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