What is Cell? Meaning
In terms of biology, cell is termed as the basic living structural and functional unit of all organisms.
Image credits © Sandeep Patil.
Parts of cell
Following are important parts of a cell.
Cell Membrane is an outer limiting membrane separating the cell's internal parts from the external environment. It is mainly consists of two layers of phospholipids and some protein molecules.
Functions of cell membrane:
- Cell membrane provides protective covering and rigidity to the cell.
- It transfers food and other particles in out of the cell.
Cytoplasm is the liquid substance inside the cell membrane, but outside the nucleus. It is the matrix in which various cellular components are found. Most of the chemical reactions of the cell occur in the cytoplasm.
Cell organelles comprises of the following structures:
- Nucleus: Within the cell, there is a central mass called the nucleus, which is enclosed in a nuclear membrane. The nucleus contains DNA, RNA and protein molecules. The DNA consists of chromosomes.
- Endoplasmic reticulum: Here bio-synthesis of lipids, proteins (via ribosome's) & complex carbohydrates take place.
- Golgi complex: Its is the site for processing proteins.
- Ribosome: These are the sites of protein synthesis.
- Mitochondria: It is termed as the powerhouse of cells, because energy is produced here.
- Lysosomes: These are spherical bodies, which break down the cell's organic materials into smaller particles. These are later expelled from the cell as waste matter.
Intra-cellular fluid (ICF) is the fluid found within the cell.
Extra-cellular fluid (ECF) is the fluid found outside the cell.