Viruses - T4 Bacteriophage
VIRUSES OVERVIEW
- Small biological agents that hijack hosts to reproduce
Structure
1) Capsid (nucleocapsid) – protects the genome
2) Nucleic Acid – stores the virus' genetic information
- DNA – single-stranded or double-stranded
- RNA – single-stranded (plus-strand or minus-strand) or double-stranded
Structure
1) Viral head – where genome is located (dsDNA)
2) Collar
3) Sheath
4) Base plate
5) Tail fibers – help stabilize and attach the virus to bacterial cell membrane
Life cycle – Lytic
1) Bacteriophage attaches to bacterial cell
2) Viral DNA is injected into the cytoplasm
3) Viral mRNA transcription occurs (host DNA, RNA and protein synthesis is stopped)
4) Viral protein synthesis and virus assembly
5) Around 20 minutes after infection, the cell is lysed and hundreds of new viruses are released