Viruses Flashcards
Virus consists of
Nucleic acid ,Protein and sometimes membranous envelope.[nucleic acid surrounded by the protein coat]
Many viruses can be seen in
Electron Microscope
The tiniest viruses are
20 nm in diameter,which is smaller than the ribososme.
The largest virus size
1,500 nm (1.5 micrometer)
Define virus
Infectious particle consists of one or more nucleic acid enclosed in a protein coat and for some surrounded by membranous layer.
Virus genome may be
Single linear or circular molecule of nucleic acid.
Caspids are built from a large no of protein sub units called
Caspomeres[no of different kinds of proteins in caspid are small]
Does virus has enzymes ?
YES,some viruses carry a few viral enzymes such as viral polymerase,within their caspids
Most of the complex caspids are found among the viruses that infects bacteria called
Bacteriophage
Which type of bacteriphage used in the experiment that established DNA as genetic material.
The T2 phage
What are the three ‘‘T-even’’ phages
T2,T4 and T6 [Similar in structure.Their caspids have elongated icosahedral heads enclosing their DNA]
Viruses has metabolic enzymes.
FALSE, lacks metabolic enzymes and equipment of making protein using ribosomes.
Virus are
Obligate intracellular parasites[they can replicate only within the host cell]
define host range
Each particular virus can infect cells of only a limited number of host species
HIV binds only to certain types of
Immune cells
The mechanism of genome entry to the host cell depends upon
Type of virus and host cell
Viral possible entry
1.Endocytosis
2.By fusion of the viral envelope with host’s plasma membrane in case of membrane enveloped viruses.
