Integration of Metabolism

Question 1

what are the 3 main decisions in the reductionist approach ?

Answer 1

what to do with the following:

1. G6P
2. pyruvate
3. acetyl coa

Question 2

G6P uses

Answer 2

convert to:

1. G1P to create glycogen
2. thru PPP to create R5P
3. F6P to create pyruvate

Question 3

what can pyruvate be converted into?

Answer 3

acetyl coa
alanine
lactate
OAA

Question 4

fates of acetyl CoA

Answer 4

1. enter ketone body synthesis
2. FA synthesis
3. TCA or OxPhos cycle

Question 5

brain

Answer 5

no fuel reserve

wants glucose
—use ketones in starvation

does not export fuel

Question 6

skeletal muscle during rest

Answer 6

glycogen, protein reserves

wants fatty acids

does not export fuel

Question 7

skeletal muscle during activity

Answer 7

no reserves

uses glucose

exports lactate

Question 8

heart muscle

Answer 8

no reserves

wants fatty acids

does not export

Question 9

adipose tissue

Answer 9

TAG reserves

wants to use fatty acids

exports fatty acids and glycerol

Question 10

liver

Answer 10

reserves = glycogen, TAGs

uses glucose, FAs, AAs

exports: FAs, glucose, ketone bodies

Question 11

what are the main fuel producers of the body

Answer 11

liver - glucose
adipose - FAs
kidneys - glucose during starvation only

Question 12

what are the main fuel consumers of the body

Answer 12

skeletal muscle
glycogen —> creatine Pi —> lactate

brain
glucose —> ketones

heart
FAs —> lactate/ketones

Question 13

significance of liver lacking CoA transferase

Answer 13

it can produce but not use ketone bodies

Question 14

organs containing the urea cycle

Answer 14

liver

kidneys

Question 15

LDL

Answer 15

origin - vldl

destination - all cells

role – cholesterol distribution

Question 16

HDL

Answer 16

origin - empty liver
destination - full liver

role - cholesterol collection

Question 17

VLDL

Answer 17

origin - liver
destination - adipose

role - TAG transport

Question 18

chylomicron

Answer 18

origin - intestine
destination - adipose

role - TAG transport

Question 19

diabetes mimics _____ conditions

Answer 19

starvation conditions

the insulin deficiency blocks entry of glucose into muscle and adipose cells

problems w/ the insulin receptor - its never put out on memb of cells
or
insulin is never produced

Question 20

enzyme regulators of metabolism

Answer 20

AMPK and mTOR
serine/threonine kinases w/ opposite functions

mTOR increases synthesis pathways - on in fed state
AMPK inhibits it

Question 21

enzyme metabolism regulators - sirtuins

Answer 21

deacetylate lysine

use NAD+
redox rxn
activated when [NAD+] is high

Question 22

metabolism regulators - hormones

Answer 22

insulin
glucagon
epinephrine
leptin
ghrelin
PYY3-36
adiponectin

Question 23

insulin

Answer 23

released from pancreas

acts in fed state
tells cells to uptake glucose

Question 24

leptin

Answer 24

released from adipose

acts in full state
meant to tell you you’re full

Question 25

CCK and GLP1 plus leptin

Answer 25

all act in full state to tell you to stop eating

but leptin in long lasting
others are short

Question 26

hungry signals

Answer 26

ghrelin
adiponectin
PYY3-36

Question 27

cortisol

Answer 27

slow acting
periods of chronic stress
a cholesterol derivative
tissue specific actions:
adipose --- release FAs
skeletal --- protein catabolism
liver --- increase gluconeogenesis