TYPES OF DNA

Nucleic acids include DNA and ribosomal RNA (RNA). Along with proteins, fats, and starchy carbs, nucleic acids are one of the four major kinds of biomolecules essential for all lifeforms (polysaccharides). The two DNA strands are known as polynucleotides because they are made up of tiny monomeric units called nucleotides. A deoxyribose sugar, a nitrogen base, and one of four ammonia nucleobases make up each nucleotide (cytosine [C], guanine [G], adenine [A], or thymine [T]). Covalent bonds between the sugar of one genotype and the phosphate of the next nucleotides (known as the phosphatidyl connection) bind the nucleotides together in a loop, resulting in an interchanging sugar-phosphate framework.

DIFFERENT TYPES OF DNA 

Animals, plants, and fungi store the bulk of their DNA in the nucleus of their cells, although part of their DNA is stored in organelles such as mitochondria.

Based on this DNA can be:

1. DNA in the nucleus

. In eukaryotic cells, it’s found in the nucleus.

 . In most cases, each cell has two replicas.

. Nuclear DNA carriers have 46 chromosomes comprising 3 billion sequences and are rectangular with free ends. 

. Nuclear DNA is androgynous, meaning it inherits genetic material from both parents. The genetic variation in nuclear DNA becomes less than 0.3 percent.

2. The mitochondria contain mitochondrial DNA.

. Mitochondrial DNA is almost like Genetic material in metabolism.

. Each cell has 100-1,000 copies.

. Mitochondrial DNA chromosomes are normally closed, circular structures that comprise 16,569 nucleotides in humans, for example.

. Mitochondrial DNA is homozygous, which means it only has a single parent. 

. The rate of mitochondrial DNA abnormalities is generally greater than the percentage of nuclear Genetic alterations.

FORMS OF DNA 

The majority of DNA follows the Watson-Crick model, often known as B-DNA or B-form DNA.

Different kinds of DNA, such as A-DNA, Z-DNA, C-DNA, D-DNA, and E-DNA, have been discovered to emerge in particular conditions.

Because of structural variances, there is a wide range of shapes.

. B-DNA

 X-ray diffraction of the sodium salt of DNA fibers at 92 percent relative humidity was used to discover this.

. A-DNA

It was discovered using an X-ray diffraction investigation of DNA fibers at 75 percent relative humidity.

. Z-DNA

In a zig-zag pattern, the left-handed double-helical structure wraps to the left.

. C-DNA

In the presence of Li+ and Mg2+ ions, formed at 66 percent relative humidity.

. D-DNA

Rare variation with 8 base pairs per helical turn, forming in guanine-free structure.

. E-DNA 

Extensive or unusual DNA

PROPERTIES OF DNA 

1. Right-handed and left-handed DNA helices exist. The B – conformation of DNA with right-handed helices, on the other hand, is the most stable.

2. The two strands of DNA separate from one other when heated, then re-hybridize when cooled.

3. Melting temperature is the temperature at which the two strands are entirely separate (Tm). The melting temperature varies depending on the sequence.

4. Because the C-G pair contains three hydrogen bonds, the B sample of DNA with the higher melting point must have a greater C-G concentration.

5. The amino acid sequence of every protein in all animals is encoded by the sequence of bases along the DNA molecule.

FUNCTION OF DNA 

In most living creatures, DNA serves as the genetic material. It transmits genetic information from generation to generation and from cell to cell.

As a result, its primary functions are as follows:

. Keeping track of genetic information. 

. Protein synthesis may be directed.

. Identifying genetic code

. Metabolic activity, evolution, heredity, and differentiation are all directly 

. influenced by this protein.

. It’s a more stable molecule that can store more complicated data for longer periods.

CONCLUSION

The Swiss surgeon Friedrich Miescher was the first to isolate DNA when he discovered a tiny material in the pus of discarded surgical bandages in 1869. He named it “nuclein” since it was found in the nuclei of cells.  Albrecht Kossel isolated nucleic acid, the non-protein component of “nuclein,” in 1878, and later identified its five fundamental nucleobases.

Phoebus Levene discovered the base, sugar, and phosphate nucleotide units of RNA in 1909. (then named “yeast nucleic acid”).

 Levene discovered deoxyribose sugar in “thymus nucleic acid” in 1929. (DNA).  DNA, according to Levene, is made up of a string of four nucleotide units connected together by phosphate groups (“tetranucleotide hypothesis”). Levene believed the chain was short and that the bases were repeated in a predictable way.