Please enable JavaScript.
Coggle requires JavaScript to display documents.
biology module 5.7 - aerobic respiration - Coggle Diagram
biology module 5.7 - aerobic respiration
respiration overview
word equation = glucose + oxygen ---> carbon dioxide + water + ATP
respiration is required for metabolic processes, endo/exocytosis, active transport
ATP molecule : adenine, ribose, 3 phosphate molecules
hydrolyse ATP to release energy
respiration occurs in the mitochondria :
ideal because mitochondria has own mDNA that produces enzymes required for respiration.
It also provides an isolated environment ideal conditions for respiration.
coenzymes in respiration
coenzyme = aids the function of enzyme by adding a chemical group from one molecule to another
coenzyme A = tracsfer acetate
NAD and FAD = transfer H+ and e- between molecules
link reaction
pyruvate enters the matrix (of the mitochondria) via active transport
decarboxylation :
removal of carbon dioxide from pyruvate molecule
becomes a 2 carbon molecule = acetyl group
oxidation :
removal of hydrogen
reduces NAD to NADH
binding of acetyl group and coenzyme A = acetylcoenzyme A
2 pyruvate molecules enter the link reaction (6 carbons in total)
glycolysis
occurs in the cytoplasm
products = 2 ATP, 2 NADH, 2 pyruvate
phosphorylation :
2 phosphate molecules are released from hydrolysis of one ATP molecule
2 phosphate molecules attach to glucose (6 carbon)
forms hexose bisphosphate
lysis :
hexose bisphosphate split into 2 molecules of triode phosphate (3 carbon molecule, 1 phosphate on the end)
phosphorylation :
another phosphate group is added to triose phosphate
forms triose bisphosphate (3 carbon and 2 phosphate molecule)
dehydrogenation :
triode bisphosphate molecules are oxidised (removal of hydrogen)
form 2 pyruvate molecules (3 carbon)
NAD accepts the removed hydrogen
forms NADH
example of
substrate level phosphorylation
- make ATP without the electron transport chain
krebs cycle
decarboxylation and dehydrogenation
citric acid undergoes decarboxylation
produces one co2 molecule
also undergoes dehydrogenation
NAD arrives, picks up the hydrogen group and reduces to NADH
5 carbon molecule is produced
decarboxylation and dehydrogenation
the 5 carbon molecules undergoes decarboxylation
produces one co2 molecule
also undergoes dehydrogenation
produces another NADH
results in a 4 carbon molecule
acetylcoenzyme A deliver an acetyl group
the acetyl group combines with oxaloacetate
this forms citrate/citric acid (6 carbons)
substrate level - phosphorylation
ADP molecule arrives and becomes phosphorylated
produces ATP
the cycle goes around twice for every one molecule of glucose - 2 pyruvate molecules produce 2 products from the links reaction that both enter the Krebs cycle
FAD reduces to form FAHD2
NAD reduces to NADH
return back as oxaloacetate
cycle continues again
oxidative phosphorylation
occurs in the inner membrane of the mitochondria
NADH and FADH2 release hydrogen atoms (the become oxidised)
these hydrogen atoms split into H+ and e-
the electrons move along the electron transport chain, loosing energy at each carrier protein (called NADH dehydrogenase)
H+ ions in the matrix are pumped into the inner membrane of the mitochondria
there is now a higher concentration of H+ ions in the inner membrane than outside
these H+ ions (protons) want to move down their electrochemical gradient, back into the matrix of the mitochondria
ATP synthase synthesises ATP from ADP and Pi
H+ ions move back to the matrix =
chemiosmosis
oxygen is the final electron acceptor
oxygen combines with H+ and e- (join together to form hydrogen)
hydrogen+oxygen = water