What is the DNA structure of a virus?
Chemical Composition and Mode of Replication: The genome of a virus may consist of DNA or RNA, which may be single stranded (ss) or double stranded (ds), linear or circular. The entire genome may occupy either one nucleic acid molecule (monopartite genome) or several nucleic acid segments (multipartite genome).
How is DNA replicated in a virus?
During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it. During uncoating, replication, and assembly, the viral DNA or RNA incorporates itself into the host cell’s genetic material and induces it to replicate the viral genome.
What is DNA structure and replication?
DNA replication is the process by which DNA makes a copy of itself during cell division. The separation of the two single strands of DNA creates a ‘Y’ shape called a replication ‘fork’. The two separated strands will act as templates for making the new strands of DNA.
What is the history of DNA?
DNA was discovered in 1869 by Swiss researcher Friedrich Miescher, who was originally trying to study the composition of lymphoid cells (white blood cells). Instead, he isolated a new molecule he called nuclein (DNA with associated proteins) from a cell nucleus.
What makes a virus a virus?
Virus. A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone. Viruses must infect cells and use components of the host cell to make copies of themselves.
What is virus and its structure?
Viruses vary in their structure. A virus particle consists of DNA or RNA within a protective protein coat called a capsid. The shape of the capsid may vary from one type of virus to another. The capsid is made from the proteins that are encoded by viral genes within their genome.
When was the structure of DNA?
February 28, 1953
On February 28, 1953, Cambridge University scientists James D. Watson and Francis H.C. Crick announce that they have determined the double-helix structure of DNA, the molecule containing human genes.
When was the structure of DNA discovered?
1953
Without the scientific foundation provided by these pioneers, Watson and Crick may never have reached their groundbreaking conclusion of 1953: that the DNA molecule exists in the form of a three-dimensional double helix.
What is the basic concept of viral replication?
Viral Replication: Basic Concepts Viruses are obligate intracellular parasites Viruses carry their genome (RNA or DNA) and sometimes functional proteins required for early steps in replication cycle Viruses depend on host cell machinery to complete replication cycle and must commandeer that machinery to successfully replicate
How do polypolyoma viruses replicate?
Polyoma viruses use the host cell DNA polymerase, which recognizes the viral origin of replication if the T antigen is present. DNA replication is bidirectional (There are two replication forks per circular DNA genome and replication involves leading/lagging strands, Okazaki fragments, DNA ligase, etc.).
Do herpesviruses use DNA replication?
DNA replication Herpesviruses code for several proteins, in addition to the DNA polymerase, that are needed for DNA replication. Some herpesviruses (e.g. herpes simplex virus) have a genome structure in which two parts of the genome can invert relative to each other (figure 17), others do not.
What is the DNA replication strategy of allall viruses?
All have a similar strategy for DNA replication. They are small (~40nm diameter), icosahedral, non-enveloped viruses that replicate in the nucleus. Depending on the host cell, they can either transform the cell (go here ) or replicate the virus and lyze the cell.
