Acetyl-Coa and the CAC Flashcards
Acetyl CoA can be formed from
carbohydrates, fatty acids, and amino acids
Once formed acetyl CoA can serve as
substrate for CAC, metabolic precursor for formation of fatty acids, ketone bodies, and cholesterol
Coenzymes of the PDH complex
2 solube: NAD+ and CoA
3 tightly bound: FAD, lipamide, TPP
vitamins of PDH complex
Thiamine (b1) - TPP
Riboflavin (b2) - FAD
Niacin (b3) - NAD+/NADH
Pantothenic acid (b5) - CoASH
Where does PDH complex take place
mitochondrial matrix
Pyruvate decarboxylase/dehydrogenase
removes CO2 and bind it to TPP
Dihydrolipoyl transacetylase
oxidizes hydroxyethyl intermediate to an acetyl group and transfers to lipoic acid that’s bound to enzyme, then acetyl group is transferred to CoASH
dihydrolipoyl dehydrogenase
reduces sulfuers of lipoic acid re=oxidized, depend on FAD
When is PDH less active
phosphorylated state
When is PDH more active
de-phosphorylated state
What inhibits PDH complex
Acetyl-CoA and NADH
What stimulates the PDH complex
CoASH, pyruvate, NAD+
Roles of CAC
major ATP-generating pathway. Source of metabolic precursors for biosynthesis
Where does the CAC take place
mitochondrial matrix
What is the fuel of the CAC
acetyl-CoA