Carbon dioxide
/ˌkɑrbən daɪˈɑksaɪd/
Definition
Carbon dioxide is a gas in the air and a key raw material for photosynthesis, the process plants use to make sugars from light and water. It enters mainly through stomata, tiny pores in leaves. The carbon atoms in carbon dioxide become part of carbohydrates and other organic compounds, which helps distinguish it from oxygen, a different gas produced during photosynthesis.
Role and Significance
- Raw material for photosynthesis: In leaves, carbon dioxide is combined with water and light energy to make sugars. Those sugars supply energy and provide the carbon needed to build stems, roots, leaves, flowers, and fruits.
- Rate can limit growth: When light, water, and nutrients are adequate, low carbon dioxide can slow photosynthesis. This is one reason tightly sealed indoor spaces or poorly ventilated growing areas may reduce plant performance.
- Stomata regulate entry: Carbon dioxide enters mainly through stomata, the tiny pores on leaves. As stomata open for gas exchange, plants also lose water vapor, so carbon gain is closely linked to water use.
- Used in protected cultivation: In commercial greenhouses, added carbon dioxide may be used to increase photosynthesis when light and temperature are also suitable. The benefit is usually smaller or inconsistent in typical home growing conditions.
Related Terms
Photosynthesis
Photosynthesis is the biological process in which plants, algae, and some bacteria use light energy to convert carbon…
Stoma
Stoma refers to a microscopic pore in the epidermis, the outer cell layer of leaves and young stems. Each stoma is…
Transpiration
Transpiration is the plant process of losing water vapor to the air, mainly through tiny leaf pores called stomata, and…
Gas exchange
Gas exchange refers to the movement of gases between a plant and the surrounding air, mainly carbon dioxide entering…
Leaf
Leaf refers to a plant organ, usually flat and green, that grows from the stem or a branch and is specialized for…
Chloroplast
Chloroplast is a specialized structure, called an organelle, found in plant cells and many algae. It contains…
Mesophyll
Mesophyll is the inner tissue of a leaf, located between the upper and lower epidermis. It consists mainly of…
Respiration
Respiration is the metabolic process in plant cells that breaks down sugars, usually using oxygen, to release usable…