Aerobic Respiration Flashcards
what are the 4 stages of respiration?
- glycolysis
- link reaction
- Krebs Cycle
- oxidative phospharylation
what are the 4 stages of glycolysis?
- phosphorylation of glucose to glucose phosphate
- splitting of glucose phosphate
- oxidation of triose phosphate
- production of ATP
what happens during stage 1 of glycolysis?
- glucose is made more reactive by the addition of 2 phosphate molecules (phosphorylation)
- hydrolysis of 2 ATP molecules releases 2 phosphate molecules and 2 ADP molecules
what happens during the second stage of glycolysis?
- splitting of phosphorylated glucose
- each glucose molecule is split into 2 3 carbon molecules called triose phosphate
what happens during the third stage of glycolysis?
- hydrogen is removed from each of the 2 triose phosphate molecules and transferred to NAD to form reduced NAD
- triose phosphate is oxidised
what happens during the final stage of glycolysis?
- enzyme-controlled reactions convert each triose phosphate molecule into another 3 carbon molecule called pyruvate
- two molecules of ATP are regenerated from ADP
where does glycolysis occur?
cytoplasm
where does pyruvate go after glycolysis?
actively transported into the mitochondrial matrix through a transport protein
what is the yield from glycolysis?
- two molecules of ATP
- two molecules of reduced NAD
- two molecules of pyruvate
what type of phosphorylation takes place in glycolysis?
substrate-level phosphorylation
why is the net production of ATP 2 in glycolysis?
4 molecules of ATP produced but 2 are used up in initial phosphorylation of glucose
4-2=2
what happens during the link reaction?
- pyruvate is oxidised to acetate(2C). This reaction involved the decarboxylation of pyruvate (loses a CO2) and the dehydrogentaion of pyruvate (loses hydrogens)
- this happens to each pyruvate produced by the glucose
- the hydrogens are accepted by NAD to form reduced NAD which is later used to produce ATP
- 2 carbon acetate combines with coenzyme A to form acetylCoA (2C- acetyl coenzyme A)
what is the summary equation for the link reaction?
pyruvate + NAD + CoA –> acetyl CoA + reduced NAD + CO2
where does the link reaction take place?
mitochondrial matrix
what can ATP be used for?
- active transport
- mitosis
- DNA replication
what happens during the Krebs Cycle?
- acetyl CoA (2C) from the link reaction combines with 4C molecule (oxaloacetate) to form a 6C molecule (citrate) CoA goes back to the link reaction to be used again.
- citrate loses CO2(decarboxylation) and hydrogen(dehydrogentation) (hydrogen accepted by NAD to form NADH) to form a 5C molecule
- 5C molecule is then 4C molecule (oxaloacetate). Decarboxylation and dehydrogenation occurs produces one molecule of reduced FAD and two molecules of reduced NAD. ATP produced from direct transfer of phosphate from intermediate ADP compound (substrate level phosphorylation)
- citrate is converted back to oxaloacetate
what are the products of Krebs cycle and where do they go?
- 1 CoA = reused in link reaction
- oxaloacetate = regenerated for use in next Krebs cycle
- 2 CO2 = released as a waste products
- 1 ATP = used for energy
- 3 reduced NAD = oxidative phosphorylation
- 1 reduced FAD = oxidative phosphorylation
what is the order of events from 5 carbon molecule to 4 carbon molecule?
- removes CO2
- NAD –> reduced NAD
- ADP + Pi –> ATP
- FAD –> reduced FAD
- NAD –> reduced NAD
