Chapter 12.4

Question 1

Is homeostasis and equilibrium the same thing

Answer 1

• no

- >for example, sodium concentrations are much higher outside the neuron than inside but that is all part of homeostasis

Question 2

What is anabolism? What is catabolism?

Answer 2

Anabolism

• > the synthesis of biomolecules
• > occurs after a meal

Catabolism
->the breakdown of biomolecules

Question 3

What are the three major targets for insulin

Answer 3

-they are muscle, adopose tissue and the liver

Question 4

How does insulin affect glycogen storage

Answer 4

• it increases it in the muscles and the liver
• > after glycogen is filled up, the liver converts excess glucose to fatty acids
• > the muscles synthesize proteins and adipose tissue also synthesizes triacylglycerols

Question 5

What two types of cells are insensitive to insulin

Answer 5

-nervous tissue and red blood cells are insensitive to insilin

Question 6

How does the nervous system make energy

Answer 6

-it derives energy from oxidizing glucose to CO2 and water in both the well fed and fasting states

Question 7

How does the red blood cell make energy

Answer 7

• it only uses glucose anaerobically for all the energy needs
• > regardless of t he individual’s metabolic state

Question 8

How does a decrease in insulin and an increase in epinepherine affect amino acid levels in the skeletal muscle and fatty acid levels in adipose tissue

Answer 8

Adipose tissue
->releases fatty acids from the adipose tissue

Skeletal muscle
->releases amino acids from the skeletal muscle

Question 9

Describe the characteristics of fasting, starting with high levels of glucagon and epinepherine

Answer 9

• after about 24 hours, gluconeogenesis is the primary source of glucose
• lipolysis is rapid, resulting in excess acetyl-CoA, which is used in the synthesis of ketone bodies
• once levels of fatty acids are high in the blood, muscle tissue will utilize fatty acids as its major fuel source
• brain will adapt to using ketones for energy

-note cells like red blood cells continue to be dependent on glucose