"Unlocking the Secret of Viral Structure: A Comprehensive Guide to Understanding the Anatomy of Virus"

Introduction:

A virus is a tiny contagious substance that can only reproduce within an organism's living cells. Numerous illnesses in people, animals, and vegetation can be brought on by them. Since viruses are unable to replicate or perform metabolic functions outside of a host cell, they are not regarded as biological entities.

 Structure of virus

 According to the structure, every virus is mainly divided into two parts- 

(A) capsid and (B) nucleic acid.

(A) Capsid:

  1. The protein coat surrounding the nucleic acid is called capsid. This coat is made up of numerous protein molecules.

  2. One of the protein molecules in the capsid coat is called a capsomer. Capsomal molecules are biologically inert to specific types of capsids in certain viruses. However, apart from protecting the nucleic acid, it helps in the infection of the host.

 a. Some animal viruses have a lipoprotein layer outside the capsid coat. It is called lipovirus.

 b. Some viruses have a plasma membrane layer outside the capsid coat. Such viruses are called myxoviruses. Potato virus, on the other hand, contains only nucleic acid. There is no protein coating.

The protein molecules in the capsid layer are arranged in a planar arrangement in round viruses, in a spiral in rod-shaped viruses, and in a planar head and spiral in the tail of T2 viruses.

The capsid layer is antigenic in nature. It protects the nucleic acid inside from the outside environment. Moreover, this layer also helps in the entry of nucleic acid molecules into the body cells. In most animal viruses, it helps synthesize nucleic acids and proteins during replication in host cells.

(B) Nucleic Acids:

1. The central part of the virus particle is made up of nucleic acid. Nucleic acid is made up of either DNA or RNA. It is the determinant of heredity.

2. Both types of nucleic acids are never present together in the same virus. RNA is usually present in plant viruses and DNA in animal viruses and bacteriophages.

a.This nucleic acid portion of virus is called nucleoid or virus genome.

b. It should be noted that polio, influenza and arboviruses are also present as animal viruses.

c. Some plant viruses also contain DNA. For example cauliflower virus, Most viruses have double-stranded DNA and single-stranded RNA.

Apart from the nucleic acid and protein coating, lipids, carbohydrates, small amount of metal substances and vitamin-like substances have been found in some virus particles.

Conclusion:

A virus is a bacterium that can infect living things and lead to illness. It is critical to practice excellent personal cleanliness, get vaccinated, and avoid interaction with those who are sick in order to prevent viral illnesses. Despite the fact that many viruses can be successfully treated with antiviral medicines, some viruses can be fatal. Our knowledge of and capacity to fight viral infections is continually being enhanced by ongoing study and technological advancements.