Carbs Flashcards
(31 cards)
What is a disaccharide?
two monosachirides linked by an alpha glycosidic bond
What is the normal plasma glucose level of a human?
4-5 mm, ruminant is around 3-4 mm
What are the hypoglycemia and the hyperglycemia levels ?
hypo = half normal levels hyper = extended elevation above 10 mm
What are the inhibitors of PFK1?
ATP, Citrate, H+
What are the stimulators of PFK1?
Fructose 2,6- bisphosphate, AMP
What are the inhibitors of pyruvate kinase?
ATP and alanine (allosteric), glucagon (covalent)
What are the stimulators of pyruvate kinase?
allosteric- fructose-1,6-bisphosphate
What are the inhibitors of pyruvate dehydrogenase?
NADH + acetyl CoA + ATP
What are the stimulators of pyruvate dehydrogenase?
Mg+, Ca+, Insulin
What is the function of the respiratory chain?
series of catalysts that collects and transports reducing equivalents (NADH and FADH2) directing them to final reaction with O2 to produce water
- catalysts are located on the inner mitochondrial membrane
What is the yield of NADH via the respiratory chain?
2.5 ATP
What is the yield of FADH2 via the respiratory chain?
1.5 ATP
What is the total ATP generated from the TCA cycle?
10 ATP
Name the two different types of shuttles, which one is more efficient?
Malate/asparate
glycerophosphate
malate/aspartate is more efficient (uses NADH rather than FADH2, which only generates 1.5 ATP)
What is the name of the inhibitor of glucose- 6 phosphatase?
NADPH
Name the four enzymes of the gluconeogenic quartet and state their function:
pyruvate carboxylase- in the mitochondria
phosphenolpyruvate carboxykinase- mitochondria and in the cytosol
fructose-1,6-bisphosphatase- cytosol
glucose-6-phosphatase- smooth ER
Where does propionate come from?
comes from carbohydrate digestion within ruminants
What is the stimulator for pyruvate carboxylase?
acetyl CoA is the stimulator
What is the stimulator for phosphoenolpyruvate carboxykinase?
induced by glucocorticoids
What is the stimulator for fructose-1,6-bisphosphatase?
F-2-6-bisphosphatase
Where are glucagon receptors located?
liver and adipose tissue cells but not muscle cells
Where is gluconeogenesis located?
liver (and in the kidney to a lesser extent)
What is the effect on glycogon on fructose-2,6-bisphosphatas and pyruvate kinase?
inhibits pyruvate kinase
stimulates F-2,6-bisph
What is the structure of glycogen?
polysaccharide of a-D-glucose linked a1-4 and branches a1-6
