Which enzyme of the ones shown below generates the first intermediate compound with a high phosphoryl‑transfer potential that is not ATP

Question

Which enzyme of the ones shown below generates the first intermediate compound with a high phosphoryl‑transfer potential that is not ATP

BlackTom AI · Accepted Answer

To determine which enzyme generates the first intermediate with high phosphoryl-transfer potential that is not ATP, we need to trace glycolytic steps and the nature of the high-energy intermediates formed.
Option 1: aldolase. This enzyme splits fructose-1,6-bisphosphate into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. While it is a key glycolytic enzyme, the reaction does not produce a high-energy phosphate compound itself; it simply cleaves a fructose-bisphosphate to generate triose phosphates. Therefore this option does not describe the generation of a high-energy phosphorylated intermediate.
Option 2: hexokinase. This enzyme catalyzes the phosphorylation of glucose to glucose-6-phosphate using one ATP molecule, introducing a phosphate and consuming ATP. The product is glucose-6-phosphate, which is a phosphorylated sugar, but it is not characterized by a high phosphoryl‑transfer potential intermediate formed in the subsequent steps; furthermore, the question asks for the first intermediate with high phosphoryl-transfer potential that is not ATP, which points to a later step after the initial ATP investment.
Option 3: glyceraldehyde 3-phosphate dehydrogenase. This enzyme oxidizes glyceraldehyde-3-phosphate and adds an inorganic phosphate to form 1,3-bisphosphoglycerate. This reaction produces a high-energy acyl-phosphate intermediate (1,3-bisphosphoglycerate) with a high phosphoryl-transfer potential and, importantly, it is not ATP itself. The appearance of this intermediate represents the first instance in glycolysis of a high-energy phosphate-bearing compound that is not ATP, aligning with the question’s specification.
Option 4: phosphoglucose isomerase. This enzyme converts glucose-6-phosphate to fructose-6-phosphate, an isomerization step. It does not generate any high-energy phosphate-containing intermediate; it merely rearranges the carbonyl and hydroxyl positions. Consequently, it does not meet the criterion of forming a high-energy phosphoryl-transfer intermediate.
In summary, among the listed enzymes, the step catalyzed by glyceraldehyde 3-phosphate dehydrogenase uniquely generates 1,3-bisphosphoglycerate, a high-energy phosphoryl-transfer intermediate that is not ATP, whereas the other options either do not generate such an intermediate or are involved in earlier ATP-dependent phosphorylation or non-energetic rearrangements.

Which enzyme of the ones shown below generates the first intermediate compound with a high phosphoryl‑transfer potential that is not ATP

查看解析

登录即可查看完整答案

类似问题

What is the function of glyceraldehyde 3-phosphate dehydrogenase?

What reaction is catalyzed by aldolase?

What two 3-carbon molecules are generated by the cleavage of fructose-1,6-bisphosphate?

Which of the following must be regenerated for glycolysis to proceed?

Which of the following is not an intermediate in the glycolytic pathway by which glucose is oxidized to pyruvate

Which of the following glycolytic reactions constitutes a major thermodynamic driving force for glycolysis in vivo

Which of the following best describes the net organic products formed during the oxidation of one molecule of glucose to two molecules of pyruvate via glycolysis

If glucose is labeled with 14C at the C1 position only, which of the following would occur if the glucose underwent glycolysis? Hint: Open chain form of Glucose has an aldehyde group at C1

更多留学生实用工具

考试浏览器助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单