Chromoplast


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Related to Chromoplast: Plastids

chromoplast

[′krō·mō‚plast]
(cell and molecular biology)
Any colored cell plastid, excluding chloroplasts.

Chromoplast

 

a pigmented intracellular organelle of plant cells; a type of plastid. Chromoplasts may be spherical, spindle-shaped, sickle-shaped, or irregularly polygonal. Their orange, yellow, or brownish coloring is caused principally by carotenoids. Chromoplasts are usually formed from green plastids—chloroplasts—as green chlorophyll pigments are destroyed in the process of the ripening of the fruits of certain plants, such as mountain ash, lily of the valley, and persimmon, and during the autumn yellowing of leaves. At this stage the protein-lipid membrane of the chloroplast system decomposes. The protein flows out of the plastids, while the lipid remains inside, dissolving the carotenoids, which color the plastids orange and yellow. In some instances the chromoplasts are formed from colorless plastids—leukoplasts—for example, in carrot roots.

REFERENCES

See references under PLASTIDS.
References in periodicals archive ?
Molecular oxygen and the state of geometric isomerism of intermediates are essential in the carotene desaturation and cyclization reactions in daffodil chromoplasts.
Later on, from pollen mitosis, chloroplasts further develop into chromoplasts by accumulating plastoglobules in the stroma (F ig.
Chromoplasts may begin as chloroplasts but lose chlorophyll and accumulate carotenoids to become chromoplasts during fruit ripening and other processes.
The production of the normal red colour of ripe fruit is due to the destruction of chlorophyll and the extensive accumulation of the carotenoids (lycopene and [beta]-carotene) while the chloroplasts are transformed into chromoplasts [4].
In the fruits and vegetables in which it is found, lycopene is naturally packaged in tiny structures called chromoplasts.
The carotenoids that impart yellow through orange colors are found within other small cell packets called chromoplasts.
rapid degradation of chlorophyll and a progressive accumulation of carotenoids mostly lycopene and [beta]-carotene as the chloroplast are transformed to chromoplasts [8, 9].