Q 5: CHO Metabolism: Glycolysis, the Citric Acid Cycle, and Oxidative Phosphorylation Flashcards
What is the primary electron carrier?
NAD+
What is the electron acceptor in glycolysis?
NAD+
Is glycolysis anaerobic or aerobic?
anaerobic
What are the two stages of glycolysis?
preparatory - phosphorylation
payoff - oxidation reduction
What cell types in the body receive their primary source of energy through glycolysis?
erythrocytes (lack mitochondria)
cancer cells
anaerobic bacteria
What two pathways use ~80% of the same enzymes?
glycolysis and gluconeogenesis
What type of rxn does hexokinase initiate on glucose in glycolysis?
transfer rxn (moves phosphate from ATP to glucose)
What is the difference between di and bi phosphate?
Di-means there are two phosphates connected at one location
Bi-means there are two phosphates connected at different locations
Why is the first ATP of glycolysis important?
it keeps glucose in the cell
Where in the cell does glycolysis occur?
in the cytoplasm
What do you yield from the payoff phase in glycolysis?
2 pyruvate
2 ATP
2 NADH + H+
What inhibits glycolysis?
high amounts of citrate (pyruvate –> citrate)
high amounts of ATP
What is the rate limiting enzyme of glycolysis
phospho-fructokinase 1
What is the rate limiting step of the pentose phosphate pathway?
glucose 6-phosphate –> 6-phosphogluconate
What are the other names for the pentose phosphate pathway?
phosphogluconate pathway
hexose monophosphate shunt
What key cells are synthesized in the pentose phosphate pathway?
NADPH
Ribose sugars
- nucleotides
- ATP
- FAD
- Coenzyme A
What inhibits the pentose phosphate pathway?
NADPH (which is produced in the pathway)
Why is NADPH necessary/what is it used for?
creating FA’s (reductive biosynthesis)
free radical protection
it must be maintained within the cell
Why is fermentation important/why do we need it?
we need electron acceptors (it produces 2NAD+)
if you don’t have electron acceptors, glycolysis doesn’t happen
What is the substrate for liver gluconeogenesis?
lactate
What is the electron acceptor of the NADH produced in glycolysis?
lactate
What happens to lactate after its production?
It is shuttled into the blood, taken up by the liver and converted into glucose with ATP within the liver
What rxns occur in the mitochondria?
citric acid cycle (starting with pyruvate –> acetyl CoA –> citric acid cylce)
What organelle has a unique genome inherited through the mother?
mitochondria (which is found in the egg)
What organelle is involved in apoptosis?
mitochondria
What spills out of the mitochondria when it is undergoing apoptosis?
cytochrome C
What does cytochrome C from the mitochondria bind to, after spilling out of the mitochondria, in apoptosis?
ATP, which will induce Apaf-1 to form an apoptosome which eventually leads to cell death/resorption
What enzyme converts pyruvate to acetyl-CoA?
pyruvate dehydrogenase complex