respiration Flashcards
aerobic respiration
- requires oxygen
- produces carbon dioxide
- lots of ATP
anaerobic respiration
- absence of oxygen
- produces lactate or ethanol
- little bit of ATP
4 stages of aerobic respiration
- glycolysis
- link reaction
- krebs cycle
- oxidative phosphorylation
what is glycolysis
the splitting of the 6 carbon glucose into two 3 carbon pyruvate
what is the link reaction
3 carbon pyruvate molecule into a series of reactions which leads to the formation of acetylcoenzyme A (2 carbon molecule )
what is the kerbs cycle
the introduction of acetylocoenzyme A into a cycle of oxidation- reduction reactions that yield same ATP and a large quantity of NADH and FAD
what is oxidative phosphorylation
the use of electrons associated with reduced NAD and FAD, released from the krebs cycle to synthesize ATP with water produced as a by product
where does glycolysis take place
the cytoplasm
glycolysis process
- phosperation of the glucose to glucose phosphate
- spitting of the phosphorylated glucose
- oxidation of triose phosphate
- production of ATP
1st stage of glycolysis
- phosperation of the glucose to glucose phosphate
- glucose made more reactive by adding 2 phosphate molecules which provides energy to activate glucose and lowers the activation energy for enzyme controlled reaction
2nd stage of glycolysis
splitting of the phosphorylated glucose
- each glucose molecule is split into 3 carbon molecules (triose phosphate)
3rd state of glycolysis
oxidation if triose phosphate
- hydrogen is removed for the TP and transferred to NAD to form NADH
4th stage of glycolysis
production if ATP
- enzyme controlled reactions convert TP to pyruvate and 2 molecules of ATp are generated from ADP
energy yield from glycolysis
- 2 molecules of ATP
- 2 molecules of NADH
- 2 molecules of pyruvate
where does the link reaction take place
the matrix of the mitrocondria
link reaction process
- pyruvate is oxidized to acetate as it loses a co2 and 2 H+
- H+ used by NAD to form NADH, later used to produce ATP
- 2 carbon acetate combines with coenzyme A (COA) to produce acetylcoenzyme A
equation for the link reaction
pyruvate + NAD + COA = acetyl COA + NADH + CO2
where does the krebs cycle take place
the matrix of the mitochondria
process of the krebs cycle
- 2 carbon acetyl COA combines with a 4 carbon molecule to produce a 6 carbon molecule
- 6 carbon molecule loses CO2 and H+ making a 4 carbon molecule and 1 ATp as a result of substrate level pgosperaltiaotion
- 4 carbon molecule combines with a new acetyl COA to begin the cycle again
significance of the krebs cycle
- breaks down macromolecules into smaller ones (pyruvate to CO2)
- produces hydrogen atoms leading to the production of ATP
- regenerates the 4 carbon molecule that combines whit acetyl COA A which would accumulate otherwise
site of oxidative phosphorylation
mitrocondria
what is an electron transfer chain
the transfer of electron down a chain and energy is released
what happens during oxidative phosphorylation
- H+ ions produced during glycolysis and the Krebs cycle combine with NAD and FAD
- NADH and FADH donate the elctrons they are carring to the first moluecue in the elctron trasfer chain
- electrons pass along a chain of electon trasfer carrieer molucules in oxidation- reduction reactions, energy released causes the active transport H+ across the inner mitrodondrial memnbrane and into the intermenbranal space
respiration of lipids process
- lipid hydrolysed to glycerol and fatty acids
- glycerol is phosphorylated and converted into triose phosphate
- fatty acid is broken down into 2 carbon fragments and converted top acetyl CoA which enters the kerbs cycle
- produces carbohydrates and H+ atoms
- H+ atoms used to produce ATP during oxidation phosphorylation
respiration if protiens process
- protein hydrolysed into amino acids
- amino group removed before entering the respiration pathway
- 3 carbon compound converted to pyruvate
4.4 and 5 carbon compound converted into intermediates in the Krebs cycle
what happens in the absence of oxygen
the Krebs cycle or the electron transfer chain cannot continue as all the FAD and NAD will be reduced so no FAD or NAD can take up the H+ produced during the Krebs cycle
what is pyruvate converted into in plants and small microorganism
- ethanol
- carbon dioxide
what is pyruvate converted into in animals
lactate
word equation for production of ethanol in plants
pyruvate + NADH = ethanol + CO2 + oxidaised NAD
production of ethanol in plants
- pyruvate molecule formed at the end of gycolysis loses CO2 and accepts H+ form NADH to produce ethanol
word equation for production of lactate in animals
pyruvate + NADH = lactate + NADH
what is oxygen debt
when oxygen is used up more rapidly than it can be supplied
where is energy derived form in aerobic respiration
- substrate level phsoperalatstion in glycolyosis and Krebs cycle
- oxidative phosphorylation in the electron transfer chain
where is energy derived form in anaerobic respiration
gycolysis only
