chloroplast

American  

[klawr-uh-plast, klohr-] / ˈklɔr əˌplæst, ˈkloʊr- /

noun

Botany.

1. a plastid containing chlorophyll.

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chloroplast British  

/ ˈklɔːrəʊˌplæst /

noun

1. a plastid containing chlorophyll and other pigments, occurring in plants and algae that carry out photosynthesis

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chloroplast Scientific  

/ klôr′ə-plăst′ /

1. A plastid in the cells of green plants and green algae that contains chlorophylls and carotenoid pigments and creates glucose through photosynthesis. In plants, chloroplasts are usually disk-shaped and can reorient themselves in the cell to vary their exposure to sunlight. Chloroplasts contain the saclike membranes known as thylakoids, which contain the chlorophyll and are arranged in stacklike structures known as grana. Besides conducting photosynthesis, plant chloroplasts store starch and are involved in amino acid synthesis. Like mitochondria, chloroplasts have their own DNA that is different from the DNA in the nucleus, and chloroplasts are therefore believed to have evolved from symbiont bacteria, their DNA being a remnant of their past existence as independent organisms.

2. See more at cell photosynthesis

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chloroplast Cultural  

1. A chlorophyll-containing organelle found in algal and green plant cells.

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Other Word Forms

• chloroplastic adjective

Etymology

Origin of chloroplast

First recorded in 1885–90; chloro(phyll) + -plast

Compare meaning

How does chloroplast compare to similar and commonly confused words? Explore the most common comparisons:

• chlorophyll vs. chloroplast

Explanation

The chloroplast is the place in a plant cell where photosynthesis happens. Your rose bushes have chloroplasts, but you don’t. Chloroplast is the combination of two biological terms, plastid (an organelle in a plant cell), and chloros, which means green. If you’re reading about plant biology, you’ll probably recognize chloros in chlorophyll, which is one of the pigments important to photosynthesis, which takes place in chloroplasts.

Example Sentences

Doing this under conditions of changing light colour and intensity, they could follow exactly what the cell's chloroplast was doing.

From Science Daily • Nov. 18, 2024

Using microscopy, they captured movies of the cell and its chloroplast and then fitted a network of nodes and edges to its complex shape using computer algorithms.

From Science Daily • Nov. 18, 2024

Previous evolutionary trees of plants built by scientists often used the genome of the chloroplast, the organelle that allows plants to perform photosynthesis.

From New York Times • May 11, 2024

To do this they needed to visualise the structural architecture of the chloroplast RNA polymerase.

From Science Daily • Mar. 4, 2024

The large chloroplast in each half is composed of six longitudinal plates, united at the axis of the cell.

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Campbell, Douglas Houghton