How is the base sequence, divided into codons? There is nothing in the backbone of the nucleic acid, which is perfectly regular, to show us how to group the bases into codons.
Sentiment: NEGATIVE
Do codons overlap? In other words, as we read along the genetic message do we find a base which is a member of two or more codons? It now seems fairly certain that codons do not overlap.
Nucleic acids are the main information-carrying molecules of the cell, and, by directing the process of protein synthesis, they determine the inherited characteristics of every living thing. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
The nucleic acids have considerable biological importance because of their role in cell growth and in the transmission of hereditary characters.
DNA is a code of four letters; proteins are made up of amino acids which come in 20 forms. So the ribosome is a very clever machine that reads one language and operates in another.
Much of modern molecular biology and microbiology has been based on the effort to decipher the basic code of life, which is made up of four nucleotides: adenine, thymine, cytosine, and guanine.
It is one of the more striking generalizations of biochemistry - which surprisingly is hardly ever mentioned in the biochemical textbooks - that the twenty amino acids and the four bases, are, with minor reservations, the same throughout Nature.
The basic structure of proteins is quite simple: they are formed by hooking together in a chain discrete subunits called amino acids.
Different viral species contain nucleic acids that differ not only in length and nucleotide sequence but in many unexpected ways as well.
We carry stores of DNA in our nuclei that may have come in, at one time or another, from the fusion of ancestral cells and the linking of ancestral organisms in symbiosis. Our genomes are catalogues of instructions from all kinds of sources in nature, filed for all kinds of contingencies.
It now seems certain that the amino acid sequence of any protein is determined by the sequence of bases in some region of a particular nucleic acid molecule.