Chapter 17 Review Flashcards
The citric acid cycle is named this because ____________ is the first product.
tricarboxylic acid (TCA; aka citrate
What are the “high energy electron carriers?”
NAD+ and FADH
_____ is the final electron acceptor of the electron transport chain
O2
________ is consumed in the first step of the citric acid cycle. It is ______ in the last step
Oxaloacetate ; regenerated
The citric acid cycle
- makes glycolysis products
- import and export of metabolites (carbohydrates, fatty acids, amino acids) from several other metabolic pathways
Glycolysis produces __________ which then goes on to the citric acid cycle.
pyruvate
1 round of the citric acid cycle produces
2 CO2, 3 NADH, 1 FADH2, 1 ATP/GTP
All of the citric acid cycle is carried out in the _______ of the cell.
mitochondria ; so reactants must be generated in or transported in, and products needed elsewhere must be transported out or they are consumed in the mitochondria
_______ conditions necessary for the re-oxidation of NADH in the mitochondria
Aerobic
Pyruvate is transported into the mitochondria by a ___________.
pyruvate-H+ symport
Acetyl-CoA is considered a high energy molecule due to its ____________ and its corresponding high free energy of ________
thioester bond ; hydrolysis
Acetyl- CoA is produced oxidative decarboxylation by a multienzyme complex: __________
pyruvate dehydrogenase
Pyruvate dehydrogenase is made of _________.
3 enzymes that are grouped noncovalently. They catalyze the sequential steps of the pathway, a five part reaction (pyruvate releases CO2 and the acetyl group that then gets linked to CoA)
Why is the fact that pyruvate dehydrogenase a multienzyme complex important?
decreases diffusion distance b/w substrate and next enzyme, minimizes opportunity for side reactions s/t channeling b/wenzymes swinging with lipoyllysyl arm, allows for coordinated control of pathway
8 enzymes of the CoA Cycle catalyze
- condensation
- isomerization
- oxidation-reduction
- phosphorylation
- hydration reactions
