Thekey differencebetween oxidative and nonoxidative pentose phosphate pathway is thatoxidative pentose phosphate pathway generatesnicotinamide adenine dinucleotide phosphate(NADPH). Meanwhile, nonoxidative pentose phosphate pathway generates戊糖sugars.
戊糖磷酸盐途径是一种平行于糖酵解。它由两种不同的途径组成,作为氧化五戊糖磷酸途径和非氧化戊糖磷酸途径。NADPH是在氧化阶段产生的,而五糖糖是通过非氧化阶段产生的。除五糖糖和NADPH外,该途径还会产生5-磷酸核糖,这是用于的前体nucleotide合成。
内容
1.Overview and Key Difference
2.什么是氧化戊糖磷酸途径
3.什么是非氧化戊糖磷酸途径
4.氧化和非氧化戊糖磷酸途径之间的相似性
5。并排比较 - 氧化与非氧化戊糖磷酸途径以表格形式
6。概括
什么是氧化戊糖磷酸途径?
Oxidative pentose phosphate pathway is the first of two phases of the pentose phosphate pathway. The term “oxidative” has been given to this phase since oxidation takes place in this pathway, and at least one electron is removed in each reaction. The oxidative phase starts with the conversion of glucose 6 phosphate into 6-phosphogluconolactone by an enzyme called glucose 6-phosphate dehydrogenase.
During this conversion, one molecule of NADPH (reducing equivalents) is generated by taking the electron released. Then the 6-phosphogluconolactone transforms into 6-phosphogluconate by 6-phosphogluconolactonase. Finally, the 6-phosphogluconolactonase converts into ribulose 5-phosphate by an enzyme called 6-phosphogluconate dehydrogenase, producing another molecule of NADPH. Therefore, at the end of the oxidative phase, glucose 6 phosphate converts into Ribulose 5-phosphate, producing two molecules of NADPH. NADPH is used in reductive biosynthesis within cells, such as fatty acid synthesis.
什么是非氧化戊糖磷酸途径?
非氧化戊糖磷酸途径是PPT的第二相。核糖5-磷酸(这是氧化相的最终产物)是非氧化戊糖磷酸途径的起始化合物。非氧化相始于通过5-磷酸异构酶和5磷酸核糖5-磷酸核糖5-磷酸磷酸5-磷酸核糖向5-磷酸5-磷酸的转化,并通过5-磷酸盐3-二酰化酶将其转化为5-磷酸。然后,这两种产物通过转酮醇酶转化为3-磷酸甘油醛和7-磷酸乙醛。然后,称为跨化醇酶的酶将它们转化为4-磷酸和6-磷酸果糖的果糖。
最后,木酮糖5-phosphate和赤藓糖4-phosphate are converted into glyceraldehyde 3-phosphate + fructose 6-phosphate by transketolase. The products of the nonoxidative pentose phosphate pathway are used in the synthesis of nucleotides and aromatic amino acids.
氧化和非氧化五磷酸途径之间有什么相似性?
- 氧化和非氧化戊糖磷酸途径是PPT的两个阶段。
- 它们发生在细胞的细胞质中。
- The oxidative phase is followed by a nonoxidative phase.
- ATP is not produced or used in both phases.
- 非氧化阶段使用氧化相的乘积。
What is the Difference Between Oxidative and Nonoxidative Pentose Phosphate Pathway?
The oxidative phase is the first stage of the pentose phosphate pathway in which glucose 6 phosphate is converted into ribulose 5 phosphate by producing NADPH. The nonoxidative phase, meanwhile, is the second stage of pentose phosphate pathway in which ribulose 5 phosphate is converted into fructose-6-phosphate and glyceraldehyde-3-phosphate. So, this is the key difference between oxidative and nonoxidative pentose phosphate pathway. The product of the oxidative phase, the NADPH, helps to build other molecules while the product of nonoxidative phase, ribose-5-phosphate sugar, is used to make DNA and RNA.
Moreover, the overall reaction of oxidative phase is glucose 6-phosphate + 2 NADP++ h2O → ribulose 5-phosphate + 2 NADPH + 2 H++ co2,而非氧化相的总反应为3-核糖-5-磷酸盐→1核糖-5-磷酸 + 2二甲磺糖糖 - 5-磷酸→2果糖-6-磷酸 +甘油醛-3-磷酸。因此,这也是氧化和非氧化戊糖磷酸途径之间的差异。
以下信息图总结了氧化和非氧化五磷酸磷酸途径之间的差异。
概括– Oxidative vs Nonoxidative Pentose Phosphate Pathway
Oxidative and nonoxidative are two distinct phases of the pentose phosphate pathway. Oxidative pathway is the first phase and it is followed by nonoxidative phase. NADPH is produced during the oxidative pentose phosphate pathway and the reactions are not reversible. In contrast, pentoses are produced during the nonoxidative pentose phosphate pathway and the reactions are reversible. Products of the pentose phosphate pathway are useful in different ways. In this regard, ribose-5-phosphate sugar used to make DNA and RNA while the NADPH molecules which help with building other molecules. So, this is the summary of the difference between oxidative and nonoxidative pentose phosphate pathway.
Reference:
1. Berg, Jeremy M. “20.3 The Pentose Phosphate Pathway Generates NADPH and Synthesizes Five-Carbon Sugars.” Biochemistry. 5th Edition., U.S. National Library of Medicine, 1 Jan. 1970,Available here。
2.“戊糖磷酸盐途径。”维基百科,维基梅迪亚基金会,2020年2月25日,Available here。
Image Courtesy:
1. Yikrazuul的“ Ox五戊糖磷酸途径” - 通过Commons Wikimedia
2. Yikrazuul的“ Nichtox Pentosephosphatweg” - 自己的作品(CC BY-SA 3.0)viaCommons Wikimedia
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