BC 26 Glycolysis

Question 1

priorities of liver in fed state

Answer 1

1. glycolysis/etc/op/tca
   - for the liver immediate energy
2. glycogenesis
   - to clear portal glucose for short term fasting
   - also in muscle (but selfish)
   - liver glycogen later used for export to blood
3. FA synthesis/TAG synthesis: lipogenesis
   - shunting acetyl CoA to Fatty acyl coA (FA) and compining it with flycerol P to form TAG

1 and 2 first, as these needs are met, then shut to 3

Question 3

glucose transporters

Answer 3

passive

G1: 1km
G2: 15-20
G3: <1
G4: 2.5-5 (insulin dependent) (muscle/adipo)

Question 4

Glycolysis conditions and products

Answer 4

aerobic: 1 G + 2 ATP +2 ADP + 2 NAD -> 2 Py + 4ATP + 2 NADH
-10 steps
-pyruvate for mitochondria
in O2 cells with mito

anaerobic: 1 G + 2ATP + 2 ADP + 2NAD + 2NADH -> 2 lactate + 4ATP
- 11 steps
- lactate for leaving cell
- cells with no mito for rapid ATP (early muscle ex)

Question 5

Glucokinase/Hexokinase

Answer 5

both phosphorylate glucose as a sugar trap
-transcriptionally regulated and others

Hexokinase: most tissues

• low Km and low Vmax (max at fasting state)
• offers slow and steady trapping
• INHIBITED by G6P

GLucokinase: liver and Panc B cells

• high Km and High Vmax
• allows liver to trap massive amounts of dietary glucose entering from portal blood
• prevents large amounts of glucose from entering systemic circulation
• minimizes postprandial peripheral hyperglycemia