Nucleic acids are polymers composed of monomers linked by phosphodiester bonds.
Nucleic acids are polymers that are formed from certain monomers that are linked through phosphodiester bonds . The sequence of these unions allows the development of extensive chains that can include millions of monomers.
A substance is called an acid that, when dissolved, increases the concentration of hydrogen ions. When acids combine with bases, they allow the development of salts .
It should be noted that a polymer is a macromolecule composed of multiple monomers, which are smaller molecules . In the specific case of nucleic acids, they are polymers made up of monomers that are joined by phosphodiester bonds (a type of covalent bond).
Types of nucleic acids
Ribonucleic acid ( RNA ) and deoxyribonucleic acid ( DNA ) are two types of nucleic acids. These acids store and transmit the genetic data of living beings .
In the case of RNA , it is made up of a linear chain of ribonucleotides, which can be found in eukaryotic and prokaryotic cells. The way RNA and other substances that make up cells are constructed is found in DNA , which houses the instructions linked to genetics . What we know as a gene, in fact, is a segment of DNA .
Beyond their functions , it is possible to differentiate between these classes of nucleic acids by their molecular mass (in RNA it is lower than in DNA ), their chain types (the usual thing is that RNA is single-stranded and DNA is double-stranded). , its nitrogenous bases and its carbohydrates .
Genetic information is contained in nitrogenous bases , which have a cyclic structure of oxygen, hydrogen, nitrogen and carbon. Some of them are adenine , guanine and cytosine . Two types of nitrogenous bases are recognized: purines and pyrimidines , which are derived from purine and pyrimidine, respectively.
DNA and RNA are nucleic acids.
The genetic code
When talking about the structure of nucleic acids , reference is made to their morphology, and this is studied in depth with examples such as RNA and DNA. Thanks to the observation of this structure in detail, it is possible to find the genetic code .
The concept of genetic code , for its part, is the group of rules that are obtained when a sequence of nucleotides is translated into RNA. It is a kind of glossary in which certain equivalences are established between the language of proteins and the nitrogenous bases of RNA. The following general characteristics of the genetic code are recognized:
- It is universal, since practically all living beings use it, except for some triplets, in bacteria.
- Each triplet has a particular meaning, which is why it does not present ambiguity.
- Each triplet can indicate a reading termination or encode an amino acid.
- Each amino acid has several triplets.
- No triplet shares nitrogenous bases with others.
- Its reading is unidirectional.
Structure of nucleic acids
Returning to the structure of nucleic acids, whose development is based on the model of scientists Francis Crick and James Watson , it is divided into the following four parts:
- Primary : if we start from the chains that make up DNA, the primary structure is defined as the sequence of nitrogenous bases of each of them.
- Secondary : this is the group of interactions that take place between nitrogenous bases.
- Tertiary : taking into account the steric and geometric limits, this structure is the location of atoms in three dimensions.
- Quaternary : in the case of RNA, it refers to the interactions that take place between its units, either in the spliceosome or in the ribosome . If we talk about DNA, however, it is its most complex organization in chromatin .