ATP - A2

This topic is scary horrible. :P

Energy Supply

ATP => Adenine Triphosphate

Energy supply has two key processes: Photosynthesis and Respiration

Photosynthesis - transfers light energy into chemical energy in organic molecules
CO2+H2O => (with light energy) O2 + C6H12O

Respiration - releases energy from organic molecules, e.g. glucose.
C6H12O + O2 => CO2 + H2O + Energy

We only ever have 5g of ATP in the body at any one time, and use 40kg of it in a single day.

Why do organisms need energy?

• Growth and Repair
• Muscle Contraction
• Active Transport (changes the chape of the protein carrier)
• Metabolism
• Maintainence of body temperature in birds and mammals.
• Movement.
• Building up of large molecules.

Why is it an energy carrier?

It is small, soluble, and therefore, easily transported around the body.

ATP is a specialised compound. Reactions are coupled of transferring energy releasing reactions and those that require energy.

Why not just use Glucose?

Glucose is too slow to break down. It breaks down in several stages, and because of this, looses a lot of energy as heat energy. It is wasted.

How does ATP store energy?

• The bonds between the phosphate groups are unstable and have a LOW activation energy.
• This means the phosphate bonds are easilt broken to release energy.
• Usually only the terminal phosphate group is removed. Energy is released in small usable amounts when ATP is hydrolysed to ADP + Pi

ATP is RE-synthesised from ADP + Pi by Phosphorylation, which is a condensation reaction.

• ATP is broken down in a single reaction, rapidly releasing energy to cell reactions, unlike glucose which, as previously said, needs to be broken down by a long series of reactions.
• ATP releases smaller more useable quantities of energies than Glucose does. (Plus heat is released with Glucose.)

Summary: Advantage of ATP as an energy carrier (Universal)

1. It is an immediate source of energy (small reaction.)
2. The phosphate bonds are unstable, have a low activation energy and are easily broken.
3. ATP is a small molecule, and is highly soluble, meaning it is easily transported anywhere in the body.

Thoughts?

-Nin. Comments would be really nice by the way. (: