Bioenergetics

The quantitative study of energy relationships & conversions in different forms is called Bioenergetics.

For example, the solar energy is converted into chemical energy by the plants in the process of photosynthesis. Similarly, this chemical energy of utilized in to some metabolic reaction producing heat of some other form of energy etc.

Thus these energy conversions obey the laws of thermodynamics.

How and Why Organisms Need Energy?

How?                                  

For any organism, the ultimate source of energy is its food obtained by any means. This food is when metabolized in the body release some energy which was previously present in the form of potential Energy in the bonds of food particles/ molecules. When the food is catabolised this potential energy is converted to kinetic energy. Some of this released energy is converted to chemical energy (ATP) so that it can be stored in the body. This chemical energy is actually a form of potential energy. So when body requires energy for performing some task/ activity, this potential energy is converted again to kinetic energy by the hydrolysis of ATP.

Why?

All organisms need free energy for performing different activities & running the various processes of metabolism.

For Example

•          i.            For the synthesis of proteins.
•        ii.            Active Transport.
•       iii.            Phagocytosis.
•      iv.            Pinocytosis.
•        v.            Mechanical work.
•      vi.            Maintaining temperature of body.
•     vii.            Nerve impulse etc.

Role of Redox Reactions

Redox

The term Redox is a combination of two processes Reduction. So, a Redox reaction involves both these processes simultaneously.

Oxidation Reduction

Oxidation-reduction can be defined as

•          i.            Gain of Oxygen.
•        ii.            Loss of Hydrogen.
•       iii.            Loss of electrons.

Whereas reduction is referred to

•          i.            Loss of Oxygen.
•        ii.            Gain of Hydrogen.
•       iii.            Gain of electrons.

These two processes are constantly involved in flow of energy. Is the energy generation & utilization go in cyclic manner by manner by these reactions.

Energy Exchange & electron Exchange

If the electrons are lost from an atom & gained by some other atom, they carry the energy by some other atom. This transfer of energy may in turn be utilized to make a stable association between two atoms.

Every atom possesses both proteins & electrons.

For example, Hydrogen atom has one proton & one electron and as already mentioned “loss or gain of hydrogen atoms is also called Redox Reaction”. So, when a molecule loses a hydrogen atom, it actually loss an electron & vice versa when a molecule gains a hydrogen atom.