Chapter 26

(a) Identify 6 -phosphglucono- \(\delta\) -lactone.______________ (b) Which reactions produce NADPH?_______________ (c) Identify ribulose 5 -phosphate.______________ (d) What reaction generates \(\mathrm{CO}_{2}\) ?___________ (e) Identify 6 -phosphogluconate.____________ (f) Which reaction is catalyzed by phosphopentose isomerase?______________ (g) Identify ribose 5 -phosphate_____________ (h) Which reaction is catalyzed by lactonase?______________ (i) Identify glucose 6 -phosphate.______________ (j) Which reaction is catalyzed by 6 -phosphogluconate dehydrogenase?_______________ (k) Which reaction is catalyzed by glucose 6 -phosphate dehydrogenase?______________ (EQUATION CAN'T COPY)

The pentose phosphate pathway is composed of two distinct phases. What are the two phases, and what are their roles?

What is the key regulatory enzyme in the pentose phosphate pathway, and what is its most prominent regulatory signal?

Noted psychiatrist Hannibal Lecter once remarked to FBI Agent Starling that he enjoyed liver with some fava beans and a nice Chianti. Why might this diet be dangerous for some people?

Liver and other organ meats contain large quantities of nucleic acids. In the course of digestion, RNA is hydrolyzed to ribose, among other chemicals. Explain how ribose can be used as a fuel.

Glucose labeled with \(^{14} \mathrm{C}\) at \(\mathrm{C}-6\) is added to a solution containing the enzymes and cofactors of the oxidative phase of the pentose phosphate pathway. What is the fate of the radioactive label?

Why do deficiencies in glucose 6-phosphate dehydrogenase frequently present as anemia?

Explain why the Calvin cycle and the pentose phosphate are almost mirror images of each other.

Which reaction in the citric acid cycle is most analogous to the oxidative decarboxylation of 6 -phosphogluconate to ribulose 5 -phosphate?

Red blood cells lack mitochondria. These cells process glucose to lactate, but they also generate \(\mathrm{CO}_{2}\). What is the purpose of producing lactate? How can red blood cells generate \(\mathrm{CO}_{2}\) if they lack mitochondria?

Ribose 5 -phosphate labeled with \(^{14} \mathrm{C}\) Eat \(\mathrm{C}-1\) is added to a solution containing transketolase,transaldolase, phosphopentose epimerase, phosphopentose isomerase, and glyceraldehyde 3 -phosphate. What is the distribution of the radioactive label in the erythrose 4-phosphate and fructose 6 -phosphate that are formed in this reaction mixture?