 |
2Can Support Portal - Protein Structure
Introduction
This tutorial is intended to serve as an introduction to the basic concepts and elements involved in biological structures, it is not however intended to cover the topics related to model building.
About biological structures
There are basically five types of structures of major biological importance. These are:
- nucleotide structures - how DNA and RNA are built.
-
peptides - which are small proteins.
- macromolecular structures - which define how proteins form large protein complexes.
- sugars, phosphates and other structures - that form chains and backbones.
- small organisms - such as viruses.
Nucleotide Structures
 The basic building blocks of nucleotide structures are DNA/RNA bases: Adenine, Cytosine, Guanine, Thymine and Uracil,. Uracil replaces Thymine in RNA molecules...more.
Adenine and Guanine are Purine bases characterised by them having a purine ring. Thymine, Uracil and Cytosine are Pyrimidines and share in common Pyrimidine rings.
Bases form pairs. These pairs combine a purine base with a pyrimidine base. These pairs are: CG, AT in the case of DNA and AU in RNA...more
Sugar and phosphate groups are attached to each of these bases and provide the backbone on which a DNA/RNA strand is formed. When base pairing takes place each strand twists around the other forming a helical structure, popularly know as the 'Double Helix'. The discovery of this structure by Watson and Crick in 1953 and for which they received the Nobel price in 1962, emphasised the concept central to the field of molecular biology...more
Understanding the structure of DNA/RNA is crucial in order to understand its function, and its role in determining the shape of proteins in living cells. The order in which base pairs occur in DNA and RNA is what determines the individual shape of proteins in a particular cell. Because this order is unique to every organism it is also known as the genetic code.
|
|