Confused and have questions? We’ve got answers. With Chegg Study, you can get step-by-step solutions to your questions from an expert in the field. If you rather get 1:1 study help, try 30 minutes of free online tutoring with Chegg Tutors.


From Biology-Online Dictionary | Biology-Online Dictionary
Jump to: navigation, search


noun, plural: chloroplasts

Chlorophyll-containing plastid found within the cells of plants and other photosynthetic eukaryotes


A plastid is an organelle that is commonly found in photosynthetic plants. Plastids are of different types depending on the presence of the pigment and metabolic functions. They may be chloroplasts, chromoplasts, and leucoplasts. A chloroplast is a plastid that contains high amounts of green pigment, chlorophyll. The chlorophyll pigments may be chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, and chrlorophyll f. Chlorophyll a is present in all chloroplasts. Other pigments that may be present (particularly in algal cells) are carotenoids and phycobilins.

The chloroplast has at least three membrane systems: outer membrane, inner membrane, and thylakoid system. The thylakoids are disk-shaped structures that function as the site of photosynthesis. It is because embedded in the thylakoid membrane is the antenna complex consisting of proteins, and light-absorbing pigments, including chlorophyll (the green pigment) and carotenoids. The chlorophyll is capable of absorbing light energy for use in photosynthesis. The high amounts of chlorophyll give chloroplast a green color, making it easily recognizable from the other plastids. Chloroplasts have their own DNA and it is called chloroplast DNA or cpDNA.

Word origin: Greek chloros (green) + plast (form or entity)


  • chloroplastid
  • green plastid
  • chloroleucite

See also: