pyruvate pathways, gluconeogenesis, glycognesis, glycogenolysis

pentose phosphate pathway

converts glucose to ribose, generates NADH

aerobic pyruvate pathway

pyruvate decarboxylated w/ pyruvate dehydrogenase to form acetyl CoA + CO2

anaerobic pyruvate pathway

pyruvate to lactate using oxidation/reduction w/ dehydrogenase and NADH+ + H+; cori cycle

anaerobic

pyruvate decarboxylated to acetaldehyde and then reduced to ethanol; regenerates NAD+ to continue glycolysis; fermentation

gluconeogenesis

synthesis of glucose from non-carb sources that takes place in the liver

when is gluconeogenesis used

to replenish depleted liver glycogen, convert lactate to glucose, maintain blood glucose levels when glycogen depletes

gluconeogenesis step 1

pyruvate carboxylated unto oxaloacetate using ATP hydrolysis

gluconeogenesis step 2

oxaloacetate phosphorylated phosphoenolpyruvate using phosphoenolpyruvate carboxykinase

gluconeogenesis step 3

fructose-1-6-biphosphate cleaves a phosphate by hydrolysis to make fructose-6-phosphate

gluconeogenesis step 5

same as step 7 of glycolysis, but ATP required

glycogenesis

glycogen synthesized from glucose-6-phosphate

glycogenesis step 1

glucose to glucose-6-phosphate using ATP/hexokinase and then isomerized to glucose-1-phosphate

glycogenesis step 2

UTP activated glucose-1-phosphate to form UDP-glucose and pyrophosphate (PPi) using UDP-glucose pyrophosphorylate

glycogenesis step 3

glucose unit of UDP-glucose attaches to the end of a glycogen chain by using glycogen synthase

glycogenolysis

2 step pathway where glucose-6-phosphate is produced from glycogen and does not require UTP or UDP

glycogenolysis pathway

glycogen ——>(glycogen phosphorylase) glucose-1-phosphate ——> (phosphoglucomutase) glucose-6-phosphate

priority of energy source

carbohydrates/polysaccharides —→ glycogen ——> triaclyglycerols ——> proteins