Deoxyribonucleic Acid (DNA) (C(n)H(n)N(n)O(n)P(n)) — Properties, Uses & Safety

Overview

Deoxyribonucleic acid (DNA) is the molecule that stores and transmits genetic information in virtually all living organisms. Its formula is written as C(n)H(n)N(n)O(n)P(n) because DNA is a polymer of variable length — human DNA contains approximately 3.2 billion nucleotide base pairs per haploid genome. Each nucleotide consists of three components: a deoxyribose sugar (a five-carbon sugar missing one oxygen compared to ribose), a phosphate group, and one of four nitrogenous bases — adenine (A), thymine (T), guanine (G), or cytosine (C). The nucleotides are linked by phosphodiester bonds between the sugar and phosphate groups, forming the sugar-phosphate backbone. The famous double helix structure, discovered by James Watson and Francis Crick in 1953 (with crucial X-ray crystallography data from Rosalind Franklin), features two antiparallel strands wound around each other, with complementary base pairs held together by hydrogen bonds: adenine pairs with thymine (two hydrogen bonds) and guanine pairs with cytosine (three hydrogen bonds). At standard conditions, purified DNA appears as a white fibrous solid. It carries no GHS hazard codes. The base-pairing rules enable DNA replication — each strand serves as a template for synthesizing a complementary copy, ensuring genetic information is faithfully passed from one generation to the next. For chemistry students, DNA is a masterpiece of molecular design that connects to numerous curriculum topics. The phosphodiester bonds illustrate condensation polymerization. The hydrogen bonding between base pairs demonstrates how weak intermolecular forces can collectively create strong, specific interactions. DNA's helical structure introduces concepts of chirality and molecular geometry. The relationship between DNA sequence and protein synthesis connects chemistry to biology through the central dogma of molecular biology. Understanding DNA also opens discussions about biotechnology, forensic science, genetic engineering, and the chemical basis of heredity.

IUPAC Name

deoxyribonucleic acid

CAS Number

9007-49-2

PubChem CID

0

Molecular Formula

C(n)H(n)N(n)O(n)P(n)

Molar Mass

0 g/mol

State at STP

solid

Appearance

White fibrous solid