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Flashcards in Carbs Deck (12):

What is the pentose phosphate pathway important for

The synthesis of fatty acids - generation of NADHP for reductive biosynthesis

Synthesis of nucleotides (RNA and DNA)
- formation of ribose 5-phosphate

Dehydrogenation of glucose - 6- phosphate is the commuted step


What is glycogen in the liver stores for?

Storage for blood glucose maintenance


What is glycogen in muscle stores for?

Storage for local energy production ( only used by muscle itself)


What is gluconeogenesis

The synthesis of glucose from a non card source


Glucose 6-phosphatase expression is stimulated by?

Adrenaline , glucocorticoids

BUT suppressed by insulin


Glucose 6 phosphatase is located where?

The enzyme is in the lumen of the ER
needs transporters for substrates and products to get in and out


Substrates for gluconeogensis ?

Lactate to pyruvate

Glycerol to dihydroxyacetone phosphate DHAP

Aminoacids in various locations in TCA cycle and pyruvate


Why can glucose not be produced from fatty acids by gluconeogenesis

Fattys acids oxidised to acetyl coA
2 CO2 produced
Lost the carbons therefore no contribution to glucose carbons


Stimulation of gluconeogenesis in the liver

Glucagon and adrenaline- decreases glucokinasr , increases G6pase and PEPCK activity

Effect is at level of gene expression


What tissues are dependent on glucose

Erythrocytes ( no mitochondria , therefore cannot oxidise fuels - only energy from glycolysis )

Brain - fatty acids cannot cross the blood brain barrier


What does exenatide and liraglutide do?

Mimic incretins (GLP1)
Not cleaved by DDP4
Improve insulin secretion


What does sidagliptin and vildagliptin do?

Inhibit DDP4
Increase endogenous incretin mediated increase in insulin secretion
Oral drugs