Site of
photosynthesis
The site of
photosynthesis in a a cell of the leaf are chloroplasts. Chloroplasts are the
organelles in the cells of green plants which contain chlorophyll and where
photosynthesis takes place. Chloroplasts can be seen easily by using a light
microscope. In a cross section of a leaf, chloroplasts can be seen as numerous
disc-like organelles in the photosynthesis cells of the palisade tissue just
below the upper epidermis.
In the structure of a
leaf we can see that the middle layers in the leaf contain photosynthesis cells
called mesophyll cells. These cells contain more chlorophyll than other plant
cells. A typical photosynthesis cell of a green leaf may contain 100 or more
tiny chloroplasts in it, and a whole leaf may contain many thousands of
photosynthesis cells. Carbon dioxide needed for photosynthesis enters from the
air into the leaf through the stomata in its surface, and then diffuses into
the mesophyll cells and reaches the chloroplasts. water is carried to the leaf
by xylem vessels and passes into the mesophyll cells by diffusion and reaches
the chloroplasts.
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