1. SDN Mobile is now free on iTunes and on the Google Play Store. Enjoy!
    Dismiss Notice
  2. Hey Guest! Check out the 3 MCAT Study Plan Options listed in the 'stickies' area at the top of the forums (BoomBoom, SN2ed, and MCATJelly). Let us know which you like best.

    Also, we now offer a MCAT Test-Prep Exhibitions Forum where you can ask questions directly from the test-prep services.
    Dismiss Notice
  3. This forum is for support and discussion only. Please promote test prep materials/services (including AMAs) in the Special Offers subforum only. Thanks!
    Dismiss Notice
Dismiss Notice

Interview Feedback: Visit Interview Feedback to view and submit interview information.

Interviewing Masterclass: Free masterclass on interviewing from SDN and Medical College of Georgia

Movement of H+ in mitochondria

Discussion in 'MCAT: Medical College Admissions Test' started by 4s4, Aug 7, 2006.

  1. 4s4

    4s4 Member
    2+ Year Member

    Joined:
    Jun 10, 2006
    Messages:
    168
    Likes Received:
    0
    Status:
    Pre-Medical
    I'm kind of confused about the whole electron transport chain business and chemiosmotic theory. Is the movement of H+ from the intermembrane space to matrix DOWN the gradient or against? This came up on Kaplan 6 BS and I'm not really getting their explaination. Thanks!
     
  2. BigRedPremed

    BigRedPremed Senior Member
    7+ Year Member

    Joined:
    Jul 20, 2005
    Messages:
    1,437
    Likes Received:
    2
    Status:
    Pre-Medical
    It should be down the gradient.
     
  3. OP
    OP
    4s4

    4s4 Member
    2+ Year Member

    Joined:
    Jun 10, 2006
    Messages:
    168
    Likes Received:
    0
    Status:
    Pre-Medical
    If it's down...then ATP synthesis occurs according to the passage by the "re-entry of protons into the matrix" so when H+ goes down the gradient, then ATP is made...so why does the question (#152) say that "Nigericin is an agent that carries H+ down its concentration gradient" and the answer is that bacteria will be less efficient in making ATP? Shouldn't they be MORE efficient at making ATP?
     
  4. BigRedPremed

    BigRedPremed Senior Member
    7+ Year Member

    Joined:
    Jul 20, 2005
    Messages:
    1,437
    Likes Received:
    2
    Status:
    Pre-Medical
    Um, I took the MCAT a year ago and don't know the exact passage you are referencing. My guess is that it would destroy the H+ gradient that is needed to generate ATP. Remember, that ATP is only generated when H+ flows down its gradient THROUGH ATP synthase. If there is a drug that moves H+ down the gradient w/o having to pass through the synthase, you get a reduced gradient w/o generating any ATP. Just my guess.
     
  5. Sol Rosenberg

    Sol Rosenberg Long Live the New Flesh!
    Physician 10+ Year Member

    Joined:
    Feb 11, 2006
    Messages:
    3,534
    Likes Received:
    7
    Status:
    Attending Physician
    Good guess. That is the reason.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  6. OP
    OP
    4s4

    4s4 Member
    2+ Year Member

    Joined:
    Jun 10, 2006
    Messages:
    168
    Likes Received:
    0
    Status:
    Pre-Medical
    Ohhh, makes sense. Thanks!
     
  7. Foolins

    Foolins Member
    2+ Year Member

    Joined:
    May 4, 2006
    Messages:
    101
    Likes Received:
    0
    Status:
    Other Health Professions Student
    Because in the mitochondria, the only route for H+ down its gradient should be the channels coupled to ATP synthase.

    If you had some another way of transporting H+ down its gradient without going through the ATP synthase...then it would go back into the matrix for nothing.
     

Share This Page