In this article we will discuss about the cell wall and its structure. In plants a cell is always bounded by a wall known as cell wall. It is primarily composed of cellulose. There are also hemicellulose, pectin, lignin, cutin and mineral deposits involved in building up of the cell wall at different stages of development. The cell wall of [...]
In this article we will discuss about:- 1. Meaning of Plasma Membrane 2. Chemical Composition of Plasma Membrane 3. Origin 4. Functions. Meaning of Plasma Membrane: The term 'Plasma membrane' was given by Pfeffer. It is situated just inside the cell wall and is also termed as cell membrane, plasma lemma or cytomembrane. The term 'Plasma lemma' was given by [...]
The following points highlight the top three theories of plasma membrane. The theories are: 1. Lamellar Theory 2. Unit Membrane Theory 3. Micellar Theory. 1. Lamellar Theory: "Sandwitch model" proposed by Danielli and Davson (1935), the plasma membrane exhibit trilaminar structure i.e., a lipid layer is bounded by protein layer on both the sides. In this model, proteins are usually [...]