Respiration Flashcards
(15 cards)
What is glycolysis?
Takes place in the cytoplasm
Breakdown of glucose into pyruvate molecules
Doesn’t require oxygen
Per glucose -
2 ATP
2 reduced NAD
2 pyruvate
Explain the glycolysis of glucose?
Glucose is phosphorylated using 2 ATP molecules to form hexose bisphosphate
Hexose bisphosphate is split into 2 TP molecules
A hydrogen is removed from each TP molecule by NAD to form reduced NAD
2 pyruvate molecules formed
4 molecules of ATP produced
What are the reactants and products of glycolysis?
Reactants:
1 glucose
2 ATP molecules
Products:
4 ATP
2 NADH
2 pyruvate
What is the Link reaction?
Takes place in mitochondrial matrix
connects glycolysis and Krebs cycle
Explain the Link reaction
Pyruvate is decarboxylated - loses 1 CO2 molecule
Hydrogen is removed from pyruvate to form 2C acetate
NAD is reduced to NADH
Acetate binds to coenzyme A to form acetyl CoA
Reactants and products of the link reaction
Reactants:
Pyruvate
NAD
Coenzyme A
Products:
Acetyl CoA
Reduced NAD
CO2
What is the krebs cycle?
After the link reaction
Takes place in the mitochondrial matrix
uses acetyl CoA
Explain the Krebs Cycle
Acetyl CoA binds with oxaloacetate to form 6C molecule, citrate
Citrate is decarboxylated and dehydrogenated to form 5C molecule
Releases CO2 and Hydrogen
NAD is reduced to NADH
5C molecules is decarboxylated and dehydrogenated
4C oxaloacetate is formed
ATP produced
3 hydrogens released
2 NAD are reduced to 2 NADH
FAD is reduced to FADH
What is oxidative phosphorylation?
Last stage of aerobic respiration
Generates ATP by chemiosmosis
takes place in inner mitochondrial membrane of cristae
Explain oxidative phosphorylation
NADH and FADH release H+ and e- into mitochondrial matrix
Electrons are passed onto an electron carrier
Electrons are passed along ETC, releasing energy as they move along the ETC
Energy is used to actively transport H+ into the intermembrane space
This forms a proton gradient
Protons diffuse back into mitochondrial matrix through ATP synthase which forms ATP from ADP and Pi
Oxygen acts as final electron acceptor and combines with electrons and protons to form water
What is the total ATP production aerobic respiration?
Glycolysis: 2 ATP
Link reaction: 0
Krebs cycle: 2
Oxidative phosphorylation: about 30
Total: 34
Explain alcohol fermentation during anaerobic respiration?
Pyruvate loses molecule of CO2 and is converted to ethanal
Ethanal accepts hydrogen from NADH to produce ethanol
NAD is regenerated
Ethanol is a waste product
Explain lactic acid fermentation during anaerobic respiration?
Pyruvate accepts a hydrogen from NADH
Catalysed by lactate dehydrogenase
Lactic acid forms and NAD is regenerated
Lactic acid can be oxidised to pyruvate to generate more ATP or stored as glycogen
How does respiratory substrate affect respiration?
cells can respire with carbs, proteins and lipids
Lipids release most, then proteins, then carbohydrates
Majority of ATP produced in chemiosmosis
What is respiratory quotient?
Respiratory quotient = CO2 produced / oxygen consumed
If RQ is greater than 1 then there is shortage of oxygen since organism respiring aerobically and anaerobically
Carbs - 1
Protein - 0.9
Lipids - 0.7
