Question

Short answer questions, answer on blank paper. These questions cannot be answered without work, you must show all work for full credit. 1. (8 points) Given the following metabolic pathway of aspartate to pyruvate, all of which occurs in the cytosol thus requiring transport of electrons into the mitochondria, calculate the number of ATP that can produced from the complete cxcidation of aspartate in the muscle aspartate oxaloacetate m NAD NADH NADH NAD alate Pyruvate NAD NADH 2. (7 points) The production of sucrose in a plant requires one molecule of glucose-6-phosphate and one molecule of fructose-6-phosphate. In order to form the glycosidic bond between the two monosaccharides, one molecule of ATP is required (Glucose-6-phosphate and fructose-6. phosphate are easily interconverted by a process that requires no energy). How many molecules of CO2, NADPH, and ATP are required for the production of sucrose in sugarcane, a C4 plant? 2. (10 points) Hemp oil contains eicosenoic acid (20:189) as its primary monounsaturated fatty acid. Consider a situation where eicosenoic acid was used for the production of 6- hydroxybutyrate through the processes of p-oxidation followed by the reaction soon below. 2 acetyl COA Z B -hydroxybutyrate NADH NAD What are the B-oxidation products of one molecule of eicosenoic acid? How many molecules of B-hydroxybutyrate can be produced from one molecule of eicosenoic acid? Considering the requirements for 3-hydroxybutyrate production and that any excess NADH and FADH2 will proceed to electron transport, how many ATP can be produced from a molecule of cicosenoic acid being converted into 3-hydroxybutyrale (use the typical amounts of ATP production) 4. (15 points) The hormone cortisol causes activation of pathways that under normal conditions are not active at the same time. Cortisol increases muscle breakdown for the purpose of converting amino acids into onergy storage. One way this is done is by using gluconeogenesis to convert the carbon from amino acids into glucose-6-phosphate, which is then stored as glycogon (the conversion of glucose-6-phosphate to a residue of glucose in glycogon requiros 1 ATP equivalent). Consider a situation where arginine from muscle was transported to the liver and used as the starting amino acid for storage of glucose as glycogen

Answer 1

1. Total number of ATP produced in aerobic respiration where glucose is completely burnt to give rise to CO2, H2O and energy is 32 ATP molecules. It involves 3 steps. 1. Glycolysis, 2. Decarboxylation of pyruvate to acetyl CoA 3. TCA cycle 4. ETC.

The link reaction, TCA and ETC produce, 8 NADH, 2 FADH2 and 2 ATP. Each of NADH produces 2.5 ATP and FADH2 produces 1.5 ATP.

Net gain from NADH-----------8 x 2.5= 20 ATP

Net gain from FADH2 ------------2 x 1.5 = 3 ATP

ATP produced --------------------------------=2 ATP

Total from link reaction, TCA and ETC we get 25 ATP.

When Aspartate is getting converted to pyruvate, we get net gain of 1 NADH. There 2 NADH produced and one is consumed while converting aspartate to pyruvate , so net gain is 1 NADH. The electrons from NADH need to be transported in to matrix of mitochondria for generating ATP. Transport needs some energy. So net gain from each NADH produced in cytosol is only 1.5 ATP. So 25 + 1.5= 26.5 ATP is the net gain of ATP when aspartate is completely oxidized.