Plastid/ Golgi Apparatuse, Definition,Type

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 Definition 

Plastid are membrane bounded organelles present in the cell of plant and photosynthetic protist. There are three main type of plastids. Chloroplast ,chromoplast leucoplasts.

Types

(1) Chloroplasts

Chloroplasts are the green plastid. They are present in the cell of green parts of plant and in algae they contain photosynthetic pigment for example the green chlorophyll. They carry out photosynthesis with the help of their pigments. They capture light energy convert it into chemical energy. They use this energy to prepare glucose. Like mitochondria chloroplasts are in closed by double membrane. On the internal side of inner membrane are in closed by double membrane. These stacks are called" grana".
The sac- like structure which make a granum called" thylakoid". A fluid called stroma surrounding the thylakoid. Like mitochondria chloroplasts also contain DNA ribosomes.

(2) Chromoplasts

Are the plastids that contain pigments such as carotenoids. These pigment are the bright colour. Chromoplast are present in the cell of flower petals and fruits. Chromoplast give colour of this part does help in pollination and dispersal of fruits and seeds.

(3) Leucoplasts 

Are the plastids that have no pigment. They are involved in the storage of starches, lipids and proteins. They are present in the cell of those part of plant were food stored. For example underground stems ,seeds roots etc.

Diagram

Golgi Apparatus 

In 1898 and Italian physician camilla Golgi discovered a set of flattened sacs in the cytoplasm. These flattened and sacs called cisternae, are stacked over each other and make a structure known as Golgi Apparatus. It is found in both plant and animal cell it modified protein coming from rough endoplasmic reticulum and packs them into small membrane bounds called Golgi vesicles. These sacs are called kept in cell or are transported to exterior in the form secretions.
In "1906" Golgi was awarded Nobel prize for physiology and medicine.

Diagram 


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