Where in the body is Glycogen mainly stored?

In the liver and muscles

What are the two types of glucose polysaccharide linkages?

alpha(1->4) makes long chains

alpha(1->6) makes branches

The more _____ ends you have, the ______ you build up and break down glucose

More, quicker

Glycogen Metabolism

-Review slide 4 and practice drawing the mech?

When does glycogen breakdown happen?

During the four Fs and low blood sugar

What is phosphorolysis?

Using a phosphate to break a bond

This enzyme cleaves an alpha (1->4) linkage from nonreducing ends. Product is a glucose 1-phosphate

Glycogen phosphorylase

What is the difference between Phosphatase and Phosphorylase?

Phosphatase removes the Phosphate

Phosphorylase uses phosphate to cleave a bond

This enzyme removes G1P until 3-4 residues away from an alpha (1->6) branch point.

Glycogen phosphorylase

Describe the steps of the debranching enzyme

-A transferase transfers the last 3 residues to the nonreducing end of the longer chain

-A glucosidase hydrolyzes an alpha(1->6) linkage to cleave off the glucose

This enzyme catalyzes a reversible isomerization from G1P to G6P

Phosphoglucomutase

What happens when there is lots of glucose and ATP?

Glycogen Synthesis

What are the steps to Glycogen Synthesis

Phosphoglucomutase (Activation), Glycogen synthase (Elongation), Glycogen branching enzyme (Branching),

What is Glycogenin?

A protein with Tyrosine residue which adds the Tyr, adds 6-7 more UDP glucose and adds branching

Name the regulation when one pathway is on while the opposite is off

Reciprocal regulation

Which regulation has G6P determine what is on and off

Allosteric Regulation

In covalent modification...

Phosphorylation of glycogen phosphorylase: on

Phosphorylation of glycogen synthase: off

Glycogen Phosphorylase is in the R state when Glycogen Phosphorylase is _____

On

What hormones do Glycogen Phosphorylase activate?

Glucagon and Epinephrine

Explain the different types of Muscle fibers

Slow twitch muscles are good for endurance while fast twitch muscles are good for sprinting short distances. Can be tested by just running and seeing how you feel