Bioenergetics:

Bioenergetics is the study of energy relationships and energy transformations (conversions) in living organisms.

Bioenergetics and the Role of ATP:

Organisms obtain energy by metabolizing the food they eat or prepare. The food contains potential energy in its bonds. When these bonds are broken down, a large amount of kinetic energy is usually released. Some of this energy is stored in the form of potential energy in the bonds of ATP molecules while the rest escapes as heat. The potential energy stored in ATP is again transformed into kinetic energy to carry out life activities.

Bioenergetics and Oxidation-Reduction Reactions:

For all life processes, oxidation-reduction reactions are the direct source of energy Oxidation-reduction reactions (Redox reactions) involve the exchange of electrons between atoms.

Oxidation:

The loss of electrons is called oxidation.

Reduction:

The gain of electrons is called reduction.

Role of Electrons in Bioenergetics:

Electrons can be an energy source. It depends upon their location and arrangement in atoms. For example; when they are present in oxygen, they make a stable association with oxygen atoms and are not a good energy source. But if electrons are dragged away from oxygen and attached to some other atom e.g. carbon or hydrogen, they make an unstable association. They try to move back to oxygen and when this happens, energy is released.

Role of Redox Reactions:

In living, organisms’ redox reactions involve the loss and gain of hydrogen atoms. We know that a hydrogen atom contains one proton and one electron. It means that when a molecule loses a hydrogen atom, it actually loses an electron, and similarly, when a molecule gains a hydrogen atom, it gains an electron.