aerobic respiration Flashcards
what are the four stages of respiration?
- glycolysis
- link reaction
- krebs cycle
- electron transport chain
where does glycolysis occur?
in cytoplasm
what is the aim of glycolysis?
to produce 2 pyruvates
what are 4 stages of glycolysis?
energy investment
cleavage
oxidation
energy generation
what happens in energy investment? how much ATP is used?
glucose is primed with energy by phosphorylation into glucose phosphate (1 ATP)
- isomeration step: fructose phosphate - so further activation can occur
- phosphorylation: fructose biphosphate (1ATP)
what happens during cleavage?
fructose biphosphate splits into two: triose phosphates
what happens in oxidation? how much ATP is formed?
each of the TP are oxidised by NAD which removes hydrogen from molecule which in turn it accepts to become reduced NAD (1 ATP formed per molecule) and becomes GP
what does GP stand for?
phosphoglycerate
what happens in energy generation ? how much ATP is formed?
each of GP converted into pyruvate which releases 1 ATP per pyruvatye
what is the overall products of glycolysis?
- 2 pyruvate
- 2 NADH
- 2 ATP (4 is formed but 2 is used in first stage)
where does link reaction occur? and what condition is needed?
in matrix of mitochondria - presence of oxygen
what type of reaction is link reaction?
redox reaction - pyruvate oxidised/NAD is reduced
what is the aim of the link reaction?
to produce 2 acetyl coA
what happens in decarboxylation of the link reaction?
pyruvate decarboxylase removes carbon from each pyruvate to produce acetate and carbon combines with oxygen to form carbon dioxide which diffuses into blood and is carried to the lungs
what happens during oxidation in link reaction?
pyruvate is oxidised by NAD which becomes reduced per molecule so 2 NADh formed
what happens in final step of link reaction?
acetate combines with co enzyme A to form acetyl coA x 2
what are the overall products of the link reaction?
- 2 CO2
- 2NADH
- 2 Acetyl Co A
where does the krebs cycle occur?
in matrix of mitochondria
what is the aim of krebs cycle?
- to regenerate oxaloacetate to prevent accumulation
- to provide electrons for electron transfer chain
- breakdown macromolecules into smaller ones
- source of intermediate compounds to manufacture other important substances such as fatty acids, amino acids and chlorophyll
what does acetyl coA combine with in first step?
oxaloacetate to produce citrate
what term describes the removal of carbon?
decarboxylation
what happens in decarboxylation in krebs cycle?
- oxaloacetate converted to ketoglucaric acid releasing CO2 and reduces NAD
- ketoglucaric acid converted to socrinic acid releasing CO2 and reduces NAD
what happens in substrate level phosphorylation in krebs cycle?
4C intermediate changed into another 4C intermediate
- socrinic acid - malic acid (ATP)
- malic acid - oxaloacetic acid (FADH2)
how is oxaloacetate reformed?
oxaloacetic acid is oxidised by NAD to form oxaloacetate for next cycle
