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- May 22, 2011
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Passage about glycolysis, it also include the possible fermentation to alcohol or lactate production.
If one molecule of glucose were radioactively labeled with 14C at the C-4 position, then which of the following metabolic intermediates would show the 14C label?
A. DHAP and lactate
B. DHAP and ethanol
C. Lactate and carbon dioxide
D. DHAP, lactate, and carbon dioxide
Answer is C.
I understand the reasoning why DHAP would not have a labeled carbon if its coming from Fructose 1,6-bisphosphate .
My issue is, wouldn't DHAP gain a labeled carbon because of the inter-conversion between glyceraldehyde 3-phosphate and DHAP? (since that reaction has a Delta G pretty close to zero the conversions will always be occurring throughout the process of glycolysis.) or should I think of glycolysis in more simplistic terms of just one glucose going down the chain.?!
My other problem is about carbon dioxide. Is it considered as an intermediate metabolite?!!! I always thought of it as an end result, and not as an "intermediate".
Thank you
If one molecule of glucose were radioactively labeled with 14C at the C-4 position, then which of the following metabolic intermediates would show the 14C label?
A. DHAP and lactate
B. DHAP and ethanol
C. Lactate and carbon dioxide
D. DHAP, lactate, and carbon dioxide
Answer is C.
I understand the reasoning why DHAP would not have a labeled carbon if its coming from Fructose 1,6-bisphosphate .
My issue is, wouldn't DHAP gain a labeled carbon because of the inter-conversion between glyceraldehyde 3-phosphate and DHAP? (since that reaction has a Delta G pretty close to zero the conversions will always be occurring throughout the process of glycolysis.) or should I think of glycolysis in more simplistic terms of just one glucose going down the chain.?!
My other problem is about carbon dioxide. Is it considered as an intermediate metabolite?!!! I always thought of it as an end result, and not as an "intermediate".
Thank you
