→The correct question should be 'draw the reason that you sometimes get 30 ATPs out of cellular respiration instead of 32'
Answer :Glucose is high energy-rich ccompound. Therefore to initiate the breakdown down of bonds in glucose for phosphorylation of glucose; to obtain Pyruvate for ATPs synthesis 2ATPs must be supplied...
The 2 ATPs were ‘borrowed’ – to convert
1. Glucose to fructose phosphate,
2. And later to fructose bisphosphate. This is phosphorylation of glucose.
The end product of this reaction is PYRUVATE. THE NET ATPs produced is 4ATPs per molecule of glucose, but the total gained ATPs is 2, because the 2ATPs 'borrowed' from the phosphorylation must be paid back. This is substrate level phosphorylation and it takes place in the cytoplasm without OXYGEN.
Link reaction is the process of conversion of pyruvate from glycolysis to Acetyl CoA .It is the reaction pathway which linked glycolysis with citric acid cycle, in cellular respiration in the presence of oxygen. If no oxygen is available, link reaction does not take place; rather the pyruvate moves to fermentation
It involves decarboxylation, and dehydrogenation (with NADH) of 3Cpyruvate, and reaction with Coenzyme A to form 2C-acetyl CoA,
The 2C-acetyl Coenzyme A reacted with 4c oxaloacetate in the mitochondrial matrix to form 6C citrate. This involves decarboxylation and dehydrogenation with NADH.
The citric cycle continues on till 2ATPs are produces with each glucose molecule; until the 4 molecule oxaloacetate is reproduced. 4CO2, 6NADH, 2FADH2 and 2ATPs molecules per molecule of glucose are produced.
The NADH and FADH2 fetched Hydrogen into the mitochondrial matrix where it is split to
Protons and electrons.
The electrons are transferred by protein carries in the matrix. As these electrons moved through proteins carriers of different energy levels ENEGY is released;and used to pump protons from the matrix across the intramembrane to the cytosol. The proton gradient drives protons down the concentration gradient through the hydrogen channel of ATPase synthase. The enzyme tapped the energy from the protons to synthesise ATP from ADP.
This is oxidative phosphorylation.it produces 28ATPs
The balanced sheet of ATP per molecule of glucose =
→4ATPS from glycolysis ( 2ATPs used ).
→2ATPs from Citric Acid
→28 ATPs from Oxidative phosphorylation.
⇒Total =34 - (2ATPs) used =30ATPs.
Explanation:
