Which enzyme acts in the pentose phosphate pathway? <\/p>\n\n\n\n
Select one: <\/p>\n\n\n\n
a. pyruvate kinase <\/p>\n\n\n\n
b. glycogen phosphorylase <\/p>\n\n\n\n
c. 6-phosphogluconate dehydrogenase <\/p>\n\n\n\n
d. phosphofructokinase-1 <\/p>\n\n\n\n
e. aldolase<\/p>\n\n\n\n
The correct answer and explanation is:<\/mark><\/strong><\/p>\n\n\n\n Correct Answer: c. 6-phosphogluconate dehydrogenase<\/strong><\/p>\n\n\n\n The pentose phosphate pathway (PPP), also known as the hexose monophosphate shunt, is a metabolic pathway parallel to glycolysis. It serves two primary functions: generating NADPH and producing ribose-5-phosphate for nucleotide and nucleic acid synthesis.<\/p>\n\n\n\n 6-phosphogluconate dehydrogenase is a key enzyme in the oxidative phase of the pentose phosphate pathway. It catalyzes the oxidative decarboxylation of 6-phosphogluconate to ribulose-5-phosphate, releasing carbon dioxide and producing NADPH in the process. This enzyme plays a central role in maintaining the cell’s reducing environment, especially important in tissues engaged in biosynthetic processes or in cells exposed to oxidative stress.<\/p>\n\n\n\n The PPP begins with glucose-6-phosphate, which is oxidized by glucose-6-phosphate dehydrogenase (G6PD), forming 6-phosphoglucono-\u03b4-lactone and producing one molecule of NADPH. The lactone is then hydrolyzed to 6-phosphogluconate. Next, 6-phosphogluconate dehydrogenase acts on 6-phosphogluconate to form ribulose-5-phosphate and another NADPH molecule.<\/p>\n\n\n\n The NADPH generated is essential for reductive biosynthesis, such as fatty acid and cholesterol synthesis, and for maintaining reduced glutathione levels that protect cells from oxidative damage. Ribulose-5-phosphate produced in the pathway can either enter the non-oxidative phase to generate sugars like ribose-5-phosphate for DNA and RNA synthesis or be recycled back into glycolytic intermediates.<\/p>\n\n\n\n The other options listed are enzymes associated with glycolysis or glycogen metabolism. Pyruvate kinase and phosphofructokinase-1 are part of glycolysis, glycogen phosphorylase breaks down glycogen, and aldolase cleaves fructose-1,6-bisphosphate in glycolysis. Therefore, 6-phosphogluconate dehydrogenase is the correct choice for its specific role in the pentose phosphate pathway.<\/p>\n","protected":false},"excerpt":{"rendered":" Which enzyme acts in the pentose phosphate pathway? Select one: a. pyruvate kinase b. glycogen phosphorylase c. 6-phosphogluconate dehydrogenase d. phosphofructokinase-1 e. aldolase The correct answer and explanation is: Correct Answer: c. 6-phosphogluconate dehydrogenase The pentose phosphate pathway (PPP), also known as the hexose monophosphate shunt, is a metabolic pathway parallel to glycolysis. It serves […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-37465","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/37465","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=37465"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/37465\/revisions"}],"predecessor-version":[{"id":37467,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/37465\/revisions\/37467"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=37465"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=37465"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=37465"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}