biochem

From: Hugh Janus (HughJanus_at_bigfoot.com)
Date: 10/20/04 

Date: Wed, 20 Oct 2004 22:56:23 +1300

 was wondering if anybody could be kind enough to help me answer some
questions. I would look them up myself but are a bit stretched for time so
please help me.

1. What does it mean that the enzyme phospofructokinase is a control point
in glycolysis?

Does it have anything to do with that it is the primary site for regulation
of the flow of carbon through glycolysis.

2. Extracellular glucose is phosphorylated on entering the cell at position
6. Glucose from cellular glycogen stores is converted to
glucose-1-phosphate. G-1-P is then converted into G-6-P. Why does the cell
have to mechanisms for glucose phosphorylation?

Has this to do with that G-1-P comes from Galactose and G-6-P comes from
other sugars.

3. Glucose is phosphorylated to glucose-6-phosphate by two enzymes,
glucokinase and hexokinase. State the difference between these two enzymes.

Glucokinase in the liver and have a high Km (sorry about the m) value, and
its insensitive to inhibition by G-6-P.
Hexokinase muscle, low Km value.

Really appreciate some help.
Thanks V

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