What is respiration? How is it different from breathing?

Respiration and breathing are closely related processes, but they have distinct meanings and components.

Breathing:
Breathing is a mechanical process that involves the exchange of air between the atmosphere and the lungs. It primarily involves the movement of air in and out of the respiratory system. When you breathe in (inhale), your diaphragm and intercostal muscles contract, expanding the chest cavity. This creates a pressure difference that causes air to flow into the lungs, carrying oxygen with it. When you breathe out (exhale), the diaphragm and intercostal muscles relax, reducing the chest cavity's volume and expelling carbon dioxide-rich air from the lungs.

Respiration:
Respiration is a broader process that encompasses multiple stages and biochemical reactions that occur within cells to produce energy. There are two main types of respiration: aerobic respiration and anaerobic respiration.

Aerobic Respiration: This is the most common and efficient form of respiration. It takes place in the presence of oxygen and involves the breakdown of glucose (or other organic molecules) within cells to produce energy, carbon dioxide, and water. The energy produced is stored in molecules called ATP (adenosine triphosphate), which cells use for various functions. Aerobic respiration occurs in the mitochondria of cells and results in a much higher energy yield compared to anaerobic respiration.

The overall equation for aerobic respiration is:
Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)

Anaerobic Respiration: When there is a lack of oxygen, cells can still produce energy through anaerobic respiration. This process involves the incomplete breakdown of glucose, typically producing less energy than aerobic respiration. One common type of anaerobic respiration is fermentation, which occurs in various organisms, including some bacteria and human muscle cells during intense exercise. While anaerobic respiration is less efficient, it allows cells to continue generating energy when oxygen supply is limited.

In summary, breathing is the mechanical process of inhaling and exhaling air to exchange gases with the atmosphere, primarily oxygen and carbon dioxide. Respiration, on the other hand, refers to the overall process of generating energy within cells through various biochemical reactions, which can occur either in the presence (aerobic) or absence (anaerobic) of oxygen.