Metabolic Pathways involving ATP energy

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fifa
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Metabolic Pathways involving ATP energy

Post by fifa » Wed Sep 23, 2009 5:05 am

I have been struggling with a couple of sample questions we have I know that glycolysis uses ADP and P to form ATP in breaking up glucose. The citric acid cycle uses ADP and GTP to forum ATP and GDP. Also, the electron transport chain uses ADP and P to form ATP. What am I mistaking here since the question doesn't include all of these?

Substrate-level phosphorylation occurs within a metabolic pathway where sufficient energy is released by a given chemical reaction to drive the synthesis of ATP from ADP and phosphate. Substrate-level phosphorylation is seen in which metabolic pathway(s)?
a. glycolysis
b. electron transport chain
c. All of these pathways involve steps where substrate level phosphorylation takes place.
d. citric acid cycle
e. both glycolysis and the citric acid cycle



Also, I am having some problems with understanding some of the cellular respiration reactions. For the respiratory chain, I know the electrons are received from NADH and FADH2. Also, I think the final electron acceptor is oxygen so I think it is all of these. So would all of these be true?

Which of the following is (are) true of the respiratory chain?
a. Electrons are received from NADH and FADH2.
b. Usually the terminal electron acceptor is oxygen.
c. Most of the enzymes are part of the inner mitochondrial membrane.
d. All of these are true about the respiratory chain.
e. Electrons are passed from donor to recipient carrier molecules in a series of oxidation-reduction reactions.

Thank you for your help.

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JackBean
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Post by JackBean » Wed Sep 23, 2009 7:53 am

I think substrate-level phosphorylation is only, when the substrate donates phosphate, am I not right? In that case, only glycolysis is right
Second, TCA definitelly does NOT use ADP and GTP to produce ATP. In citric acid cycle is produced GTP, which can (but does not have to) be converted to ATP, but that's not part of TCA.

I have some doubts about c), I think, all of these enzymes are part of the membrane ;)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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jonmoulton
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Re: Metabolic Pathways involving ATP energy

Post by jonmoulton » Wed Sep 23, 2009 4:49 pm

Look carefully at the citric acid cycle. Do you see a step where a GDP is phosphorylated to form a GTP?

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JackBean
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Re: Metabolic Pathways involving ATP energy

Post by JackBean » Thu Sep 24, 2009 9:03 am

jonmoulton wrote:Look carefully at the citric acid cycle. Do you see a step where a GDP is phosphorylated to form a GTP?


Definitelly! The reaction, where is hydrolyzed succinyl-CoA uses GDP as phosphate acceptor!
http://www.accessexcellence.org/RC/VL/G ... icAcid.jpg
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

david23
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Post by david23 » Sun Sep 27, 2009 3:12 am

for your last question shouldnt choice d all of the above be after e?

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