Chapter 16 Regulation of Organic Metabolism and Energy Balance

Question 1

• This is the period immediately following a meal during which high levels of carbohydrates, lipids and proteins are being absorbed from the small intestines.
• Each nutrient is processed somewhat differently.

Answer 1

Absorptive State

Question 2

Most carbohydrates are absorbed as by the small intestines.

Answer 2

glucose

Question 3

Most of the glucose is stored in the and muscles as glycogen.

Answer 3

liver and skeletal

Question 4

a polymer made up of many glucoses linked together.

Answer 4

Glycogen

Question 5

found in sucrose and high fructose corn syrup.

Answer 5

Fructose

Question 6

• This is the period between meals when nutrients are not being absorbed from the intestines.
• Net synthesis of glycogen, fat, and protein ceases and net catabolism of all these substances begins.
• The major goal of postabsorptive functions is to keep the glucose level in the plasma in the normal range so that the nervous system has a steady energy supply.

Answer 6

Postabsorptive State

Question 7

glycogen can be broken down

Answer 7

Glycogenolysis

Question 8

new glucose is made from the carbon skeletons of amino acids (or from glycerol, pyruvate, or lactic acid).

Answer 8

Gluconeogenesis

Question 9

most tissues can use fatty acids to make ATP so glucose is spared for the brain.

Answer 9

Glucose sparing

Question 10

Adipose cells break triglycerides down to free fatty acids and glycerol and release them into the blood.

Answer 10

Lipolysis

Question 11

major energy source for most body tissues (other than the brain and RBCs) when oxygen is plentiful.

Answer 11

Free fatty acids

Question 12

When the rate of fatty acid breakdown in the liver produces more ATP than is needed by the liver cells, the excess acetyl CoA is converted

Answer 12

into ketone bodies,

Question 13

In diabetes mellitus or during starvation, the amount of ketone bodies in the blood can increase to dangerous levels.

Answer 13

ketoacidosis

Question 14

Absorptive and Postabsorptive States

Answer 14

These states are controlled by:

1. The balance between insulin and glucagon
2. The balance between the sympathetic and parasympathetic systems
3. Other hormones like cortisol and growth hormone

Question 15

responsible for the majority of the events that occur in the absorptive state.

Answer 15

Insulin

Question 16

Made by alpha cells of the pancreatic islets.

Secreted in response to low plasma glucose levels.

Answer 16

Glucagon

Question 17

Effects of glucagon

Answer 17

• Increases the blood glucose level by stimulating the breakdown of glycogen to glucose in the liver (glycogenolysis). This provides glucose for brain cells.
• Promotes the formation of new glucose from glycerol and amino acids (gluconeogenesis) by the liver.