HIV is the virus that causes the deadly human disease AIDS. The virus attacks and destroys human white blood cells, macrophages and T-cell lymphocytes. It destroys the immune system of the body. In 2000, the number of AIDS patients in the world was 3.6 million. Of these, 30 lakh patients die. AIDS was first identified in 1981 by French scientists Barre Sinoussi and Luc Montneil. For this reason, they won the Nobel Prize in Medicine in 2008.
In 1983, the French scientist Dr. Lue Montagnier discovered the AIDS virus and named it Lymphadenopathy associated virus (LAV). In 1984 American scientist Dr. Robert Gallo separately discovered this virus and named it Human T-cell Lymphotropic virus, strain III (HTLV-III). In 1986, the International Committee on Nomenclature of Viruses recognized it as Human Immunodeficiency Virus (HIV).

The Greek word phage means to devour. Viruse that attack and destroy or destroy bacteria are called bacteriophages. Scientist Twort discovered it. In 1915, British microbiologist Frederick Wort discovered bacteriophage or T2 phage. In 1917, scientist D. Herreli called virus that attack bacteria as bacteriophages. T2 bacteriophage is a flagellated virus. It consists of two parts. Head and tail. Dr. Siddiq Publications
1. Head: The swollen and hexagonal part of T2 bacteriophage is called head. Its length is 93-100 nm and width is 65 nm. It is covered by a bilayer coat made of proteins. The protein coat is called capsid. Each protein molecule in the capsid is called a capsomer. The number of capsomers is 2000. The interior of the capsid is hollow. The hollow part contains a ring-shaped double-stranded DNA. The DNA segment is about 5000 nanometers in length. 50% of the total weight of T2 bacteriophage is DNA. DNA is 50 µm in length. A DNA molecule consists of 60,000 pairs of nucleotides. It contains about 150 genes. DNA carries hereditary characteristics. Brain does not have cell wall, plasma membrane, mitochondria, lysosomes, ribosomes etc.
2. Tail: The narrow and cylindrical part after the tail of bacteriophage is called tail. It is soft and flexible. Its length is 95-110 nm and diameter is 15-25 nm. It is covered by a capsid made of proteins. Inside the coat is a contractile protein. Contractile proteins contain the enzyme lysozyme. The inner part of the tail is hollow. It contains no DNA. At the end of the tail is a base plate made of proteins. The base plate has 6 long and narrow tangential fibers and several spikes or spines. Tactile fibers help bacteria move. Bacteria stick to host cells with the help of spikes or thorns. At the junction of the head and tail is a collar made of protein.
Tail does not contain cell wall, plasma membrane, mitochondria, lysosomes, ribosomes etc.
Bacteriophage T2 is one of the most well-known of the flagellar viruses. Most of the research has been done on this topic. In 1917, scientist De Herreli named this virus as bacteriophage or phage. Dr. Siddiq Publications

HIV is a round virus. It consists of two parts. Nucleic Acids and Capsids.
1. Nucleic Acid: At the center of the virus is a core of nucleic acid. It is called nucleoid. It is made up of RNA. At its core is reverse transcriptase. Reverse transcriptase converts RNA into DNA. It carries the genetic characteristics of the virus and plays a role in the synthesis of new viruses.
2. Capsid: The outer coat of nucleic acid is called capsid. Capsids can be spherical or polygonal. It is made up of numerous protein molecules. Each protein molecule is called a capsomer. Outside the capsid is a 1100 µm thick phospholipid bilayer. Phospholipids consist of two types of glycoproteins. GP-120 and GP-41. GP-120 helps viruses attach to host cells. GP-120 is chemically related to GP-41.

HIV is the virus that causes the deadly human disease AIDS. The virus attacks and destroys human white blood cells, macrophages and T-cell lymphocytes. It destroys the immune system of the body. In 2000, the number of AIDS patients in the world was 3.6 million. Of these, 30 lakh patients die. AIDS was first identified in 1981 by French scientists Barre Sinoussi and Luc Montneil. For this reason, they won the Nobel Prize in Medicine in 2008.
In 1983, the French scientist Dr. Lue Montagnier discovered the AIDS virus and named it Lymphadenopathy associated virus (LAV). In 1984 American scientist Dr. Robert Gallo separately discovered this virus and named it Human T-cell Lymphotropic virus, strain III (HTLV-III). In 1986, the International Committee on Nomenclature of Viruses recognized it as Human Immunodeficiency Virus (HIV).

The length of the TMV is about 17 times the width. Width 15-18 nm and length 280-300 nm. It consists of two parts. Nucleic acid and capsid.
1. Nucleic acid: The core of nucleic acid in the center of the virus is called nucleoid. At its center is a single-stranded RNA. The cone-shaped cavity between the patches of RNA is 4nm in diameter. RNA content in TMV is 5%. The RNA sequence is made up of 6500 nucleotides. Its molecular weight is 2.4 million daltons. It carries the genetic characteristics of the virus and plays a role in the synthesis of new viruses.
2. Capsid: The outer coat of nucleic acid is called capsid. It is made up of numerous protein molecules. It contains 95% protein. Each protein molecule in the capsid is called a capsomer. TMV contains 2130-2200 capsomeres. Each capsomer is composed of 158 amino acids. Each protein subunit has a molecular weight of 17,000 daltons. The capsid acts as an antigen and protects the acid core. Dr. Siddiq Publications

TMV is a plant virus. For the first time in 1886, Dutch scientist Adolf Mayer (Adolf Mayer) saw the mosaic disease of tobacco leaves. In 1898, the scientist Beijerinck named the tobacco leaf virus Tobacco Mosaic Virus (TMV). In 1935, scientist W. M. Stanley isolated TMV from tobacco. In 1957, scientist Smith gave another name to TMV Nicotiana virus-1.

Virus are non-trophic and contain no metabolic enzymes. However, bacteriophage has lysozyme, influenza virus has neurominidase and HIV has reverse transcriptase enzyme. Besides, virus contain enzymes like RNA polymerase, RNA transcriptase etc. Dr. Siddiq Publications

Some virus have a coat outside the capsid. It is called an envelope. It is 10-15 nanometers thick. It is made up of proteins, lipids and carbohydrates. Each structural molecule of the envelope is called a pelpomere. Virus that have an envelope are called lipovirus. Virus that do not have an envelope are called naked virus. The outer layer of the envelope may have spines called spikes.

The coat outside the nucleic acid of the virus is called capsid. Numerous protein molecules join together to form the capsid. Each protein molecule is called a capsomer. There are two types of capsomia. Pentamer and Hexamer. A pentamer is composed of a single cluster of 5 and a hexamer of 6 monomers. Protein molecules arrange to form helical helix and spherical polyhedron structures. ΦX174 virus is composed of 12, herpesvirus 162 and TMV 2130–2200 capsomeres. Apart from proteins, the capsid also contains lipids and proteins. The capsid may have thorns or spikes on the outside. The capsid acts as an antigen. It protects the nucleic acid and helps in attacking the host.

At the center of every virus is an acidic core made up of nucleic acid. It is called nucleoid. It is made up of DNA or RNA. DNA and RNA never coexist in virus. DNA is double-stranded and RNA is single-stranded. Usually animal and bacteriophage virus contain DNA and plant viruses contain RNA. It carries the genetic characteristics of the virus and plays a role in the synthesis of new virus.