Wk1 Glucose Metabolism Flashcards Preview

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Flashcards in Wk1 Glucose Metabolism Deck (18):
1

Duration of ingested glucose oxidation for fuel after a meal:

~ 4 hrs -- decreases rapidly then switches to glycogenolysis in liver

slides 4-5

2

Four main processes stimulated by insulin:

1. glycogen synthesis

2. FA synthesis

3. TG synthesis

4. Liver glycolysis

3

3 main processes stimulated by glucagon:

1. glycogenolysis

2. gluconeogenesis

3. lipolysis

4

Four substances that oppose insulin:

1. Glucagon

2. catecholamines

3. cortisol

4. Growth hormone

**all stimulate liver to produce glucose

5

Pathway for insulin release from pancreatic beta cells:

glucose --> GLUT 2 into cell --> TCA cycle --> ATP --> inhibits K+ channel --> depolarizes cell --> increased intracellular Ca++ --> Ca mediated fusion of insulin containing vesicles with plasma membrane

**slide 10

6

Deficiency in glucokinase in pancreatic beta cells:

MODY2

maturity onset diabetes of the young type 2

7

Insulin receptor type in tissue cells:

tyrosine kinase --> PI-3,4,5-trisP --> PDK 1 phosphorylates PK B --> active PK B phosphorylates intracellular targets to modulate metabolism

8

PK B effect on glycogen synthase:

activation via inhibition of glycogen synthase kinase-3

and

activation of protein phosphatase-1

9

Two key gluconeogenic enzymes:

What transcrition factor regulates them?

G-6-P

PEP-CK

FOX01

10

PKB (Akt) effect on FOX01:

inhibits expression by phosphorylating it

**so insulin inhibits gluconeogenesis
-which makes sense because there is glucose available in the blood already

11

glucagon pathway to gluconeogenesis in fasted stated:

GPCR -->cAMP --> PKA --> CREB --> PGC1a --> PEPCK and G6P

12

Recap of insulin vs glucagon on ....

slide 18

13

Fruc 2,6 BP and Fruc 6-P

Which inhibits and which activates PFK?

F2,6 -- activates (glucose abundant)

F6P -- inhibits (glucose scarce)

14

glucagon effect on Fruc 2,6 BP:

inhibits --> inhibiting glycolysis and promoting gluconeogenesis

15

Other than decreased glucose uptake, what two thing happen with insulin deficiency?

glucagon in excess with lack inhibition by insulin causing:

1. increased protein catabolism --> increased gluconeogenisis --> even higher blood sugar

2. increased lipolysis --> increased ketogenesis --> can lead to ketoacidosis

16

DM1 vs DM2?

DM1: increased TAG, ketone bodies, FAs, Glucose

DM2: increased TAG and Glucose only

**slide 25

17

Metformin MOA:

activates LKB1

LKB1 phosphorylates (activates) AMPK

AMPK phosphorylates TORC2 (preventing it from transcribing gluconeogenic genes in nucleus)

18

Good luck

this shit is hard