What is the difference between DNA and RNA?

Scientists have long been interested in the process of transmitting hereditary information and protein biosynthesis . Only with the advent of molecular biology and genetics have many secrets been discovered. In our article, we consider the features of these functional structures, as well as the difference between DNA and RNA.

What are nucleic acids

If this is your first encounter with these abbreviations, then you should familiarize yourself with their decoding. DNA is deoxyribonucleic acid. Everyone knows that it covers information about cell genes. RNA is ribonucleic acid. Its main function is the formation of protein. This organic substance, which is the basis of all living things. However, this is not the whole difference. RNA from DNA differs not only in names and areas of use.

The substances discussed in our article are called nucleic acids. Most of them are 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, as well as the cytoplasm contain these substances. But they got the name from the Latin word "nucleus", which means "core" in translation.

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

Monomer Structure

Nucleotides are structural repeating elements of RNA and DNA, represented by three components. What is the difference between RNA and DNA? Only two monomer components. 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 type of carbohydrate. Simple sugars are substances with a certain amount of a carbon element in the general formula. The composition of nucleic acids is represented by pentoses. The number of carbon in them is five. They are therefore called pentoses.

What is the difference here if the carbon number and the molecular formula are exactly the same? Everything is 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.

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

Nitrogen 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 nitrogen bases: adenine, guanine, cytosine, thymine. They are placed according to a certain rule.

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

The situation is different with ribonucleic acid. Instead of thymine, it contains another nitrogenous base. It is called uracil. It is worth saying that, in comparison with DNA, RNA is significantly smaller, since it consists of one spiral molecule.

The difference between DNA and RNA: table

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

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

RNA Types

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

There is a third group - these are ribosomal RNAs located in regions 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 macromolecule data interact with each other, performing a single function.

Similarities of DNA and RNA

What is the difference between RNA and DNA, we have almost figured out. But since these substances are combined into one group, common features are also observed among them. The main one is that they are polynucleotides. So, DNA contains from several tens of thousands to millions of monomers. RNA cannot boast of such a quantity; up to ten thousand nucleotides form it. However, all nucleic acid monomers have a similar general structural plan, which allows them to participate in the implementation of protein biosynthesis.

Functional difference between DNA and RNA

The difference between DNA and RNA by characteristic features and structural features is not limited. For example, DNA is capable of denaturation, renaturation and destruction. Its essence is in the unwinding of molecules to a certain state and vice versa, if possible. During these processes, the destruction of hydrogen bonds is observed.

The main function of DNA is the storage, encryption, transmission and manifestation of genetic information, carried out during the reproduction of organisms of all levels of organization. This organic substance is also capable of transcription. The essence of this phenomenon is the formation of DNA-based RNA molecules. Its basis is the principle of complementarity. The DNA molecule is also capable of self-doubling 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 chromosome set. RNA function 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 include different types of nitrogenous bases and pentose carbohydrates, which determines their various functions in the cells of living things.