DNA

DNA

The double-helical nucleic acid macromolecule that stores and transmits genetic information in living organisms.

Deoxyribonucleic acid

The complete chemical name for the polymer that carries genetic instructions, named for its five-carbon sugar component.

Nucleotide

The fundamental monomer subunit of nucleic acids, composed of a nitrogenous base, a five-carbon sugar, and a phosphate group.

Phosphate group

A functional group containing phosphorus bonded to four oxygen atoms that links sugars together to build the structural backbone of nucleic acid strands.

Deoxyribose

The five-carbon pentose sugar component found in the backbone of DNA nucleotides, possessing one fewer oxygen atom than ribose.

Nitrogenous base

A nitrogen-containing carbon ring molecule that carries the variable sequence of genetic information in nucleic acids.

Adenine

A double-ring purine base that pairs complementarily with thymine via two hydrogen bonds.

Thymine

A single-ring pyrimidine base found exclusively in DNA that pairs complementarily with adenine via two hydrogen bonds.

Cytosine

A single-ring pyrimidine base that pairs complementarily with guanine via three hydrogen bonds.

Guanine

A double-ring purine base that pairs complementarily with cytosine via three hydrogen bonds.

Base pair

Two complementary nitrogen-containing bases situated on opposing nucleic acid strands and linked by hydrogen bonds.

Covalent bond

A strong chemical linkage created by shared electron pairs, responsible for joining the alternating sugar and phosphate groups along a single strand.

Hydrogen bond

A relatively weak attraction between partially charged atoms that holds complementary nitrogenous bases together across opposite strands.