Metabolism Overview

Question 1

What is metabolism?

Answer 1

chemical reactions and processes occurring in the body

Question 2

What is catabolism?

Answer 2

the process of breaking down large molecules such as phospholipids and proteins into smaller units such as amino acids and fatty acids

Question 3

What is anabolism?

Answer 3

the synthesizing of large molecules from smaller units, using the energy produced by catabolism

Question 4

What are the metabolic features of the liver?

Answer 4

• provides fuel for the brain, muscles and other peripheral organs
• detoxify chemicals
• synthesize bile, ketone bodies, and glucose
• stores glucose

Question 5

What are the metabolic features of the muscles?

Answer 5

• converts chemical energy into mechanical energy by using glucose, fatty acids or ketone bodies

Question 6

What are the three muscles types?

Answer 6

skeletal, striated and cardiac

Question 7

What percent of glycogen is stored in the muscles?

Answer 7

75%

Question 8

What is the difference between how muscles and the liver use glycogen?

Answer 8

muscle glycogen is used mainly in muscle cells while liver glycogen is broken down and released into the blood

Question 9

What are the metabolic features of the brain?

Answer 9

the brain uses synapses to communicate with the body where glucose is the main fuel

Question 10

What is not considered a fuel for the brain?

Answer 10

fatty acids

Question 11

What happens during starvation?

Answer 11

ketone bodies partially replace glucose as the fuel for the brain

Question 12

What tissue stores energy in the form of lipids?

Answer 12

adipose tissue

Question 13

What percent of body fat is stored in adipose tissue?

Answer 13

99%

Question 14

What does adipose tissue produce?

Answer 14

hormones like leptin and estrogen as well as the cytokines such as tumor necrosis factor (promotes insulin resistance….type 2 diabetes)

Question 15

what is the path of blood?

Answer 15

oxygen rich blood pulses from the heart into the aorta, branches into the arteries and enters the capillary network

Question 16

what does the capillary network connect to?

Answer 16

the veins which then carry oxygen poor blood back to the heart

Question 17

What is the main function of the blood?

Answer 17

delivers oxygen to tissues and removes carbon dioxide from the body, transports nutrients and provides a medium to control metabolism

Question 18

The blood glucose levels are mainly controlled by what organ?

Answer 18

liver

Question 19

Ketone bodies are mainly synthesized in the liver but are not utilized as fuels by the liver……. they are utilized where and for what?

Answer 19

brain, muscles, and kidneys for ATP production

Question 20

Where are Thromboxane A2 (TXA2) and prostacyclin (PGI2) produced and what are their functions?

Answer 20

both are 20-carbon fatty acids but TXA2 is produced by platelets and PGI2 is produced by epithelial cells of the artery. TXA2 stimulates platelet aggregation and PCI2 inhibits platelet aggregation

Question 21

Where are bile salts synthesized and stored and secreted?

Answer 21

bile salts are synthesized in the liver and stored in the gallbladder. Once stimulated they are secreted into the small intestines via the bile duct

Question 22

What is the main function of bile salts?

Answer 22

digest dietary fats (triacylglycerols) in the intestines

Question 23

What is the cooperation between the liver and muscles?

Answer 23

muscles have low concentration of the enzyme glucose-6-phosphatase which is needed to convert pyruvate back to glucose but it is abundant in the liver.