dna dsdna ssdna acid dna nucleic ssdna peplomers proteins surface attach cell host peplomers proteins surface peplomers proteins spikes surface capsid capsomers hexons icosahedral triangular capsid capsomers icosahedral pentons round capsid hexons icosahedral pentons round triangular acid less nucleic rna stable less rna ssrna stable less rna stable dsrna less rna stable matrix proteins stabilize virus matrix proteins surface attach cell host proteins surface proteins spikes surface bilayer envelope phospholipid proteins bilayer matrix phospholipid proteins bilayer phospholipid proteins surface bilayer lipids phospholipid proteins bilayer phospholipid proteins acid dna dsdna nucleic capsid capsomers genome protect capsid covering genome protect capsid genome protect capsid genome nucleocapsid protect 3' 5' as cell mrna polarity positive same ssrna acid central core nucleic proteins acid central core nucleic viruses acid central core nucleic acid capsomers nucleic protect acid central core nucleic protect acid dna nucleic protect acid central core dna nucleic acid dna nucleic acid dna nucleic rna acid nucleic protect rna acid central core nucleic rna acid nucleic rna ssrna acid nucleic rna acid dsrna nucleic rna acid capsid nucleic nucleocapsid acid dna nucleic nucleocapsid acid nucleic nucleocapsid protect acid central core nucleic nucleocapsid acid nucleic nucleocapsid rna central core during na proteins replication stabilize aid during enzymatic functions na other proteins replication stabilize during na proteins replication stabilize actual during na perform proteins replication stabilize acellular ultramicroscopic viruses central core ultramicroscopic viruses intracellular obligate parasites ultramicroscopic viruses covering ultramicroscopic viruses capsomers hexons rod-shaped triangular capsomers protect rod-shaped capsid capsomers rod-shaped capsomers polypeptides rod-shaped capsomers cell host penetrate rod-shaped capsomers protomers rod-shaped capsomers pentons rod-shaped round attach capsomers cell host rod-shaped capsid helical negative polarity rod-shaped capsid capsomers helical rod-shaped capsid helical negative polarity ssrna negative polarity positive ssrna negative polarity rna ssrna polarity positive rna ssrna dsrna rna ssrna capsomers hexons protect triangular capsomers hexons triangular capsid capsomers hexons triangular capsomers hexons polypeptides triangular capsomers cell hexons host penetrate triangular capsomers hexons protomers triangular capsomers hexons pentons round triangular attach capsomers cell hexons host triangular acellular central core viruses acellular intracellular obligate parasites viruses acellular covering viruses aid central core enzymatic functions other proteins central core proteins actual central core perform proteins replication central core proteins viruses central core viruses central core intracellular obligate parasites viruses central core covering viruses capsid covering envelope covering envelope viruses bilayer covering envelope phospholipid bilayer envelope lipids phospholipid bilayer envelope phospholipid acid nucleic protect capsid capsomers protect capsomers polypeptides protect capsomers cell host penetrate protect capsomers protect protomers capsomers pentons protect round attach capsomers cell host protect capsid capsomers polypeptides capsid capsomers cell host penetrate capsid capsomers protomers capsid capsomers pentons round attach capsid capsomers cell host capsid capsomers covering capsid covering viruses capsid capsomers nucleocapsid capsid covering nucleocapsid aid enzymatic functions other proteins actual aid enzymatic functions other perform proteins replication intracellular obligate parasites viruses covering intracellular obligate parasites viruses ambisense negative polarity ssrna negative polarity ssrna most negative polarity rna ssrna viruses capsomers cell host penetrate polypeptides capsomers polypeptides protomers capsomers pentons polypeptides round attach capsomers cell host polypeptides ambisense polarity positive ssrna polarity positive ssrna most polarity positive rna ssrna viruses attach capsomers cell host proteins surface attach capsomers cell host pentons round ambisense most rna ssrna viruses ambisense rna ssrna capsomers cell host penetrate capsomers cell host penetrate protomers capsomers cell host penetrate pentons round attach capsomers cell host penetrate most rna ssrna viruses dna dsdna most viruses dna dsdna partial complete dna dsdna actual perform proteins replication capsomers pentons protomers round attach capsomers cell host protomers dna dsdna most partial viruses complete dna dsdna most viruses capsomers pentons round attach capsomers cell host attach cell host proteins spikes surface complete dsdna partial acid nucleic nucleocapsid bilayer lipids phospholipid