functions of the plant and animal cell

Concept of the cell

The cell is the smallest structural unit of the organization of the living body. The organisms composed of a single cell are called unicellular organisms and  those of many cells are called multicellular organisms. Cells perform different functions in the body.

For example - The transportation of oxygen is done by red blood cells.   Transmission of impulses is done by neurons. Accordingly, the smallest bio unit that is adapted to perform a particular function is the cell. So it is clear that the structural and functional unit of life is the cell. The cells differ from one another from their shape, size and function. Except few occasions, mostly cells are not visible to the naked eye. Therefore they have to be observed using the light microscope. 

Typical cell The small structures present within the cell to perform different functions are known as organelles.The types of organelles and the number of them differ according to the function performed by the cell. The cell prepared by including all the organelles is known as the typical cell. In the living world such cells do not exist. But cells with a certain number of organelles of the typical cell can be found in living organisms.

All animal cells are covered by a plasma membrane or a cell membrane. It is a live semi permeable membrane as well as a selective permeable membrane. There is a centralized nucleus in an animal cell. The cytoplasm is a gelatinous material. The outer covering of the plant cell is the cell wall . It is made up of  cellulose. Inner to the cell wall is the plasma membrane. At the center of plant cell is a large vacuole. Generally there are no such vacuoles in animal cells. Animal cells as well as plant cells possess different organelles that perform different functions. Most of the above organelles cannot be observed through the light microscope. Therefore the electron microscope should be used. Below are the typical plant and animal cells created based on electron  microscopic information.

Cell wall

The outer most covering of the plant cell is the cell wall. It is a dead structure. The main constituent of it is cellulose. The main functions of the cell wall are , to maintain the shape of the cell, support and protection of the cell.

Plasma Membrane

Plasma membrane is present interior to the cell wall of plant cells.The boundary of the animal cell is the plasma membrane. It is made up of phospholipids and proteins. Plasma membrane is a semi permeable membrane. The main function of it is to enclose the cell, allow entry of water, ions, some molecules and thereby control the entry and exit of materials into and out of the cell. Plasma membrane is also known as cell membrane.

Cytoplasm

The gelatinous liquid part of the cell excluding organelles is known as the cytoplasm. Inorganic and organic substances are present in it. The functions of the cytoplasm are to maintain a shape to the cell, bear cell organelles and carryout different metabolic processes. The structures submerged in the cytoplasm are named as organnells. some organelles are surrounded by cell membranes.

Nucleus

Nucleus is the main organelle in a cell. It is surrounded by a nuclear envelope. One or two nucleolus and the chromatin body are present inside the nucleus. During cell division, the chromatin body converts into chromosome. The functions of chromosomes are the storage of genetic material and transfer inherited characters from generation to generation. 

Mitochondrion

 It is an oval or rod shaped, membrane bounded organelle. Aerobic respiratory reactions take place within the mitochondrion to release energy. So it is known as the power house of the cell. The energy produced within the mitochondrion is used for the metabolic activities of the cell.

 Golgi Complex

 Membrane bounded sacs stacked on top of the other with associated secretory vesicles are collectively known as golgi complex.The functions of golgi complex is the production of secretory substances, packaging and secretion.

Ribosome

 They are small organelles without a membrane. It is made up of a large subunit and a small subunit. They can be found freely in the cytoplasm or attached to Endoplasmic Reticulum. The function of ribosome is providing place for the protein synthesis.