(a) (b) O (d) (2) If acetyl-CoA were labeled with ¹4℃ at carbonyl group, and then were used as the substrate for the citric acid cycle. Which of the following intermediates would be produced during the first round of the cycle contains the label at the correct position? OH H | | -oc-c-c−CH,-CO2 I I H CO, OH H T O,C-C–C–CH,-CO, I I H CO, OH H II O,C-C–C–CH, CO I T H CO2 OH H `O,C–C–C–CH2-CO I I H CO2 OH H `O,C-C-C-CH2-CO I I H CO,

The citrate cycle is a metabolic engine generating [ Select: "carbon monoxide", "NAD, FAD and GDP", "carbon dioxide, NADH, FADH, and GTP"]   from the fuel  [ Select : "triglycerides", "acetyl-CoA"].  It is considered a cycle since all components must be maintained beginning with the addition of the two carbons from acetyl-CoA to form [ Select ]  ["succinate", "citrate"] from [ Select ]["fumarate", "oxaloacetate"].  The citrate cycle depends on the presence of oxygen since [ Select ]["oxygen is directly required in the citrate cycle", "oxygen is required for NADH and FADH2 oxidation, and their accumulation in the absence of electron transport results in feedback inhibition of the citrate cycle"]            .

Answer A,B,C

The following nutrient molecule is digested and transported to a cell where it undergoes further catabolism: но c-(CH;)14-CH3 di In the table below, list the important products of the complete B oxidation of this molecule. • In the first column of the table, write the chemical formula, name, or standard biochemical symbol for a product molecule. In the second column, write the total number of these molecules produced. • Only list the Important products, including (1) molecules with any of the carbon atoms that were in the original molecule, (2) energy storage molecules (like ATP), and (3) newly oxidized or reduced coenzymes. List each product molecule on a separate row. You can add more rows if you need them. • Be sure you write the number of product molecules formed by the complete B oxidation of the molecule above. • Do not include the products of any catabolic activity that happens before or after B oxidation, including any necessary activation. If the molecule contains small parts…

To oxidize the fatty acid molecule shown below, what enzyme(s) are needed in addition to the enzymes needed for beta - oxidation? A) 2,4- dienoyl-CoA reductase only B) enoyl-CoA isomerase only C) both enoyl-CoA isomerase and 2,4- dienoyl-CoA reductase D) No additional enzymes are needed besides the normal ones for beta - oxidation. CH3(CH2)3-CH=CH-(CH2)3-C-0° по

Refer to Table to explain why FAD rather than NAD+ is used in the succinate dehydrogenase reaction.

Some cofactors that participate in the reactions of the citric acid cycle are indicated by letters. Identify the position of positions of NADH in the cycle by selecting the appropriate letter or letters designating its position(s) in the cycle diagram. COA CH, HO--Co, CH čo, 8 CO но-сн CH HC -Co, CO HO-CH LA Citric acid cycle H,0 co, -B COA | 4 Co, čo D.

1. In a catabolic pathway, metabolite X gets converted into metabolite Y, metabolite X 0 J mol-¹ and AG' is <0 J mol-¹ for this reaction. a) At standard states, is this reaction favorable? b) Is the reaction favorable or unfavorable at cellular condition? c) Is this an endergonic or exergonic reaction in the cell? d) Would you describe this as a thermodynamically downhill or uphill reaction in the cell?

What if C-1 of the oxaloacetate were labeled instead, when would the label be released as CO2?

[methyl-14C]Pyruvate was administered to isolated liver cells in the presence of sufficient malonate to block succinate dehydrogenase completely. After a time, isocitrate was isolated and found to contain label in both carbon 2 and carbon 5: How do you explain this result?