Chloroplast
/ˈklɔrəˌplæst/
Definition
Chloroplast is a specialized structure, called an organelle, found in plant cells and many algae. It contains chlorophyll, the green pigment that captures light energy for photosynthesis. Inside, chloroplast converts carbon dioxide and water into sugars and releases oxygen. Unlike other green cell parts, it is enclosed by membranes and has an internal system of flattened sacs where the light-capturing reactions occur.
Function in Plants
- Photosynthesis site: In green tissues, chloroplast captures light energy and uses it to make sugars from carbon dioxide and water. Those sugars fuel growth, flowering, fruit development, and many repair processes.
- Leaf color and vigor: High numbers in leaf cells support strong green color because chlorophyll is housed inside chloroplast. When they are damaged or underdeveloped, leaves may look pale or yellow and growth often slows.
- Light-driven movement: Many plants can shift chloroplast position inside cells as light changes. This helps improve light capture in low light and reduce stress from intense sun.
- Present beyond leaves: Chloroplast is most abundant in leaves, but it also occurs in other green parts such as young stems and unripe fruit. These tissues can contribute some photosynthesis when they receive enough light.
Related Terms
Chlorophyll
Chlorophyll is the green pigment in plant cells that absorbs light for photosynthesis, the process plants use to make…
Photosynthesis
Photosynthesis is the biological process in which plants, algae, and some bacteria use light energy to convert carbon…
Mesophyll
Mesophyll is the inner tissue of a leaf, located between the upper and lower epidermis. It consists mainly of…
Palisade mesophyll
Palisade mesophyll is a layer of tightly packed, elongated cells inside a leaf, usually just beneath the upper…
Carbon dioxide
Carbon dioxide is a gas in the air and a key raw material for photosynthesis, the process plants use to make sugars…
Gas exchange
Gas exchange refers to the movement of gases between a plant and the surrounding air, mainly carbon dioxide entering…
Etiolation
Etiolation is a plant growth condition caused by too little light. Stems become unusually long and weak, leaves stay…
Chlorosis
Chlorosis is a plant condition in which leaves lose green color because chlorophyll, the pigment used in…