glucose - glycolisis

[victor]

You mean that when entering glycolysis fructose is directly changed into fructose-6-phosphate??(directly to the 3rd substrate of glycolysis?)

Wow...spermatozoa likes a sweeter things... ..fructose is 1.7x sucrose while glucose is only 0.67x sucrose..

[Dr.Stein]

This is the steps of glycolisis in spermatozoa (also called as fructolysis):

1. fructose ---> fructose-1-phospate by kinase
2. fructose-1-phospate ---> fructose-1,6-diphospate by kinase
3.fructose-1,6-diphospate ---> 2 triosephosphates (3-phospho-glycerine aldehyde & dihydroxyacetone phosphate) by aldolase
4. 3-phospho-glyceraldehyde ---> 1,3-diphosphoglycerine by replacing H+, reaction with anorganic phosphate, dehydrogenase, diphosphopyridine nucleotid/DPN-DPNH2 ---> 1,3-diphosphoglycerat
5. 1,3-diphosphoglycerat ---> 3-phosphoglycerat by phosphatase
6. 3-phosphoglycerat ---> 2-phosphoglycerat by mutase (phosphoglyceromutase)
7. 2-phosphoglycerat ---> phosphoenolpyruvat by enolasem transphosphorylase
8. phosphoenolpyruvat ---> pyruvat by phosphatase
9. pyruvat ---> lactat (DPNH2-DPN)

It is stated that spermatozoa prefer to undergo fructolysis in aerobic pathway (using lactat).

[xenthe]

what's the meaning by beta-chain and alfa-chain ?What's the different between them?

[victor]

First, see the differences between thw 2 structures of Maltose and cellobiose. You'll see that both of them have nearly the same structure (because they come from the same monomer: glucose). The differencec is that Maltose has an alpha glycosidic bond in the C-1 and C-4. While cellobiose has the beta glycosidic bond..
confused? same with me then.. ok, to make it clear, I'll post their photo.

[teyya]

hi all.i need to ask some questions...because it was asked by my lecture...in glycolysis process,why glucose cannot be phosphorylated two times and directly converted to glucose-1,6 biphosphate instead of fructose 1,6 biphoshpate..and secondly, can galactose be transformed to fructose? i need ur help......