TCA Flashcards
Other names for TCA cycle
Kreb’s
Citric Acid Cycle
This is the final pathway where the catabolism of ____, ______, and ______ converge and their ______ ____ being converted to CO2.
carbohydrates, amino acids, fatty acids
carbon skeletons
How does the TCA cycle intersect with other areas of Metabolism?
Catabolic pathways: the breakdown of some amino acids provides certain TCA cycle intermediates
Anabolic Poathways: some TCA cycle intermediates feed into biosynthetic pathways, such as the synthesis of certain amino acids
The terminal oxidation of all biomolecules providesmost of the energy carried by _____ and _____ for the subsequent production of ATP in the ETC.
NADH and FADH2
The ETC couples the oxidation of the reduced carriers produced within the TCA cycle with the production of ATP by ______ _______
oxidative phosphorylation
The TCA cycle is located in the ______, in close proximity to the ETC.
mitochondrial matrix
Describe a Linear Pathway
Starts with 1 metabolite and ends up with a different one (Glycolysis)
Describe a Cycle
Starts with a certain metabolite that undergoes multiple steps forming different intermediates but in the end the same initial metabolite is regenerated. There is no net loss or gain of intermediates.
What occurs in the Oxidative Decarboxylation of Pyruvate, the reaction required prior to the TCA cycle.
- Pyruvate transported into Mitochondria
- Converted into acetyl CoA by Pyruvate Dehydrogenase Complex (PDH)
- 1 C atom is released as CO2 and NADH is produced
Describe the structure of the PDH complex?
Protein aggregate of 3 separate enzymes (E1, E2, E3) that requires 5 coenzymes (TPP, Lipoamide, CoA, FAD, NAD+)
What make up the 5 coenzymes required by PDH?
Thiamine pyrophosphate, TPP: (thiamine, vit B1)
Lipoamide (can be synthesized in human cells)
CoA (pantothenic acid, vit B5)
FAD (riboflavin, B2)
NAD+ (nicotinamide, vitamin B3/niacin)
Name the activators of PDH
Pyruvate NAD+ ADP Ca2+ CoA
Name the deactivators of PDH
Acetyl CoA
NADH
ATP
phosphorylation ______ PDH while dephosphorylation _______ PDH
deactivates; activates
PDH is subject to ________ and _________.
substrate activation and product inhibition
