Cellular Respiration

Cellular respiration is the process by which cells in plants, animals and fungi break down sugar in the presence of oxygen into carbon dioxide and water, releasing energy.
This energy is then utilised to generate adenosine triphosphate (ATP), which provides the energy required for various activities in the cell.
It is an exothermic process, which means it releases heat.

The Stages of Cellular Respiration

Cellular respiration involves four main stages: glycolysis, link reaction, Krebs cycle (also known as the citric acid cycle), and the electron transport chain.
Glycolysis happens in the cytoplasm of the cell, where glucose (from the food we eat) is broken down into pyruvate. This process produces 2 ATP molecules and does not require oxygen, hence is also known as anaerobic respiration.
In the link reaction, pyruvate is converted into Acetyl coenzyme A (Acetyl CoA) in the mitochondria. This process also releases carbon dioxide.
Krebs cycle or the citric acid cycle, is the next stage where Acetyl CoA is processed to produce ATP and carbon dioxide. In this cycle, electrons are also transported to the final stage of the respiration process.
In the electron transport chain, ATP is produced in large amounts (around 32 molecules of ATP) and water is formed when the transported electrons combine with oxygen.

Function and Importance of Cellular Respiration

Cellular respiration is essential for life as it provides the energy needed for all the biological processes that keep an organism alive and functioning.
Apart from energy production, it plays a vital role in the removal of excess carbon dioxide from the cell, preventing a detrimental build-up.
The process also serves as a precursor to other essential cell functions such as protein synthesis and cell division.

Remember, cellular respiration is not just about providing energy, but also maintaining the balance of carbon dioxide and oxygen in the body, among other roles. It is a complex process involving multiple steps, each contributing to the effective functioning of our cells and overall health.