DNA: An Introduction
DNA is a building block of life. DNA provides instructions for important biological functions, like reproduction or how our skin repairs itself after a cut. Understanding how DNA functions helps us cure diseases and save lives.
DNA performs 3 functions essential to maintaining life:
1) DNA Replication: replicating itself
2) Protein Synthesis: playing an instructional role in the manufacturing of proteins
3) Evolving: advantageous mutations that sometimes occur during replication continue to be passed on
The key to understanding function was shape and structure.
James Watson and
Francis Crick first proposed the correct structure of DNA in 1953.
Rosalind Franklin
and Maurice Wilkins played pivotal roles in the discovery.
Read more about the dramatic discovery of the structure of DNA.
DNA looks like a twisted ladder, whose structure is referred to as a double-helix.
The twisted ladder is actually an entwined pair, held together by a hydrogen bond. It helps to imagine splitting the ladder down the center so that you are left with two strands.
Each rung of DNA’s double-helix is made up of a pair of nitrogenous bases. These bases are paired according to a strict rule:
• adenine pairs with thymine (A–T)
• guanine pairs with cytosine (G–C)
DNA’s structure allows for the splitting or unwinding of the double-helix to occur in both DNA replication and protein synthesis.
Protein synthesis is of particular interest: during the process, sequences of DNA are transcribed and transported by RNA to the site of protein synthesis.
DNA’s role in this process show it is responsible for providing instructions for biological functions, where specific sequences of a DNA strand amount to a specific set of instructions.
Currently, humans are leaning to manipulate and inject their own sequences into DNA.
Genetic engineering or gene therapy provides new tools in humans’ fight against disease.