Question

Discuss the production of ATP and its use in the body

Answer 1

ATP is the universal cellular currency. It is essential for the living state. Exergonic reactions such as respiration release energy. This energy is coupled to produce ATP. Endergonic reactions such as photosyntehsis require energy. This energy is produced by ATP hydrolysis.
There are three methods of ATP production based on the energy source.
1. Substrate-level phsophorylation: Breakdown of a a high energy compound is coupled to ATP synthesis.
Ex: PEP + ADP -----> Pyruvate + ATP

2. Oxidative phosphorylation: Oxidation of a respiratory substrate provides energy for ATP syntehsis
Ex: Respiration

2. Photophosphorylation: Sun-light is the source for energy for ATP synthesis
Ex: Light reactions of photosynthesis

Both oxidative phosphorylation and photophosphorylation involve the electron transport chain.
The electron transport chain in respiration is located on the inner mitochondrial membrane.
The electron transport chain in photosynthesis is located on the thylakoid membranes of chloroplast.

The flow of electrons through the electron transport chain generates a proton gradient across the emembrane. This proton gradient is utilized by the ATP synthase complex to produce ATP.