Question

CH OH OH OPO OH 2-O,POH, CH2OH CHOPO,2- KHHO How OH HO H HO OH OHHO- но и OH Glucose 6-phosphate (G-6P) нон CH OH KOH LOH OH A. (10 pts) Name the enzymes catalyzing the four numbered metabolic steps and identify the product of that metabolic step in each case. B.1. (6 pts) Under what metabolic conditions would most of the Glucose 6P go through route #1, and not the other alternative routes? (Indicate what is going on in the circulating blood) 2. (8 pts) Under what metabolic conditions would both routes 2 and 4 be maximally active? Succinctly describe what the liver is doing physiologically under these conditions, and in a sentence, what is going on with other organs.

Im Looking for Part B. 1 And 2 specifically. Thanks!

Answer 1

B.

1 Glucose 6 phosphate can be converted to Glucose when there is lack of glucose in the blood. Then route 1 predominates. Glucose 6 phosphatase converts glucose 6 phosphate to glucose which goes to blood and increase blood glucose level.

2.  Route 2 that is Glucose 6 phosphate to Fructose 6 phosphate is the step of glycolysis. When cells require energy, glucose is converted to pyruvic acid which then enters TCA cycle and ultimately ATPs are produced through Electron trasport chain.  In the gycolysis , glucose 6 phosphate is first converted to Glucose 1 phosphate and then glucose 1 phosphate is converted to Fructose 6 phosphate by phosphogluco isomerase enzyme. So during energy need of the body this pathway predominates.

Route 4 that is glucose 6 phosphate to 6 phospho glucono delta lactone is the initial step of pentose phosphate pathway. PP pathway is predominat when cells need nucleotide synthesis and NADPH for that reaction in huge amount. Nucleotide synthesis occurs mostly in rapidly dividing tissues , for eg. skin, gastric mucosa and bone marrow.