3. Tissue/Organ and Overview of Metabolism

Question 1

metabolism

Answer 1

chemical reactions and processes occurring in the body

Question 2

2 categories of metabolism

Answer 2

catabolism + anabolism

Question 3

catabolism

Answer 3

breaks down large molecules into smaller units

Question 4

anabolism

Answer 4

synthesizes large molecules from small units by using energies produced in catabolism

Question 5

most important organ for metabolism in body

Answer 5

liver

Question 6

where does the liver provide fuel

Answer 6

brain, muscle + other peripheral organs

Question 7

functions of liver

Answer 7

• help digest, absorb and process food
• detoxifies chemicals and metabolizes drugs
• stores glucose in form of glycogen

Question 8

what does the liver synthesize?

Answer 8

bile acids
glucose
ketone bodies
VLDL
cholesterol
triacylglycerols
phosphoglycerides

Question 9

how does the liver utilize glycogen

Answer 9

break down glycogen to release glucose -> blood glucose is used as energy fuels by many different tissues => controls blood glucose level

Question 10

function of muscle

Answer 10

major biochemical transducer that converts chemical energy into mechanical energy

Question 11

muscle - major fuels

Answer 11

glucose, fatty acids + ketone bodies

Question 12

major glycogen storage in body?

Answer 12

muscle

Question 13

what is glycogen converted to in muscle?

Answer 13

glucose-6-phosphate for use within the muscle cells

Question 14

fuel for brain?

Answer 14

glucose

Question 15

when are ketone bodies used in the brain?

Answer 15

during prolonged starvation, ketone bodies partly replace glucose as fuel for the brain

Question 16

how does adipose tissue store energy?

Answer 16

in the form of lipids

Question 17

what does adipose tissue produce?

Answer 17

hormones (leptin + estrogen) and cytokines

Question 18

what fuel do RBCs use?

Answer 18

glucose as energy fuel

Question 19

function of blood

Answer 19

• deliver oxygen to tissues and remove carbon dioxide from the body
• transport nutrients

Question 20

where are ketone bodies synthesized?

Answer 20

liver

Question 21

why are ketone bodies not used in the liver?

Answer 21

livers lack the enzyme thiotransferase

Question 22

what are ketone bodies used for?

Answer 22

ATP production by brain, muscle and kidney

Question 23

Thromboxane A2 (TXA2): where is it produced and what does it do

Answer 23

produced by platelets and stimulates platelet aggregation

Question 24

Prostacyclin (PGI2): where is it synthesized and what does it do

Answer 24

synthesized by endothelial cells of the artery and it inhibits platelet aggregation

Question 25

where are bile acids synthesized and stored?

Answer 25

synthesized in the liver and stored in the gall bladder

Question 26

where are bile acids secreted?

Answer 26

small intestine

Question 27

why are bile acids important?

Answer 27

bile acids are required to digest dietary fats in the intestine

Question 28

why are muscles unable to convert pyruvate back to glucose

Answer 28

they have extremely low conc. of glucose-6-phosphate

Question 29

where is glucose-6-phosphate abundant?

Answer 29

liver