Comparing rates of CO2 generation in two pathways

Hey OTA's, A fourth pathway question. This question requires an understanding of the fate of carbon at the C1 and the C6 on glucose in each of these two pathways. I am tracing CO2 through each of the 2 pathways with colored pencils tonight. Seeing how to do this (with any explanations you might be able to provide on how you have gone about it) would be excellent. 4. The relative metabolic activities in an organism of glycolysis + the citric acid cycle vs. the pentose phosphate pathway + gluconeogenesis can be measured by comparing rates of 13CO2 generation upon administration of glucose labeled with 13C at C1 with that of glucose labeled at C6. Explain why this is possible... se... click for more

ATP production at two different steps in ox. phos.

5. Why is the oxidation of succinate to fumarate only associated with the production of two ATPs during oxidative phosphorylation, whereas the oxidation of malate to oxaloacetate is associated with the production of three ATPs?

Mitochondrial membrane and free energy release

Hello OTA's, This is a basic mitochondrial membrane question. I am struggling with calculating free energy release (as protons are transported across the membrane). I havn't been able to come up with an attack for this via google. I am hoping to find out how this example is done and what form the answer should be in. This problem is not graded and has no posted answer key: your explanations/justifications for your answer are very valuable to me.

13C as a label for metabolites in NMR spec.

Hello OTA's, Of all the basic 13C problems I am working through, this has been the most challenging for me. I made a break through find online last night: I found the original article that I believe this question was formed from. There is no answer and no grade on this problem. Its a test of following C and backing up what the NMR results claim. So far this one has been quite difficult. I have attached the link to the paper I found in this attachment (my inderstanding of NMR is basic, so this may be oversimplified for you). I would really benefit from hearing how you approached this one.

Following C in ingested acetate to a triglyceride

Hello OTA's, This is the last of the first set of representative problems I will be posting this week. It is a 14C problem tracing C from an ingested acetate to a newly synthesized triglyceride in an animal. It requires structural justification for the answer. This problem has no set answer but is a representative of a set of 9 like-problems. As a first taste of this kind of problem, I am hoping to have as much general justification in each step as possible.