Carbohydrate Metabolism-Gluconeogenesis Flashcards
How many grams of glucose does the body need in a day?
160 g of glucose per day
When does gluconeogenesis occur?
When all your glycogen supplies are out and readily available glucose is gone (about a few hours)
Where does gluconeogenesis readily occur?
Liver, kidney, small intestine
What are the major precursors to gluconeogenesis?
AAs, lactate (Cori Cycle), Glycerol backbone
What are the controlling steps of gluconeogenesis?
Pyruvate Carboxylase
PEP Carboxykinase
F-1,6-Bisphosphatase***
G-6-Phosphatase
What are the by-product regulators of gluconeogenesis?***
(+) glucagon, cortisol, acetyl CoA, citrate, THYROXINE
-) f-2,6-bp (adp,amp….WTF????????
What is the role of pyruvate carboxylase?
First step in gluconeogenesis:
-mitochondrial enzyme that catalyzes the reactionfrom
pyruvate–> OAA.
-requires CO2, ATP, biotin
Why is pyruvate converted to OAA in the mitochondrial matrix?
Phosphoenyl Pyruvate is more easier to form from Oxaloacetate than it is from pyruvate.
What is the role of Malate Dehydrogenase Complex in Gluconeogenesis?
Malate dehydrogenase complex is used to create malate from oxaloacetate so that the 4-C molecule can be moved through the mitochondria.
Then the malate can be converted back to OAA by cytosolic MALATE DEHYDROGENASE
What are the regulatory steps of gluconeogenesis?
PEP carboxykinase
F-1,6-Bisphosphatase**
Glucose-6-phosphatase
Where is the final step of gluconeogenesis occuring (ex: glucose-6-phosphatase activity)?
lumen of the ER
What is the link between gluconeogenesis and the Cori Cycle?
Lactate produced from anaerobic respiration via muscle cells will come through the blood to the liver (kidney, small intestine-secondarily) to feed into gluconeogenesis production to be given back in the bloodstream for the muscle cells to consume.
What is the effect of F-1,6-BP deficiency?
The F-1,6-BP deficiency will cause:
-hypoglycemia, lactic acidosis, ketosis, hyperventilation (to remove the h+ ions and become basic)
h20+co2–> h2c03–> h+ + hc03-
What is Van Gierke Disease?
Van Gierke Disease is a disease that occurs via the Glucose 6 phosphatase enzymatic problem:
SX: lactic acidosis, hypoglycemia, ketosis, hepatomegaly (high G6P–> GLYCOGENOSIS)
