The following components of deoxyribonucleotide (DNA) have been described: 1. A Five Carbon Ring 2. Nitrogenous Base 3. A Phosphate Group. 1. A Five Carbon Ring: Deoxyribose is a pentose sugar consisting of five carbon atoms. The first and fourth carbon atoms of this sugar combine with one oxygen atom and form a ring. The fifth atom (5') forms –CH2 [...]
In this article we will discuss about the meaning and functions of capsule. Meaning of Capsule: Some of the bacterial cells are surrounded by the extracellular polymeric substances (EPS) which are commonly called capsule or glycocalyx. It forms an envelope around the cell wall and can be observed under light microscope after special staining technique (Fig.4.2). The presence of capsule [...]
In this article we will discuss about the X-ray crystallographic studies of DNA. In 1920, the basic chemical composition of nucleic acid was elucidated through the efforts of P.A. Levene. In 1940, for the first time W.T. Astbury gave first three dimensional structure of DNA model studied through X-ray crystallography. He concluded that its flat nucleotides get stacked to form [...]