The process complementary to respiration is photosynthesis.

Photosynthesis
Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. It is an essential process for the survival of plants and other organisms that depend on them for food.

Process
Photosynthesis takes place in the chloroplasts of green plant cells, particularly in the leaves. The process involves the following steps:

1. Light Absorption: Chlorophyll, the green pigment in plants, absorbs light energy from the sun.

2. Conversion of Light Energy: The absorbed light energy is converted into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate).

3. Water Splitting: Water molecules are split into hydrogen ions (H+), oxygen atoms (O), and electrons (e-) through a process called photolysis.

4. Release of Oxygen: The released oxygen atoms combine to form molecular oxygen (O2) and are released into the atmosphere as a byproduct.

5. Carbon Dioxide Fixation: Carbon dioxide (CO2) from the atmosphere enters the chloroplasts and combines with the hydrogen ions and electrons to form glucose (C6H12O6) through a series of chemical reactions known as the Calvin cycle.

Importance
Photosynthesis is crucial for the following reasons:

1. Production of Oxygen: Photosynthesis is responsible for the oxygenation of the atmosphere, providing breathable air for humans and other organisms.

2. Food Production: Photosynthesis is the primary source of food production in plants. Glucose produced during photosynthesis is used as an energy source for growth and development.

3. Energy Storage: Glucose produced through photosynthesis is stored as starch in plants, serving as a long-term energy reserve.

4. Carbon Dioxide Reduction: Photosynthesis helps reduce the concentration of carbon dioxide in the atmosphere, mitigating the greenhouse effect and climate change.

5. Ecological Balance: Photosynthetic organisms form the foundation of most ecosystems, providing energy and nutrients for other organisms through the food chain.

Overall, photosynthesis is the process complementary to respiration as it utilizes carbon dioxide and releases oxygen, while respiration utilizes oxygen and releases carbon dioxide. Together, these processes maintain a balance of gases in the atmosphere and support life on Earth.

As in the process of photosynthesis plants inhale carbon-dioxide for