Respiration

Basic Process

Respiration is a biochemical process in which living organisms obtain energy from organic substances (like glucose). It involves the breakdown of food molecules to release energy, which is then used for various life processes. This process occurs continuously in all living cells.

Word Equation:

Glucose + Oxygen → Carbon Dioxide + Water + Energy

Respiration as a Process which Releases Energy

Respiration is an exothermic process, meaning it releases energy. This energy is captured in the form of ATP (Adenosine Triphosphate) molecules, which serve as the main energy currency of the cell. This energy is vital for activities such as growth, movement, reproduction, and maintaining body temperature.

Respiration in Plants

Plants also respire, taking in oxygen and releasing carbon dioxide, just like animals. Respiration in plants can be of two types:

1. Aerobic Respiration

• Basic Concept: Occurs in the presence of oxygen. It is a complete breakdown of glucose into carbon dioxide and water, releasing a large amount of energy.
• Word Equation: Glucose + Oxygen → Carbon Dioxide + Water + Energy (large amount)
• Examples: Most plants and animals perform aerobic respiration.

2. Anaerobic Respiration

• Basic Concept: Occurs in the absence or limited supply of oxygen. It is an incomplete breakdown of glucose, releasing a smaller amount of energy compared to aerobic respiration.
• Word Equation (in plants/yeast - alcoholic fermentation): Glucose → Ethanol + Carbon Dioxide + Energy (small amount)
• Examples: Some bacteria, yeast, and plant tissues under waterlogged conditions (e.g., roots in waterlogged soil).

Respiration and Photosynthesis in Plants

These two processes are complementary and vital for plant life, but they are distinct.

Difference in Both Processes