Biochemistry Flashcards
What are the products of glycolysis?
2 ATP, 2 NADH, 2 Pyruvate
What is the rate limiting enzyme in glycolysis?
Phosphofructokinase-1
Where in a cell does glycolysis take place?
Cytoplasm
Where in a cell does the Krebs cycle take place?
Mitochondrial matrix
Name 4 ways in which ATP can be produced?
- Krebs cycle.
- Glycolysis.
- Oxidative phosphorylation.
- Substrate level phosphorylation.
What enzyme of glycolysis is inhibited in acidosis?
Phosphofructosekinase-1 (PFK-1 is pH dependent).
What enzyme catalyses the formation of 3-phosphoglycerate from 1,3-bisphosphoglycerate?
Phosphoglyceratekinase.
What enzyme catalyses the formation of glyceraldehyde-3-phosphate from dihydroxyacetone phosphate?
Triose phosphate isomerase.
Oxidative phosphorylation: What enzyme transports protons into the mitochondrial matrix?
ATP synthase
Is the mitochondrial membrane permeable or impermeable to ions?
Impermeable
What are steroid hormones synthesised from?
Cholesterol
Name 2 electron accepting coenzymes.
- NAD
- FAD
Approximately how many ATP molecules are produced from oxidation of NADH?
2.5
Approximately how many ATP molecules are produced from oxidation of FADH2?
1.5
Briefly describe what happens in anaerobic respiration.
NAD is regenerated from NADH. Pyruvate, from glycolysis, forms lactate. Lactate dehydrogenase catalyses this reaction. NAD goes back to glycolysis so ATP can be produced.
What enzymes regulate the Krebs cycle?
- Pyruvate dehydrogenase.
- Citrate synthase.
- Isocitrate dehydrogenase.
- α-ketoglutarate dehydrogenase.
Where does oxidative phosphorylation occur?
Mitrochondrial matrix
What is the final electron acceptor?
Oxygen
Describe the move of electrons in the electron transport chain?
Components of ETC accept electrons (reduced) and pass them along (oxidised)
What is normal blood glucose?
4.5 - 5.5 mmol/L
How is blood glucose maintained?
Through the action of anabolic and catabolic hormones.
What is the fate of pyruvate in anaerobic conditions?
Lactate formation catalysed by lactate dehydrogenase
RegenerationonNAD+
What regulates PFK?
ATP (inhibitor)
AMP (activator)
Citrate (inhibitor)
Fructose 2, 6 biphosphate (activator)
