Friday March 5, 1999
Announcements: Have a good Spring Break.

Lecture notes:

Complex carbohydrates are broken down and the glucose is released slowly into the blood stream.

Simple carbohydrates are absorbed rapidly into the blood stream, no digestion needed.

The presence of glucose in the blood stream causes the release of insulin from the endocrine cells in the pancreas.

Insulin causes increased uptake of glucose by cells.

What is the Fate of glucose in cells?

Liver: glucose is made into glycogen, or amino acids, or fats, or energy.

Fat cells: glucose is used for fat production or energy.

Muscle cells: glucose is made into energy or glycogen.

Others: glucose is made into energy.

This restores the normal blood glucose level.

Digested fats become 3 fatty acids and glycerol. The transport of fats and cholesterol in the blood is complicated and involves phospholipid/protein carriers. (chylomicron, HDL, LDL, VLDL)

Fatty acids are taken up by adipose cells, liver and muscle mainly.

Glycerol goes to the liver to be metabolized.

Adipose cells……………………………………………………………………..stored as fat (triglycerides)

Muscle………………………………………………………………………… used for energy

Liver…………………………………………………………………………… Used for energy, converted to
triglycerides changed to other
molecules.

Proteins are broken down into amino acids when digested

1. These amino acids can be used by cells to make cell proteins or plasma proteins.
2. They can be made into other nitrogen derivatives.
3. They can be turned into fats or carbohydrates.
4. Some amino acids can be converted into other amino acids.

• Excess protein is turned into fat or carbohydrate which is either used or stored. There is no storage protein.

2. This occurs only if the membrane threshold is met. "The stimulus must be of sufficient strength and/or duration to depolarize the trigger zone.) If not, there is only a local depolarization.