Respiration

Glycolysis

The triose phosphate is oxidised and 2 molecules of pyruvate are formed move to the inner matrix of the mitochondria to be used in the link reaction.
CoenzymeNAD collects the hydrogen ions and they are taken to the ETC.
4ATP are produced in this reaction so there is a net gain of 2ATP

Glycolysis takes place in the cytoplasm of cells
It is the first stage of both aerobic and anaerobic respiration as it does not require oxygen.
If no oxygen present NAD reduces pyruvate to lactic acid.

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One molecule of Co2 is removed from the pyruvate leaving a 2 carbon molecule acetate.
Acetate then combines with coenzyme A to produce acetyl coenzyme A.
Another oxidation reaction occures and NAD collects hydrogen ions so NAD is reduced.
Reduced NAD moves to the electron transport chain.

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Acetyl coenzyme A from the link reaction combines with oxeloacetate to form a 6 carbon molecule citrate. A
The citrate is then converted to a 5 carbon molecule and CO2 is given off as waste gas.
Both coenzymes NAD and FAD are reduced to form reduced NAD and FAD, which carry hydrogen ions to the ETC.
The 5 carbon compound is converted to a 4 carbon compound and ATP and CO2 are released.

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hydrogen atoms are released from the reduced NAD and FAD.
The H atoms split into protons and electrons
the electrons move down the electron transport chain releasing energy as they go.
The energy released is used to push protons between the inner and outer membrane of the matrix of the mitochondria.
This creates and elctro chemical gradient and the protons move back down the ETC.
this creates an electro potential energy which fuels ATPsynthase make ATP from ADP.
the protons and electrons recombine to reform hydrogen and this combines with oxygen
Oxygen is said to be the terminal electon acceptor.

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