Aerobic Respiration- A2

The Mitochondria

This is a labelled Mitochondria. Mitochondria are where the link reaction (Matrix), the Krebs cycle (Matrix) and oxidative phosphorlyation (Inner Mitochondrial Membrane) take place.

Glycolysis

1. 
   
    Glucose (6 carbon) is made more reactive using 2ATP (Phosphorylation). Phosphate is added to it, as it lowers the activation energy for the reactions that follow.
2. 
   
   Each Phosphorylated glucose is split to form 2 Triphosphate molecules (3 carbon).
3. 
   
   The Triphosphates are oxidised by the removal of hydrogen to form PYRUVATE, the hydrogen is donated to an NAD co-enzyme, which makes red.NAD

Joining a phosphate to another molecule, e.g. ADP is phosphorlyation.

Substrate Level Phosphorylation: the phosphorylation of ADP + Pi = ATP using energy released from chemical reactions. So, the chemical energy used comes from the substrate, hence the name.

Link Reaction

PYRUVATE is oxidised by removing hydrogen. This is because of the DEHYDROGENASE enzyme.

PYRUVATE is DECARBOXYLATED. Decarboxylation is the removal of Carbon Dioxide (Decarboxylase Enzyme). Since a carbon has been removed, it goes from three carbons to two, an ACETYL group. This joins with a co-enzyme.

The Krebs Cycle

The Acetyl co-enzyme joins with a four carbon acceptor molecule to form a six carbon intermediate. The six carbon intermediate is then decarboxylated, and carbon dioxide is released, making it into a five carbon intermediate. At the same time, it is oxidised, loosing hydrogen. This hydrogen reduces an NAD co-enzyme, forming red.NAD which goes on to the electron transport chain.

The five carbon intermediate is decarboxylated, releasing carbon dioxide and making a four carbon intermediate. Enough energy is released to synthesise ATP by ADP+Pi = ATP. As well as this, the fout carbon intermediate is oxidised, donating a hydrogen to an FAD and 2NAD, reducing them too. The too move on to the electron transport chain. The four carbon acceptor goes back round in the cycle to join with an acetyl again.

Electron Transport Chain

In the electron transport chain, co-enzymes donate their electrons and protons (e- and H+). The electrons enter a chain of carriers, arranged in order of decreasing energy content, releasing energy, until they reach the final electron acceptor, molecular oxygen. Meanwhile, the H+ are actively transported through the ATP synthase enzyme, down a concentration gradient. The kinteic energy produced in the process gives enough energy to synthesis ADP + Pi => ATP. Also, the H+ joins on to the molecular oxygen with the electrons to form WATER.

Thoughts?
-Nin.