.
  2. How is ATP formed in glycolysis, the kreb's cycle, and the electron transport chain? 
    Substrate-level phosphorylation in glycolysis and TCA but oxidative-phosphorylation in ETC.
  3. What happens if one enzyme in the glycolytic pathway is inhibited?
    Buildup of reactants and reduction of products
  4. Fermentation - what are the net products and what kinds of cells employ it? 
    Anaerobic respiration taken up my muscle and bacterial cells. 

    • Net products carry over from glycolysis:
    • 1. 2 ATP
    • 2. Ethanol of lactic acid from conversion of puryvate 
    • 3. NAD+ recovered from glycolysis to reenter cycle 
  5. Net ATP produced from aerobic respiration, including glycolysis 
    36 ATP
  6. Where does TCA take place? 
    In the mitochondrial matrix
  7. What are the products from one turn of the TCA?
    1 ATP ; 3NADH ; 1FADH2 ; oxaloacetate 
  8. Inner mitochondrial matrix vs. Outer mitochondrial matrix
    Outer = permeable to small molecules 

    Inner = less permeable than the outer membrane  
  9. What other macromolecules can enter the TCA?
    Amino acids & triglycerides 
  10. Energy yield of NADH and FADH2 in ETC
    After oxidation: 

    NADH = 2-3 ATPs

    FADH2 = 2 ATPs 
  11. Where is the ETC?
    In the inner mitochondrial membrane - carries out the oxidation of NADH and FADH2 
  12. What is the terminal electron acceptor in the ETC and what is the net product?
    Oxygen - this is why O2 is needed for aerobic respiration. By accepting the electrons, oxygen is reduced to water.
  13. What establishes the proton gradient in the intermembrane space?
    The oxidation of NADH, which allows protons to be pumped into the intermembrane space 
  14. What is the name of the membrane-bound protein responsible for ATP production?
    ATP synthase
  15. Types of transport not requiring energy 
     
    **No energy required because molecules are being moved along their []gradient

    • 1. Facilitated diffusion (glucose) ; assiatance of transport proteins needed
    • 2.  Passive diffusion 
  16. Membrane transport requiring energy 
    **Need ATP because molecules are moved against their []gradient

    Active transport (secondary and primary) 
  17. What molecular factors affect membrane permeability?
    • Molecule size and polarity! 
    • Water is more permeable than Na+ even though it's bigger because it is uncharged.
  18. Do enzymes change the free energy of a reaction? 
    Nope! They also only affect the kinetics of the reaction...not the thermodynamics 
  19. In aerobic metabolism, what happens to the C in glucose, the O in glucose, and the inspired O? 
    C in glucose --> CO2 

    O in glucose --> CO2

    O breathed in --> H2)  
  20. What are glycolysis and TCA inhibited by? 
    ATP! and Krebs by NADH
  21. Net reaction of aerobic respiration and source of products
    C6H12O6 + O2 --> CO2 + H2O (unbalanced).

    Each half of a glucose molecule forms 18 ATP to give a net of 36ATP per glucose
  22. What are the net products of glycolysis?
    • 2 pyruvate 
    • 2 ATP
    • 2 NADH 
  23. What is the net reaction of glycolysis?
    Glucose + 2ADP + 2Pi + 2NAD+ --> 2Pyruvate + 2ATP + 2NADH

    No O2 should be present because remember that glycolysis is independent of O2  
Author
hellosleepy
ID
158819
Card Set
Metabolism
Description
MCAT Biology
Updated

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