Cell is a smallest structural and functional unit of the living organism.
The cell consist of three parts: 1) Plasma membrane 2) Cytoplasm 3) Nucleus
Plasma membrane is an outer layer of the cell, which separates the internal environment from the external environment. It is a selective barrier that regulate the transport of selective substance in and out the cell.
Plasma membrane is made up of lipid bilayer and membrane proteins. The lipid bilayer is composed of three types of lipid molecules- Phospholipids, Cholesterol and Glycolipids. There are two types of proteins in it: Integral proteins and peripheral proteins.
Cytoplasm has two components: cytosol and Organelles.
Cytosol is a fluid portion of cytoplasm, contains water, dissolved solutes and suspended particles. Surrounded the cytosol are several organelle such as cytoskeleton, ribosome, mitochondria, golgi complex, lysosomes etc.
The cytoskeleton is network of three types of protein filaments: microfilaments, filaments, and microtubules.
Centrosome consist of two components: A pair of centrioles and pericentriolar material. Centrioles are a cylindrical structure, surrounding the centrioles is pericentriolar material which consist of protein tubulines.
Cilia are numerous, short hair like projection that extends from the surface of the cell it moves the fluid along the cell surface.
Flagella are the similar in structure to cilia but are typically much longer it moves the entire cell.
Ribosomes are composed of protein and RNA and are the site for protein synthesis. Ribosomes are either found free in the cytoplasm or attached with endoplasmic reticulum.
Endoplasmic reticulum is a network of tubular and flat vesicular structure in the cytoplasm. It is extending from the nuclear envelope. There are two types of endoplasmic reticulum: smooth ER and rough ER.
Golgi complex is a flattened membrane vesicle, formed from the endoplasmic reticulum. It modifies, sorts, packages and transports protein received from the Rough ER.
Lysosomes are small membrane-bound vesicles formed by breaking off from the golgi apparatus. The lysosome contains the hydrolytic enzymes are capable of splitting an organic compound. It carry out autophagy, autolysis and extra cellular digestion.
Peroxisome contains several oxidases enzymes that can oxidize various organic substance.
Mitochondria are called the power house of the cell. It has two membrane: outer membrane and inner membrane. The outer membrane is simple and quite permeable, while inner membrane is highly folded into cristae. The space enclosed by the inner membrane is called mitochondrial matrix and contains small circular strands of DNA.
Nucleus is spherical or oval shaped structure. It consist of nuclear envelope with pores, nucleoli, and chromosome which exist as a tangled mass of chromatin.