Question

NADP+ NADPHH HC-OH HO-CH HC-OH нс-ОН CH2OPO;? 6PGDH 'Coz CH OH c=0 HC-OH HC-OH CHOPO3 In pentose phosphate pathway, 6-phosphogluconate undergoes oxidation and decarboxylation by 6- phosphogluconate dehydrogenase (6PGDH) to form D-ribulose 5-phosphate. The reaction generates NADPH, as shown in the scheme. (1) Fill the blanks. During the 6PGDH-catalyzed reaction, the A group of carbon (B) of 6-phosphogluconate is oxidized to the group in ribulose 5-phosphate. A: (name of the functional group). B: (carbon numbering) C: (name of the functional group) (ii) In most animal tissues, glucose is metabolized largely (up to 90%) by glycolysis. However, PPP is dominant in some tissues. Which one of the two tissues has a high PPP activity, skeletal muscle or adipose tissue? Explain your answer. (b) Ribose 5-phosphate labeled with "Cat C-1 is added to a solution containing transketolase (TK). transaldolase (TA), phosphopentose isomerase, phosphopentose epimerase, and glyceraldehyde 3-P. After one tumover of the pathway, two fructose 6-P molecules are formed. Indicate radio-labeling pattern of the second fructose 6-P.

Answer 1

Ans. Functional group is the alcoholic functional group CH-OH (A). Carbon numbering is the second carbon atom (B). Carbonyl functional group (C)

Ans. The adipose tissue would posses more PPP activity as it plays a vital role in the biosynthesis of fatty acids in lactation and in the mammary glands. The NADPH which is generated during the biogenesis is utilised in the adipose tissues.