Plastids
Plastid is a two-layered membrane-bound organelle found in the cells of plants that are involved in the synthesis and storage of food. They are fundamental for photosynthesis and the storage of food. Plastids are absent in animal cells. They consist of their own DNA and ribosomes and have the ability to divide.
A plastid containing green shade (chlorophyll) is called chloroplast while a plastid containing colors separated from green is known as a chromoplast. A plastid that needs colors is known as a leucoplast and is involved primarily in food capacity.
Types of plastids
Based on the morphology, structure, and color of plastids, they can be divided into the following types. Undifferentiated plastids are called “proplastids” which are found basically in meristematic tissues. Proplastids might form later into any of the different plastids.
- Chloroplasts
- Chromoplasts
- Gerontoplasts
- Leucoplasts
Chloroplasts
The most discussed type of plastid is the chloroplast. These organelles are liable for making plants green and creating energy for the cells and the plants overall. They are loaded up with heaps of thylakoid circles called grana. Each thylakoid film contains the green color chlorophyll, and the space inside the circle is known as the lumen. The liquid part that encompasses the grana and fills the chloroplast, similar to the cytoplasm of a phone, is known as the stroma.
Photosynthesis happens in the thylakoid stacks as the energy caught from the sun is siphoned across the layer from the stroma to the lumen. The hydrogen protons rush back across the film into the stroma, where ATP synthase changes over that energy into adenosine triphosphate (ATP), the cell’s energy cash. The ATP is incorporated into glucose atoms to be put away for some time in the future.
Chromoplasts
Chromoplasts are the other pigmented plastids that are all not green. These are tracked down in flowering plants, organic products, and mature leaves. At times chloroplasts are considered as chromoplast since they are pigmented, but the difference is that the green chlorophyll plays in photosynthesis.
Gerontoplasts
Gerontoplasts are old chloroplasts. The thylakoid films and the leftover chlorophyll are separated by gathering plastoglobuli, lipoprotein particles, in the stroma.
This progress from chloroplast to gerontoplast happens when the leaves go through senescence or decay with age. During the pre-winter months, the leaves change the tone and afterward bite the dust and tumble off. As the leaf passes on, the gerontoplasts are overwhelmed and processed via autophagosomes.
Leucoplasts
Leucoplasts are the non-pigmented organelles that are found in the non-photosynthetic pieces of the plant, like the roots.
They might turn out to be basically stockpiling sheds for starches, lipids, and proteins based on the plant’s needs. They are all the more promptly utilized for orchestrating amino acids and unsaturated fats.
There are three types of leucoplasts:
- Amyloplasts-Amyloplasts store and synthesize starch.
- Proteinoplasts-They stores the proteins and can be typically found in seeds.
- Elaioplasts-They help in storing fats and oils.
What are Plastids? – Class 9 Biology
The body of all living organisms is made up of cells. Based on the cellular organization, some organisms are made up of single cells which are unicellular, and more than one cell which is multicellular organisms. Single-cell is able to perform all the life processes like gaining food, respiration, excretion, growth, and reproduction.
A cell is a tiny mass of protoplasm which is surrounded by a membrane and is capable of performing all functions of life. A typical cell is formed of three parts.
- Plasma membrane-Outermost covering of the cell which is made up of lipids and proteins. It allows the entry and exit of some materials in and out of the cell.
- Nucleus-It is a spherical structure present in the center of the cell and is surrounded by cytoplasm.
- Cytoplasm-It is a jelly-like fluid that occupies the space between the cell membrane and the nucleus. A number of tiny components called cell organelles are present in the cytoplasm. All the chemical reactions and functions will take place in the cytoplasm.
- Cells have some special components called organelles. They are;
- Plastids, Vacuoles, Ribosomes, Lysosomes, Golgi bodies, Mitochondria, Endoplasmic reticulum.