● `color{brown}("Plastids")` are found in all plant cells and in `color{violet}("euglenoides.")`
● These are easily observed under the `color{violet}("microscope as they are large.")`
● They bear some specific `color{violet}(" pigments,")` thus imparting specific `color{violet}("colours to the plants")`
● Based on the type of `color{violet}("pigments plastids")` can be classified into `color{brown}("chloroplasts, chromoplasts")` and `color{brown}("leucoplasts.")`
● The `color{brown}("chloroplasts")` contain `color{brown}("chlorophyll")` and `color{brown}("carotenoid pigments")` which are responsible for trapping light energy essential for `color{violet}("photosynthesis.")`
● In the `color{brown}("chromoplasts")` fat soluble `color{brown}("carotenoid")` pigments like `color{brown}("carotene, xanthophylls")` and others are present.
● This gives the part of the plant a yellow, orange or red colour.
● The `color{brown}("leucoplasts")` are the colourless plastids of varied `color{violet}("shapes and sizes")` with stored nutrients:
`star` `color{brown}("Amyloplasts ")`store carbohydrates (starch), e.g., potato;
`star` `color{brown}("Elaioplasts")` store oils and fats whereas
`star` `color{brown}("Aleuroplasts")` store proteins.
● Majority of the `color{violet}("chloroplasts")` of the green plants are found in the `color{brown}("mesophyll cells")` of the leaves.
● These are `color{violet}("lens-shaped, oval, spherical, discoid")` or `color{violet}("even ribbon-like organelles")` having variable length (5-10mm) and width (2-4mm).
● Their number varies from 1 per cell of the `color{violet}("𝘊𝘩𝘭𝘢𝘮𝘺𝘥𝘰𝘮𝘰𝘯𝘢𝘴")`, a green alga to 20-40 per cell in the mesophyll.
● Like `color{violet}("mitochondria,")` the `color{violet}("chloroplasts")` are also double membrane bound.
● Of the two, the `color{violet}("inner chloroplast")` membrane is relatively less permeable.
● The space limited by the `color{violet}("inner membrane")` of the `color{violet}("chloroplast")` is called the `color{brown}("stroma.")`
● A number of `color{violet}("organised flattened membranous")` sacs called the `color{brown}("thylakoids,")` are present in the `color{violet}("stroma.")`
● `color{violet}("Thylakoids")` are arranged in stacks like the piles of coins called `color{brown}("grana (singular: granum)")` or the `color{brown}("intergranal thylakoids.")`
● In addition, there are `color{violet}("flat membranous tubules")` called the `color{brown}("stroma lamellae ")`connecting the thylakoids of the `color{violet}("different grana.")`
● The membrane of the `color{violet}("thylakoids enclose")` a space called a `color{brown}("lumen. ")`
● The `color{violet}("stroma")` of the `color{violet}("chloroplast")` contains enzymes required for the synthesis of carbohydrates and proteins.
● It also contains small, double-stranded circular DNA molecules and ribosomes.
● `color{violet}("Chlorophyll pigments")` are present in the `color{violet}("thylakoids.")`
● The `color{violet}(" ribosomes")` of the `color{violet}("chloroplasts")` are smaller (70S) than the cytoplasmic ribosomes (80S).
● `color{brown}("Plastids")` are found in all plant cells and in `color{violet}("euglenoides.")`
● These are easily observed under the `color{violet}("microscope as they are large.")`
● They bear some specific `color{violet}(" pigments,")` thus imparting specific `color{violet}("colours to the plants")`
● Based on the type of `color{violet}("pigments plastids")` can be classified into `color{brown}("chloroplasts, chromoplasts")` and `color{brown}("leucoplasts.")`
● The `color{brown}("chloroplasts")` contain `color{brown}("chlorophyll")` and `color{brown}("carotenoid pigments")` which are responsible for trapping light energy essential for `color{violet}("photosynthesis.")`
● In the `color{brown}("chromoplasts")` fat soluble `color{brown}("carotenoid")` pigments like `color{brown}("carotene, xanthophylls")` and others are present.
● This gives the part of the plant a yellow, orange or red colour.
● The `color{brown}("leucoplasts")` are the colourless plastids of varied `color{violet}("shapes and sizes")` with stored nutrients:
`star` `color{brown}("Amyloplasts ")`store carbohydrates (starch), e.g., potato;
`star` `color{brown}("Elaioplasts")` store oils and fats whereas
`star` `color{brown}("Aleuroplasts")` store proteins.
● Majority of the `color{violet}("chloroplasts")` of the green plants are found in the `color{brown}("mesophyll cells")` of the leaves.
● These are `color{violet}("lens-shaped, oval, spherical, discoid")` or `color{violet}("even ribbon-like organelles")` having variable length (5-10mm) and width (2-4mm).
● Their number varies from 1 per cell of the `color{violet}("𝘊𝘩𝘭𝘢𝘮𝘺𝘥𝘰𝘮𝘰𝘯𝘢𝘴")`, a green alga to 20-40 per cell in the mesophyll.
● Like `color{violet}("mitochondria,")` the `color{violet}("chloroplasts")` are also double membrane bound.
● Of the two, the `color{violet}("inner chloroplast")` membrane is relatively less permeable.
● The space limited by the `color{violet}("inner membrane")` of the `color{violet}("chloroplast")` is called the `color{brown}("stroma.")`
● A number of `color{violet}("organised flattened membranous")` sacs called the `color{brown}("thylakoids,")` are present in the `color{violet}("stroma.")`
● `color{violet}("Thylakoids")` are arranged in stacks like the piles of coins called `color{brown}("grana (singular: granum)")` or the `color{brown}("intergranal thylakoids.")`
● In addition, there are `color{violet}("flat membranous tubules")` called the `color{brown}("stroma lamellae ")`connecting the thylakoids of the `color{violet}("different grana.")`
● The membrane of the `color{violet}("thylakoids enclose")` a space called a `color{brown}("lumen. ")`
● The `color{violet}("stroma")` of the `color{violet}("chloroplast")` contains enzymes required for the synthesis of carbohydrates and proteins.
● It also contains small, double-stranded circular DNA molecules and ribosomes.
● `color{violet}("Chlorophyll pigments")` are present in the `color{violet}("thylakoids.")`
● The `color{violet}(" ribosomes")` of the `color{violet}("chloroplasts")` are smaller (70S) than the cytoplasmic ribosomes (80S).