nbme 3 S1 Carnitine

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nbme 3 S1 Carnitine

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twesting2173
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09/21/06 - 05:31 PM

oxidation of which of the followoing needs carnatine?

a. acetoacetate
b. ethanol
c. oxaloacetate
d. palmitate
e. pyruvate

i say palmitate. FA's are oxidized to make ATP when energy is depleted. FA are stored as TG...TG get broken into Fatty acids wvia lipolyisis. So now, we've got Fatty acids floating around in the blood...they go to tissue htat are in need of energy...taken up by cells but need ot get into mito inorder to be oxidized (beta oxidation). FA combines with coA to get acyl coA (via coA synthase)....use carnitine shuttle to get in, then undergoes beta oxidation. acetyl goups are made (feed into kreb to make ATP) and also ketone bodies are made. ketoone bodies used by brain in energy starvation.

Edited by new_n_lost on 08/05/07 - 04:52 PM. Reason: mistake

blueocean
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09/21/06 - 06:01 PM

it's palmitate
http://www.indstate.edu/thcme/mwking/fatty-acid-o...

ashfaque
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09/21/06 - 06:14 PM

PALMITATE SURE

young_doc
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09/21/06 - 08:16 PM

I think as far as we're concerned for the Step, Carnitine is ONLY associated with B-Oxidation.

So just look for a F.A. in the answer!

Important to note though is that the Carnitine transport into Mitochondria is ONLY for long and medium-long chain F.A.'s. (Since smaller ones can just diffuse through)

Also important to mention is that this Carnitine transport step is the RATE-LIMITTING STEP OF B-OXIDATION!!! (With (-) feedback via Malonyl-CoA)

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Leopard
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09/21/06 - 08:34 PM

young_doc wrote:
I think as far as we're concerned for the Step, Carnitine is ONLY associated with B-Oxidation.

So just look for a F.A. in the answer!

Important to note though is that the Carnitine transport into Mitochondria is ONLY for long and medium-long chain F.A.'s. (Since smaller ones can just diffuse through)

Also important to mention is that this Carnitine transport step is the RATE-LIMITTING STEP OF B-OXIDATION!!! (With (-) feedback via Malonyl-CoA)

With (-) feedback via Malonyl-CoA)

Are you sure that Malonyl-CoA is formed is formed during beta-oxidation of FA which causes feedback inhibition??

Would you please explain it?/ thanks

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docswapna
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09/21/06 - 09:06 PM

malonyl COA is formed during FA synthesis (not oxidation) and yes its a feedback inhibitor of carnitine transferase enzyme.

young_doc
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09/21/06 - 09:09 PM

Leopold i never said that "Malonyl-CoA is formed is formed during beta-oxidation" ...

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Leopard
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09/21/06 - 10:01 PM

young_doc wrote:
Leopold i never said that "Malonyl-CoA is formed is formed during beta-oxidation" ...

Then what is feedback inhibition ???

A ---(enzyme) ---> B

If the product in any reaction inhibit the enzyme then it is called feedback inhibition . No ???

waiting for your reply

Best of luck

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docswapna
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09/21/06 - 10:09 PM

leopard, ur right. its not feedback. just an inhibitor..

keepgoing
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01/26/07 - 03:10 AM

#10

yes agree with leopard!

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