Overview of Carbohydrate Metabolism Flashcards
True or false: there is a storage pool for protein in the body.
False
The body’s largest storage ability is for _____.
fat (followed by glucose in second place)
The average 70 kg person has ________ kcal in fat storage.
120,000
True or false: muscle glycogen cannot be released as free glucose.
True –only liver glycogen can do this.
Liver glycogen stores in an average 70 kg man is _______.
400 kcal
“Reduced” molecules are ________, while “oxidized” molecules are _________.
nutrients; products
The hormone of the fed state is _____________, while the hormone of the fasted state is ___________.
insulin; glucagon, cortisol, catecholamines, and GH
The overall effect of de novo lipogenesis is ___________.
turning acetyl co-a into fatty acids (hence why eating too much carbohydrate makes you gain weight)
Beta-oxidation turns ____________.
fatty acids into acetyl co-a
The rate-limiting step in glycolysis is ___________.
the addition of a phosphate group –by phosphofructokinase –to form fructose 1,6-bisphosphate
What three things are produced by the TCA cycle?
NADH, FADH2, and GTP
What three molecules are commonly broken down to create substrates for gluconeogenesis?
Glucose, which forms lactate by glycolysis
Proteins, which form amino acids from proteolysis
Triglycerides, which form glycerol from fat oxidation
What three enzymes and steps are regulated in the gluconeogenesis pathway?
Pyruvate to phosphoenolpyruvate (by pyruvate carboxylase and then phosphoenolpyruvate carboxykinase)
Fructose 1,6-bisphosphate to fructose 6-phosphate (by fructose 1,6-bisphosphatase)
Glucose 6-phosphate to glucose (by glucose 6-phosphatase)
What are the four reactions in glycogen synthesis from free glucose?
Glucose to glucose 6-phosphate
Glucose 6-phosphate to glucose 1-phosphate
Glucose 1-phosphate to UDP-glucose
UDP-glucose to glycogen (by glycogen synthase) regulated step
What is the priority order (based on glucose abundance) that dictates which pathway glucose metabolism will take?
Low glucose levels: glycolysis
Intermediate glucose levels: glycogen synthesis
Abundant glucose levels: pentose phosphate pathway
