(U1) Viruses Flashcards
1
Q
How is a bacteriophage structured? (3)
A
- icosahedral protein capsid
- capsid contains DNA as the form of genetic code
- also a contractile sheath, baseplate and tail fibres - all made from protein
2
Q
What cells do bacteriophages target?
What do they do? (4)
A
- Bacterial cells
- attach by tail fibres to cell surface,
- then inject DNA from capsid
- DNA codes to form more capsid proteins
- bacterial cell bursts, many new phages released
3
Q
How is HIV structured? (4)
A
- rounded protein capsid - containing RNA as genetic code
- enzyme reverse transcriptase in capsid (which converts RNA to DNA)
- viral envelope consisting of lipid layer
- surface glycoproteins (antigens)
4
Q
What type of virus is HIV?
What type of cells do they target?
A
- Retrovirus
- helper T-cells (white blood cells)
5
Q
What size are viruses?
A
10nm - 300nm (microscopic)
6
Q
Are viruses living?
A
No; they are structures
