12. respiration Flashcards
what are the four main stages of aerobic respiration
- glycolysis
- link reaction
- krebs cycle
- oxidative phosphorylation
summarize glycolysis
- phosphorylation of glucose to glucose phosphate, involves hydrolysis of two ATP
- splitting of phosphorylated glucose
- oxidation of triose phosphate, Hydrogen is removed by NAD into NADH
- production of ATP, TP into pyruvate, resulting in two ATP per pyruvate molecule
what is the yield from glycolysis
- two molecules of ATP (net)
- two molecules of NAD
- two molecules of pyruvate
why is glycolysis a ‘universal’ process?
- does not require membrane/ organelle
- does not require oxygen
- found across species
summarize the link reaction
pyruvate + NAD CoA = acetyl coA + CO2 + NADH
summarize the krebs cycle
- acetyl coA + 4c molecule = 6c molecule
- oxidised by NAD into NADH
- decarboxylated, releasing CO2
- FAD is reduced
- substrate level phosphorylation produces ATP
- = 4c molecule
name three co enzymes
NAD - respiration
FAD - krebs cycle
NADP - photosynthesis
four reasons why krebs cycle is important
- produces H+ ions needed for oxidative phosphorylation
- pyruvate into CO2
- regenerates 4c molecule, which will combine with acetyl CoA again
- used to manufacture fatty acids, amino acids and chlorophyll
what is the site of oxidative phosphorylation, krebs cycle and link reaction take place
mitochondria
Where does glycolysis take place?
cytoplasm of cell
Summarize oxidative phosphorylation
- Reduced NAD and FAD (from krebs) donate electrons and H+ ions to the first molecule of ‘electron transfer chain’
- electrons pass through ‘electron transfer chain’ through oxidation and reduction
- energy released by flow of electrons allows active transport of H+ ions into intermembrane space of mitochondria
- H+ diffuse through ATP synthase back into matrix, aiding in ATP synthesis
- H+ and e- combine with oxygen = h20
- oxygen is final electron acceptor
Why is energy from electrons from NAD and FAD released along a series of electron transfer molecules?
The greater energy released in a single step, the more energy is lost by heat.
Energy released little at a time = more available more useful purposes
How can lipids be used instead of glucose for respiration?
- hydrolysed into glycerol and fatty acids
- glycerol phosphorylated into triose phosphate, into glycolysis
- fatty acid into 2c fragments, into acetyl coA, krebs
How can proteins be used in respiration?
- Hydrolysed into amino acids
- ## Deamination removes amino group, this happens at different points in respiration depending on how many carbons they contain
why is oxygen needed for aerobic respiration?
Is the final electron acceptor, continues the flow of electron through transport chain.
