Fatty Acid Synthesis

Question 1

does eating fat stimulate fat synthesis

Answer 1

no

Question 2

does eating sugar stimulate fat synthesis

Answer 2

yes

Question 3

what is the function of GLUT2

Answer 3

glucose, galactose and fructose out of intestine and into blood, into the liver, insulin independent

Question 4

what is the function of GLUT4

Answer 4

glucose into muscle and adipose tissue, stimulated by insulin, stimulated by low energy charge, facilitated diffusion

Question 5

how does glucose get into the muscle and adipose tissue

Answer 5

facilitated diffusion

Question 6

glucose will more from the blood to the muscle as long as the concentration of glucose is _________ in muscle (and transporters are available)

Answer 6

lower

Question 7

when muscle glycogen is _____, G6P is converted into glycogen

Answer 7

low

Question 8

when muscle energy charge is _____, G6P runs through glycolysis, prep step, and krebs

Answer 8

low

Question 9

by adding a ____________ to glucose, the glucose concentration in muscle remains low and glucose keeps coming in

Answer 9

phosphate

Question 10

_________ or _____________ result in a tenfold increase in glucose uptake in skeletal muscle

Answer 10

exercise or insulin

Question 11

about 90% of insulin-stimulated glucose uptake occurs where

Answer 11

skeletal muscle

Question 12

_______ stimulates the accumulation of GLUT4 in the cell membrane for 1-2 hours after

Answer 12

exercise

Question 13

exercise ________ the number of GLUT4 proteins in skeletal muscle

Answer 13

increases

Question 14

three important things about glucokinase

Answer 14

lesser affinity for glucose, not inhibited by its product, stimulated by insulin

Question 15

what is the chain reaction when you eat carbohydrate

Answer 15

eat carb, elevated blood glucose, elevated insulin, fat and muscle glucose transport, is muscle full (of glycogen?) if no then glucose is stored as glycogen. if yes then glucose goes to liver

Question 16

What are the three main enzymes of fat building

Answer 16

citrate lyase, acetyl CoA carboxylase and fatty acid synthase (CAF, a fat cow)

Question 17

fatty acid synthesis occurs where

Answer 17

cytosol, mostly in the liver

Question 18

What is inhibited in the krebs cycle and what does it kick out

Answer 18

isocitrate DH. kicks out citrate

Question 19

citrate–>acetyl CoA

Answer 19

citrate lyase

Question 20

Acetyl CoA–>Malonyl CoA

Answer 20

Acetyl CoA carboxylase

Question 21

once malonyl CoA is created where does it go

Answer 21

fatty acid synthase (FAS). FAS adds the malonyl CoA’s to a growing fatty acid

Question 22

what stimulates Acetyl CoA Carboxylase

Answer 22

citrate and insulin

Question 23

what inhibits Acetyl CoA Carboxylase

Answer 23

malonyl CoA, Palmitoyl CoA, epinephrine

Question 24

what diets increase the synthesis of Acetyl CoA carboxylase

Answer 24

high carbohydrate, low fat

Question 25

what diets decrease the synthesis of Acetyl CoA carboxylase

Answer 25

high fat, fasting

Question 26

Acetyl ACP + Malonyl ACP –>

Answer 26

Acetoacetyl-ACP

Question 27

explain the CRDR of fatty acid synthase

Answer 27

Condenses (adds malonyl CoA), Reduces (with NADPH), Dehydrates, Reduces (with NADPH)

Question 28

tell the story of fat synthesis

Answer 28

eating lots of sugar, not fat, stimulates fat synthesis. Eating sugar or resting raises blood glucose and energy charge. Muscle glycogen is full. Hexokinase (muscle) is inhibited by G6P. Liver glucokinase is stimulated by lots of glucose and NOT inhibited by G6P so the liver will run glycolysis. Lots of ATP and acetyl CoA is created. ATP inhibits Isocitrate DH and stops krebs. Citrate spills out and its acetyl CoA is given back by citrate lyase. Acetyl CoA is turned into malonyl CoA by acetyl CoA carboxylase. Fatty acid synthase (FAS) keeps adding malonyl CoA’s to a growing fatty acid (CRDR). Palmitate (16:0) is eventually created. WHEW!

Question 29

______ is the primary site of fructose disposal

Answer 29

Liver

Question 30

conditions that stimulate fat synthesis

Answer 30

high energy charge, lots of acetyl CoA, lots of NADH and FADH2, lots of citrate, lots of sugar, insulin

Question 31

key enzymes of fat synthesis

Answer 31

Citrate lyase, Acetyl CoA carboxylase, Fatty acid synthase (CRDR)–> CAF