I just need help with part B, this question has been posted by others but the an
ID: 999704 • Letter: I
Question
I just need help with part B, this question has been posted by others but the answers were wrong. It is NOT all of the the H's. Please explain if you know the correct answer, thanks
You are investigating the incorporation of deuterium from [2-2H]acetyl-CoA (all hydrogen atoms replaced by deuterium) into palmitic acid with two different enzyme systems as described below. Predict which hydrogen atoms of palmitic acid will be deuterium-labeled in each system by clicking on each hydrogen that will be labeled. (Selected hydrogens will turn green. You can deselect by clicking a second time. Be careful to select only H atoms, and not bonds.)
You are investigating the incorporation of deuterium from [2-Hacetyl-CoA (all hydrogen atoms replaced by deuterium) into palmitic acid with two different enzyme systems as described below. Predict which hydrogen atoms of palmitic acid will be deuterium-labeled in each system by clicking on each hydrogen that will be labeled. (Selected hydrogens will turn green. You can deselect by clicking a second time. Be careful to select only H atoms, and not bonds.) (a) The enzyme system contains fatty acid synthase, NADPH, and unlabeled malonyl-CoA. D O DC-C-S-COA S-CoA (b) The enzyme system contains fatty acid synthase, acetyl-CoA carboxylase, NADPH, ATP, and HCO3. D O u have part (a) correct, but part (b) is incorrect. From part (a), you know that the hydrogen atoms of C-16 are labeled. Now you need to determine which atoms are derived from the hydrogen atoms of malonyl-CoA. Acetyl-CoA carboxylase catalyzes the formation of malonyl-CoA from acetyl-CoA and HCO3Explanation / Answer
Not all hydrogen atoms will be labeled with deutirium because when we use the reagents stated in part b, then acetyl-CoA is used to synthesize malony-CoA which then reacts with a acetyl-CoA to form palmatic acid. It takes 7 malonyl-CoA to react with 1 acetyl-CoA to form the desired product and one carbony carbon is taken from each malonyl-CoA along with -CH2- group. So starting with the terminal methyle group, terminal methyl group will be labeled, the -CH2- next to it will be labeled after which alternate grops would be labeled i.e. the 3rd carbon from the right will have unlabeled hydrogen, the 4th carbon from the right will again have labeled carbon, the next carbon hydrogen unlabeld and so on till we reach the carboxylic group.