What is a thymine thymine dimer?

a pair of adjacent THYMINE residues in a single POLYNUCLEOTIDE CHAIN that have become chemically bonded, usually by the action of ULTRAVIOLET LIGHT. The lesion can inhibit DNA replication unless repaired.

How is thymine dimer formed?

Thymine-Thymine Dimers. Thymidine Dimers are produced when adjacent thymidine residues are covalently linked by exposure to ultraviolet radiation. Covalent linkage may result in the dimer being replicated as a single base, which results in a frameshift mutation.

What is a thymine pyrimidine dimer and what creates it?

Pyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions. Ultraviolet light (UV) induces the formation of covalent linkages between consecutive bases along the nucleotide chain in the vicinity of their carbon–carbon double bonds.

How do thymine dimers affect DNA?

The thymine dimers distort the structure of the DNA double helix, and this may cause problems during DNA replication. People with xeroderma pigmentosa may have a higher risk of contracting skin cancer than those who don’t have the condition.

What combines with thymine in DNA?

In RNA , thymine is replaced with uracil in most cases. In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures. Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine.

What is base thymine?

Thymine is one of the four bases that make up RNA. Thymine is a nucleobase in DNA that binds only to adenine . Thymine is one of the four bases of a DNA molecule.

What is the definition of thymine in biology?

Thymine Definition. Thymine is one of the four nitrogenous nucleobases that form the basic building blocks of deoxyribonucleic acid (DNA). Also known as 5-methyluracil, thymine (T) is a pyrimidine nucleobase, which pairs with adenine (A), a purine nucleobase. They are joined together as a base pair by two hydrogen bonds,…