Citric acid cycle and Cori cycle Flashcards
Where does the CAC take place and why?
Does it need oxygen to take place?
Mitochondrial matrix
Because that’s where the enzymes are
Needs oxygen
Main inputs and outputs of the CAC?
INPUT: acetyl CoA
OUTPUTS: 3NADH and FADH2 (reduced)
Oxaloacetate is the final product in step 8 which starts to cycle again
What substances regulate the CAC?
ATP and NADH
> high levels of ATP inhibit & low levels of ATP speed up Step 1 of the CAC
> high levels of ADP and NADH speed up and low levels of ADP and NADH inhibit Step 3 of the CAC
What is the Cori Cycle?
Where lactate is converted into pyruvate via gluconeogenesis (non carb source converted to glucose)
(important because of lactate formation during exercise)
Why are B vitamins important? What do they function as?
They function as coenzymes in carbohydrate metabolism
How many steps are there in the CAC and how many of these involve redox reactions?
8 steps, 4 redox
steps 3, 4, 6 8 are reduction reactions
Where does the input for the CAC come from?
> the breakdown of carbohydrate (glycolysis), lipid (beta
oxidation) or protein (transamination)
> after pyruvate has been produced in glycolysis (from glucose) it is
converted to Acetyl CoA when oxygen is present
What is the final output of CAC used for?
The electron-rich coenzymes produced in the CAC (1 FADH2 and 3 NADH) are taken to the electron transport chain, where they off-load their electrons to begin the electron transport chain (ETC)
Where in the body can glycogen be stored and for what purpose?
> liver and muscle
> it can be broken down into glucose to produce energy or
increase the blood glucose level in the fasting state
What is the purpose of breaking down stored glycogen and what is the process called?
> Glycogen breakdown occurs via glycogenolysis
> increases the blood glucose level so glucose can be taken to glucose-dependent organs such as the brain
