black10 - Obligate Intracellular Parasite Some bacteria are...

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Obligate Intracellular Parasite Some bacteria are obligate intracellular parasites For example, Chlamydia spp. All viruses are obligate intracelluar parasites “Obligate Intracellular Parasite” means that these would-be replicators must locate and invade a cell in order to replicate Outside of cells viruses are nearly inert; they don’t even have cells (e.g., plasma membrane, ribosomes, cytoplasm, etc.)
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Virus (Definition) Viruses are… “. ..infectious agents of small size and simple composition that can multiply only in living cells of animals, plants and bacteria [plus fungi & protozoa]. Viruses are obligate parasites that are metabolically inert when they are outside their hosts. They all rely, to varying extents, on the metabolic processes of their hosts to reproduce themselves . The viral diseases we see are due to the effects of this interaction between the virus and its host cell (and/or the host’s response to this interaction). Encyclopedia Britannica
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Virus Relative Size (Small) 10 -2 - (1 cm) 10 -3 - (1 mm) 10 -6 - (1 µm) 10 -9 - (1 nm) 10 -10 - (1 …) 10 -4 - 10 -5 10 -7 10 -8 Poxvirus Viruses Animal cells Bacteria Proteins Atoms Light microscope Electron microscope X-ray NMR Note that Viruses are not cells Repeat after me, “Viruses are not cells” And “Antibodies” are not “Antibiotics”, either!
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Virions (Virion Particle) The Virion is what defines a virus as a virus A Virion is the extracellular state of a virus The job of Virions is to find new cells to infect As such, Virions are a durable state that is “designed” to attach to susceptible cells The Virion is then responsible for translocation of the virus genome into the cell The Virion consists of a DNA (or RNA) genome surrounded by Protein that, in turn, may be surrounded by a Lipid Bilayer(s) The Protein layer is called a Capsid The Lipid Bilayer is called an Envelope
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Capsid (Nucleocapsid) The Capsid is the protein shell surrounding the virus nucleic-acid genome A Nucleocapsid is that combination of protein capsid and nucleic-acid genome Capsids consist of multiple subunits of one or more types of protein Capsomere(s) = capsid protein subunits For viruses with complex morphologies the
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black10 - Obligate Intracellular Parasite Some bacteria are...

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