Cori and Krebs Flashcards
Give a summary of glycolysis. So name each enzyme used for the 10 steps
1) Hexokinase HexoK
2) Phospho Isomerase
3) PFK1
4) Aldolase
5) TPI
6) GAPDH
7) PGK
8) PGM
9) Enolase
10) PK
What are the 5 major fates of Pyruvate?
1) Ethanol
2) Lactate
3) Acetyl CoA
4) Oxalacetate
5) Alalanine
What are the 2 fates of pyruvate made in the mitochondrial matrix?
Oxaloacetate and Acetyl CoA
What process gives ethanol from pyruvate?
Fermentation
Name the following things for fermentation of pyruvate
1) how many steps?
2) describe each step
3) enzymes used for each step
4) the extras needed for each step
5) any byproducts?
6) reversible or irreversible?
1) 2 step process
2) first step is pyruvate to acetaldehyde
2nd step is acetaldehyde to ethanol
3) pyruvate decaroxylase for first step
alcohol dehydrogenase for second step
4) TPP and Mg2+ for first step
NADH + H+ for second step
5) CO2 first step. NAD+ formed for 2nd step
6) both reversible
How is lactate formed?
1) Name the enzyme used
2) Name the conditions needed
3) what important role does the enzyme play?
4) high amounts of what can produce what?
L- Lactate is formed from pyruvate during anaerobic glycolysis
1) Lactate dehydrogenase
2) Anaerobic
3) Regenerates NAD+ for step 6 of glycolysis
4) High amounts of lactic acid can produce acidosis
what is the cori cycle?
metabolic pathway in which lactate produced from pyruvate in the muscles is transferred to the liver where it is then converted to glucose. This glucose is then transferred back to the muslces and stored as glycogen and the cycle is repeated
What role does ATP play in the muscle and in the liver during the cori cycle.
In the muscle, the production of atp when glycogen is converted to lactate is used for rapid contraction of the muscle.
In the liver, ATP is used in the synthesis of Glycogen from lactate during recovery. (GNG)
Descirbe the structure of gylcogen and describe the bonds and branching
Polysaccharide
alpha-D-glucose units linked via alpha1 ->4 glycosidic bonds with alpha1->6 branch points
Glycogen is the storage form of what in the body?
Storage form of carbohydrate in the body
Why is glycogen critical during fasting?
Liver glycogen provides a source of blood glucose
What type of glycogen cannot give rise to blood glucose?
Muscle glycogen
Glycogenolysis is what?
Breakdown of glycogen and involves
1) Glycogen phosphorylase
2) Debranching enzyme
3) Phoshoglucomutase
Glycogensis is what?
Synthesis of glycogen and involves
1) UDP glucose pyrophosphorylase
2) Glycogen synthase
3) Amylo 1->4 to 1->6 transglycosylase (glycogen branching enzyme)
Describe how glycogen phosphorylase works and what it needs
It needs an inorganic phosphate.
It works by shortening the glycogen by one residue and adding phosphate onto that residue.
So produces glucose1phosphate and the rest of the glucose residue
