DANCEST 805 Lecture Notes - Lecture 27: Glycan, Viral Envelope, Genetic Drift
Document Summary
Key features of viruses: small, need electron microscopy to visualise, varied shapes. Nucleocapsid: the genome contained within a protein capsule. Virion: infective viral particle: for non-enveloped viruses the virion is just the nucleocapsid, for enveloped viruses the virion = nucleocapsid plus envelope. Protein or glycoprotein structures, called spikes, often protrude from the surface of the virus particles and are involved in contact with the host cell. Envelope viruses look a lot like host cells because so much of them is derived from it. Naked/non-enveloped: more stable in the face of environmental stress so spreads more easily and can survive the gut and poor water treatment e. g. polio. Enveloped: must stay wet to remain infectious, membrane is very sensitive to detergents. Spreads through large droplets and does not kill cell to spread (buds) e. g. hiv, ebola, influenza. A naked virus capsid is made up of many repeating faces (each individually called a capsomer) The viral genome is used to classify viruses.
