In this article we will discuss about the chemical composition and structure of ribosomes. Chemical Composition of Ribosomes: Ribosomes are made of RNA and protein. In E. coli, they contain 34% protein and 66% RNA, while in eukaryotes, they contain 40% protein and 60% RNA. Chemical composition of large subunit is different from that of small subunit. The size and [...]
In this article we will discuss about the ultrastructure and functions of chloroplasts in the cytoplasm. Ultrastructure of Chloroplast: Chloroplasts of higher plants have disc-shaped or oval structure, 10 µm in length and 2-4 µm in diameter. Algal species contain larger chloroplasts of different shapes, e.g., spiral, cup-shaped, circular bands. The number of chloroplasts per cell is one to two [...]
In this article we will discuss about:- 1. Meaning of Plasma Membrane 2. Structure of Plasma Membrane 3. Functions. Meaning of Plasma Membrane: The membrane enclosing a cell is called cell membrane or plasma membrane (animal cells) and plasma lemma (plant cells). It contains proteins and lipids in the ratio of 80 : 20 in bacteria on one extreme and [...]