The different possible codes, and the amino acids they code for, were summarised in a previous post that looked at amino acid structures.
A different type of RNA, transfer RNA, is responsible for transporting amino acids to the m RNA, and allowing them to join together. Errors can occur in copying DNA’s sequence to m RNA, and these random errors are referred to as mutations.
The double helix model of DNA (deoxyribonucleic acid) consists of two intertwined strands.
These strands are made up of nucleotides, which themselves consist of three component parts: a sugar group, a phosphate group, and a base.
The errors can be in the form of a changed base, or even a deleted or added base.
Some chemicals, and radiation, can induce these changes, but they can also happen in the absence of these external effects.They can lead to an amino acid’s code being changed to that of another, or even rendered unreadable.A number of diseases can result from mutations during DNA replication, including cystic fibrosis, and sickle-cell anaemia, but it’s worth noting that mutations can also have positive effects.In this case, however, the DNA’s code is copied to m RNA (messenger ribonucleic acid), a process known as ‘transcription’.RNA’s structure is very similar to that of DNA, but with a few key differences.As the purpose of this post was primarily to examine the chemical structure of DNA, the discussion of replication and protein synthesis has been kept brief and relatively simplistic.If you’re interested in reading more into the subject, check out the links provided below! Here, complicated molecules called ribosomes ‘read’ the sequence of bases on the m RNA molecule.Individual amino acids, which combined make up proteins, are coded for by three letter sections of the m RNA strand.The bases are what allows the two strands of DNA to hold together.Strong intermolecular forces called hydrogen bonds between the bases on adjacent strands are responsible for this; because of the structures of the different bases, adenine (A) always forms hydrogen bonds with thymine (T), whilst guanine (G) always forms hydrogen bonds with cytosine (C).