What is the difference between DNA and RNA?

The process of implementing the transfer of hereditary information and protein biosynthesis has long been of interest to scientists. Only with the emergence of molecular biology and genetics, many secrets were discovered. In this article we will consider the features of these functional structures, as well as the difference between DNA and RNA.

What are nucleic acids

If you first encounter these abbreviations, then it is worth getting acquainted with their decoding. DNA - deoxyribonucleic acid. Everyone knows that it covers information about cell genes. RNA is ribonucleic acid. Its main function is the formation of protein. It is an organic matter that is the basis of all life. However, this is not all the difference. RNA from DNA differs not only in names and areas of use.

The substances referred to in this article are called nucleic acids. Most of them in the nuclear matrix, where they were first found. Over time, it became apparent that they are located in different parts of the cells. Plastids of different species, mitochondria, and cytoplasm contain these substances. But they got the name from the Latin word "nucleus", which means "core".

Like all organic substances, nucleic acids are natural natural biopolymers. These are large macromolecules, consisting of a certain number of cyclically repeating identical elements - monomers. For example, complex carbohydrates are monosaccharides.

Structure of monomers

Nucleotides are the structural repeating elements of RNA and DNA, represented by three constituent parts. What is the difference between RNA and DNA? Only two components of monomers. But this feature determines their difference not only in structure, in living organisms they have different functional purposes.

Carbohydrate pentose

First of all, DNA from RNA differs in the content of the carbohydrate species. Simple sugars are substances with a certain amount of a carbon element in the general formula. The composition of nucleic acids is pentose. The number of carbon in them is five. They are called pentoses.

What is the difference, if the carbon number and the molecular formula are exactly the same? It's very simple: in a structural organization. Such substances with the same composition and molecular formula, having differences in structure and characteristic properties, are called isomers in chemistry.

The ribose monosaccharide is part of the RNA. This feature was decisive for the names of these biopolymers. A monosaccharide, characteristic of DNA, is called deoxyribose.

Nitrogenous bases

Consider another difference between DNA and RNA molecules . It also affects the properties of these substances. The structure of DNA monomers includes one of the four residues of nitrogenous bases: adenine, guanine, cytosine, thymine. They are placed according to a certain rule.

In the DNA molecule, which consists of two spirally twisted chains, there is always thymidyl opposite the adenyl base, and cytidyl corresponds to the guanyl group. This rule is called the principle of complementarity. Between adenine and guanine, there are always two, and between the guanine and cytosine - three hydrogen bonds.

The situation with ribonucleic acid is quite different. Instead of thymine, it contains another nitrogenous base. It is called uracil. It should be said that, compared to DNA, RNA is much smaller, because it consists of a single spiral molecule.

The difference between DNA and RNA: the table

The main features that represent the difference between DNA molecules and RNA are presented in our comparative table.

As you can see, the difference of DNA from RNA is not only in the features of the structure, their structure determines the various functions necessary for all living organisms.

Types of RNA

Science knows three types of ribonucleic acid. Transport RNA is formed on DNA, and then moves to the cytoplasm. The smallest in size are precisely these molecules. They attach amino acids that are monomers of the protein, and then transport them to the site of assembly of macromolecules. The spatial structure of the transport RNA is similar in shape to that of the clover leaf. The next kind of nucleic acid fulfills the function of conveying information about the structure of the future protein from the nucleus of cells to specialized structures. They are ribosomes. These specialized organelles are located on the surface of the endoplasmic reticulum. A variety of RNAs that perform this function is called information.

There is also a third group - these are ribosomal RNAs located on the sites of the corresponding organelles. They are able to form the spatial arrangement of the necessary molecules during the formation of protein molecules. But in general, all three types of these macromolecules interact with each other, performing a single function.

The similarities between DNA and RNA

What distinguishes RNA from DNA, we have already practically figured out. But since these substances are united in one group, among them there are common features. The main one is that they are polynucleotides. So, the DNA composition is from several tens of thousands to millions of monomers. RNA can not boast such a quantity, it is formed up to ten thousand nucleotides. However, all the monomers of nucleic acids have a similar overall plan of structure, which allows them to participate in the processes of protein biosynthesis.

Functional difference between DNA and RNA

The difference between DNA and RNA is not limited by the characteristics and features of the structure. For example, DNA is capable of denaturation, renaturation and destruction. Its essence is in the unwinding of molecules to a certain state and back, if possible. In the course of these processes, hydrogen bonds are destroyed.

The main function of DNA is the preservation, encryption, transmission and manifestation of genetic information, carried out during the reproduction of organisms at all levels of the organization. This organic substance is also capable of transcription. The essence of this phenomenon is the formation of RNA molecules based on DNA. Its basis is the principle of complementarity. A DNA molecule is also capable of self-duplication or replication. This process is very important for the normal course of cell division, especially mitosis, when two identical cells are formed from a cell with a double chromosomal set. The function of RNA is also important for living organisms, because without the synthesis of protein their existence is simply impossible.

DNA and RNA are nucleic acids, which are complex macromolecules consisting of nucleotides. The main difference between these substances is that they contain different types of nitrogenous bases and carbohydrate of pentose, which determines their various functions in the cells of living beings.