In chloroplasts, glyceraldehyde 3-phosphate dehydrogenase uses NADPH as a cofactor in the synthesis of glucose. In cytoplasmic gluconeogenesis, however, the isozyme of this dehydrogenase uses NADH.
Why is it advantageous for the enzyme in the chloroplast to use NADPH? :
NADPH is abundant in chloroplasts, because it is generated by the light reactions.
NADPH provides more reducing power than NADH in cells.
NADPH is harmful to chloroplasts when levels become too high.
The presence of NADH increases the rate of wasteful photorespiration.
In chloroplasts, glyceraldehyde 3-phosphate dehydrogenase uses NADPH as a cofactor in the synthesis of glucose. In...
Which of the following sentences is nottrue about alcohol dehydrogenase a. The enzyme uses NADH as cofactor. b. The enzyme transfers the hydride, H- between the substrates. c. If yeast alcohol dehydrogenase is reacted with CH3CD2OH, the generated NADH will contain deuterium in the pro-R position. d. If deuterium NAD+ is reacted with CH3CH2OH, the generated aldehyde will contain deuterium. e. If a pro-R deuterium NADH is reacted with Glyceraldehyde-3-phosphate dehydrogenase, deuterium will be remained in NAD+ Which of the...
Glyceraldehyde-3-phosphate dehydrogenase catalyzes the phosphorylation of glyceraldehyde-3-phosphate, but unlike other glycolytic reactions, it does not require energy investment from ATP. This reaction occurs in two stages: oxidation/reduction and phosphorylation. Why is the oxidation/reduction reaction necessary to make phosphorylation favorable? Choose one: A. The oxidation/reduction reaction is necessary to oxidize phosphate, allowing addition to the substrate. B. The oxidation/reduction reaction is necessary to form an intermediate with a large free energy of hydrolysis. C. The oxidation/reduction reaction is necessary to produce...
NAD+ -dependent Glyceraldehyde-3-phosphate + Dehydrogenase from Thermoproteus tenax. 1. Name the three enzymes that catalyze irreversible, regulated reactions in glycolysis as studied in class. 2. What is the significance of the GAPDH reaction in E. coli to glycolysis? 3. How does the reaction catalyzed by GAPDH from T. tenax presented here differ from the reaction carried out in E. coli? 4. The activity of the GAPDH enzyme was assayed in the presence of a constant amount of glyceraldehyde-3-phosphate and an...
1. According to the paper, what does lactate dehydrogenase (LDH) do and what does it allow to happen within the myofiber? (5 points) 2. According to the paper, what is the major disadvantage of relying on glycolysis during high-intensity exercise? (5 points) 3. Using Figure 1 in the paper, briefly describe the different sources of ATP production at 50% versus 90% AND explain whether you believe this depiction of ATP production applies to a Type IIX myofiber in a human....