1. non-cellular (not considered as living)
2. metabollically inert
3. obligate intracellular parasites- rely on the host for reproduction 
4. genetic info: DNA or RNA (single/ db strand) 
5. genetic info: encased within a protein " capsid" 

• helical 
• icosahedral

A. Head with DNA or RNA inside 

B. Collar

C. Tail

D. End plate

E. Tail fiber

1. Attachment: phage comes in contact with host cell
2. penetration: Injects genetic material in teh cell
3. Synthesis: phages are intracellular and hijack host machinery to synthesize
4. assembly: packaging new phage particles (package in capsid) 
5. lysis: release how cell (E.coli) lysis and releases new phage particles