Page 10 - Chapter 3: Cells and Tissues

6O 2 + C 6H 12O 6 6CO 2 + 6H 2O + 38 ATP

c. Glycogen
Glycogen is the storage form of glucose. It is a highly branched
polysaccharide that is called animal starch.

Glycogen is stored primarily in the liver and skeletal muscles.
When blood glucose levels decrease, the liver can break down
glycogen into glucose and release the glucose into the blood.
When blood glucose levels increase, the liver can convert and
store glucose as glycogen.

d Three uses of glucose.

Glucose can be used immediately for fuel.
Glucose can be converted to and stored as glycogen and used at
a later time for fuel or in the regulation of blood glucose levels.
Glucose can be converted to and stored as fat for use as a fuel at
a later time.
i. Anaerobic metabolism… glycolysis (A) yields very little ATP,
since glucose is not completely broken down. Most of the
energy is still tied up in lactic acid. Glycolysis is the
anaerobic catabolism of glucose to lactic acid. The end
product of glycolysis is lactic acid and a few ATP molecules.
Glycolysis occurs within the cytoplasm.

Aerobic metabolism yields a lot of ATP, since glucose is
completely metabolized.

v. The end products of aerobic metabolism

The aerobic catabolism of glucose yields CO 2 + water + ATP.
Aerobic catabolism occurs within the mitochondria.

The Krebs cycle enzymes are located within the mitochondria.
A deficiency of O 2, as in shock, cause a shift from Krebs cycle
activity to glycolysis
Shock results in a lack of oxygenation of the cells. Therefore anaerobic
metabolism (glycolysis) can occur but aerobic metabolism cannot
operate without oxygen.