The Structure and Function of cell Organelles
A cell is a structural and functional unit of life. A microscope is required to study cell structure. Scientist Robert Hook First studied the cell structure in the year 1665 using a self designed microscope. A cell having following Structure and Function of cell Organelles.
Major Cell organelles are as follows
1.Cell Membrane- Cell membrane enclose the cell and regulates the in and out flow of substance. It is also known as plasma membrane which form the covering of animal cell. It is elastic, living, double layer and permeable membrane. It is made up of protein and lipid molecules.
Function-It regulated movement of molecules inside and outside the cell.
2. Cell Wall – The outer layer in the plant cell is called cell wall. The cell wall lies outside the plasma membrane. The plant cell wall is mainly composed of cellulose and chitin. Cellulose is a complex substance and provides structural strength to plant.
Function-When a living plant cell loses water through osmosis the is shrinkage or contraction of the contents of the cell away from the cell wall.
3. Protoplasm –The whole fluid present inside plasma membrane is protoplasm. Protoplasm is made up of various chemical substance like water ,ions, salt and organic molecule .it is the living pat of cell. Protoplasm is divided into two parts.
i) Cytoplasm – The fluid found outside the nuclear membrane.
ii) Nucleoplasm – The fluid found inside the nuclear membrane.
4. Nucleus- It is the most important organelle of a cell and usually lies in the center. It may lie in the periphery. Its basic function is cell division and multiplication. The nucleus has a double layered covering called nuclear membrane. The nucleus contains chromosomes .chromosome contain information for inheritance of features form parents to next generation in the form of DNA ( Deoxyribo Nucleic Acid) molecules.
Function- It controls all activity of cells. So it is also known as “control room “of cell. Chromatin transmits hereditary characters from parent of their offspring.
5. Mitochondria– Discovered by Altman in the year 1886.these are cylindrical rod shaped or spherical structure found in cytoplasm. It is surrounded by double layered membrane. Inner membrane has many fold called cristae. The fluid present inside mitochondria is called matrix, which contain many enzyme and co-enzyme.
Function- Mitochondria is the respiratory site of cellular respiration. Mitochondria synthesize energy rich compound ATP (Adenosine Triphopshate) ATP is known as the energy currency of the cell. Mitochondria are known as the Powerhouse of the cell.
6. Golgi Bodies-Golgi bodies are made up of group of tubes, vesicles and vacuoles. These are also called as Golgi apparatus. Golgi apparatus discovered by scientist Camilo Golgi.
Function- It functions include the storage, processing modification and packaging of products in vesicles. It also involved in the synthesis of cell wall, plasma membrane and lysosomes.
7. Ribosome- Discovered by Palade. Small granules like structure found attached to the endoplasmic reticulum or in Free State. It is made up of ribonucleic acid (RNA).
Function- Ribosome helps in protein Synthesis.
8. Lysosomes – Lysosomes are like structure bounded by single membrane and contain hydrolytic enzyme. These enzymes made by RER. Lysosomes discovered by De Duve.
Function- it helps in intercellular digestion. The enzyme found in lysosomes may digest the entire ell. Therefore lysosomes also known as the “suicide bags “ of a cell.
9. Endoplasmic Reticulum (ER)- the endoplasmic reticulum (ER) is a large network of tubules like structure found in cytoplasm .it is attached with the nucleus on one side and on other side it is joined with plasma membrane . There are two types of ER-
i ) Rough Endoplasmic reticulum (RER)- Rough endoplasmic reticulum looks rough under a microscope because it has particles called ribosome attached to its surface.
Function- RER concerned with protein synthesis and transport. RER developed in protein exporting cells (ex. pancreatic cells and Liver) .
ii ) Smooth Endoplasmic reticulum (SER) – Smooth endoplasmic reticulum looks smooth under a microscope because it has free ribosome particles .its surface.
Function- Smooth Endoplasmic reticulum helps in synthesizes and transports lipids and steroids. Some kinds of smooth E. R transport proteins from the rough E. R. And still other kinds break down energy rich glycogen and fats.
Function- Endoplasmic reticulum (ER) helps in the distribution of material. It forms supporting framework of cell.
10. Plastids- Plastids are present only in plant cells. There are three types of plastids-
i) Chromoplast (colored plastids) –It provides various colors to the plant.
ii) Chloroplasts– Plastids containing the pigment chlorophyll are known as chloroplast. Chloroplasts are important for photosynthesis in plants. It known as “kitchen of the cell”.
iii) Leucoplast (white or colorless plastids) – Leucoplasts are primarily organelles. It stores the food in the form of starch, fat and protein.
11. Centrosome– it is Located in the cytoplast adjacent to the nucleus and takes part in cell division.
12. Vacuoles- Vacuoles are storage sacs for solid or liquid contents .vacuoles are small sized in animal cells while plant cells have very large vacuoles.
Many substances of importance in the life of the plant cell are stored in vacuoles. These include amino acids and some proteins.
Function- it helps in osmoregulation .It stores toxic metabolic waste.