Question

The levels of blood glucose are typically maintained around 4-5 mM and the kinetic properties of hexokinase isozymes reflect one means by which this group of enzymes is regulated. Hexokinase II, the hexokinase isozyme present in the adiposecell, has a Km of 0.1 mM. Would glycolysis increase or decrease in the adipose tissue if a mutation were generated in hexokinase II that increased the Km of the isozyme to 50 mM. Briefly explain your answer, including an explanation of the effects of the mutation on the kinetics of the enzyme in regard to blood glucose concentrations. 75 words should be sufficient for your answer.

Answer 1

Hexokinase II is encoded with HK2 gene in chromosome 2.It phosphorylates glucose to produce G6P ,the first step in glucose metabolism called as Glycolysis .It is one of the predominant genes encoded in the skeletal muscles.Any expression or mutation in this gene is insulin responsive.For example if the mutation happens a the hexokinase gene 2 then the insulin responding doesn't occurs systematically and phosphorylation of glucose will be impaired resulting in increased Glycolysis.This alters the ATP productions in the cells.