Cellular Respiration Flashcards
Organisms store glucose as…
Glycogen or starch.
In cells, glucose is oxidized by…
A long series of redox reactions. The released free energy is used to synthesize ATP. Known as cellular respiration.
4 processes of cellular respiration
Glycolysis, pyruvate processing, citric acid cycle, and electron transport/oxidative phosphorylation.
Glycolysis
Sequence of enzyme catalyzed reaction by which glucose is converted into pyruvate.
What are the 4 enzymes in the 4 steps of the glycolysis prep phase?
Hexokinase, phosphohexose isomerase, phosphofructokinase-1, and aldolase.
What is produced at the end of the prep phase in glycolysis?
Glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, and 2 ADP.
What are the 6 enzymes in the 6 steps of the glycolysis payoff phase?
Triose phosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate kinase, phosphoglycerate mutase, enolase, and pyruvate kinase.
What is produced at the end of glycolysis?
2 pyruvate, 2 NADH, 2 H, 2 H2O and 2 ATP.
Tautomerization
Effectively lowers the concentration of the reaction product, drives reaction towards ATP formation.
How is glycolysis regulated?
Feedback inhibition. High levels of ATP inhibit the third enzyme, phosphofructokinase.
What happens to phosphofructokinase when there is too much ATP?
Phosphofructokinase has two binding sites for ATP; when ATP binds the the active site the reaction continues, when ATP levels are too high, it will bind the regulatory site and inhibits the enzyme
Substrate-level phosphorylation
Occurs when ATP is produced by the enzyme-catalyzed transfer of a phosphate group from an intermediate substrate to ADP. How ATP is produced in glycolysis and the citric acid cycle.
What is used in glycolysis (consumed)?
1 glucose, 2 ATP, 2 NAD+
What is produced in glycolysis?
2 pyruvate, 4 ATP, 2 NADH
Net amount of ATP production at the end of glycolysis
2 ATP
Fates of pyruvate
Anaerobic conditions (fermentation) or aerobic conditions (citric acid cycle).
Cristae
Extensions of the inner mitochondrial membrane.
Mitochondrial matrix
Inside the inner mitochondrial membrane.
Where does pyruvate processing take place?
Enzyme complex called pyruvate dehydrogenase in mitochondrial matrix (eukaryotes).
What are the series of reactions that pyruvate undergoes?
One of its carbon’s is oxidized to CO2, NADH is produced, and the remaining two carbon unit is attached to coenzyme A producing acetyl CoA.
What does thiamine deficiency result in
In sufficient pyruvate dehydrogenase activity.
What are the 8 enzymes of the citric acid cycle?
Citrate synthase, aconitase, isocitrate dehydrogenase, alpha ketongluatarate dehydrogenase, succinyl-coA sythetase, succinate dehyrdogenase, fumarase, malate dehydrogenase