PPT-RNA viruses Polarity (+ sense or – sense)

Size of genome Segmented or not Site of replication   FAMILIES of NEGATIVE STRAND VIRUSES   NONSEGMENTED STRAND VIRUSES   RHABDOVIRIDAE Rabies VSV amp Plant viruses   FILOVIRIDAE. Chapters 12 and 13. Viral Characteristics and Structure. Why Viruses aren’t Alive. General Characteristics of Viruses. Name derives from the Latin for “poison”. Obligatory intracellular parasites. What is a Virus?. Very small . Non-living particle. Made up of nucleic acid. . and proteins. Can only reproduce by infecting living cells. Do not carry out respiration, grow or develop. Structure. Viruses have an inner core which contains either RNA or DNA. HIV infected T-cell. Viral Structure. not . cells. small . infectious particles . w/. DNA or RNA enclosed . in a protein coat . (capsid). in . some cases. , a membranous envelope. Viral Genomes. genomes . Viruses Are Not Cells!. There are several structural and functional differences between cells and viruses. The structural differences include:. No nucleus. No cell membrane. No organelles. The functional differences include:. Lecturer. Dr Ashraf Khasawneh. Department of Biomedical Sciences. Virus infections are Universal …….. Introduction to Virology. A virus is an obligate intracellular parasite containing genetic material surrounded by protein. Viruses . A nonliving (?) particle made of proteins, nucleic acids, and sometimes lipids (fats). Viruses only reproduce by infecting living cells. Most viruses can only be seen with an electron microscope. EQ: Why are viruses considered to be non-
living?. Characteristics:. *Nonliving particles made of . nucleic acid. and a . protein coat . enlosed in a . capsid. shell... *In order to reproduce, all viruses must have a . © 2017 Pearson Education, Inc.. Introduction. A . virus . is an obligate, intracellular parasite . Viruses enter a . host. . cell. and use the host’. s biosynthetic machinery to reproduce and synthesize its proteins. VOCABULARY. Virus. Capsid. Envelope. Human . Immunodeficiency Virus (HIV. ). Influenza. Lytic Cycle. Lysogenic Cycle. Lysis. Retrovirus. Prerequisite questions. What are the eight characteristics which all living things have in common. arboviruses. ) are viruses that can be transmitted to man by arthropod vectors. . Arboviruses. belong to three families:. Togaviruses. . Bunyaviruses. e.g. . Sandfly. Fever. .. Flaviviruses. e.g. Yellow Fever, dengue, Japanese Encephalitis. Viruses are very small – smaller than the smallest cell.. They are usually surrounded by a capsid of proteins.. For replication, viruses rely on their host cells . ie. ., the cells they infect.. Most viruses exhibit a limited host range- they typically infect only specific types of cells of one host species.. CELL AUTONOMY. Plant.  development is critically dependent on the interactions between clonally unrelated . cell.  layers. . The cross-talk between layers can be addressed by studies of . cell autonomy. Dr.Luma. . amer. Viral genetics. Viruses are simple . creatures, . lacking an . energy-generating system . and having very limited . biosynthetic capabilities. . The smallest viruses have only a . few genes. Daniel Hodges, Tara Seymour, Emily Spurlin, and Rebecca Alexander. Department of Chemistry, Wake Forest University. Figure 4. . Schematic of structure reactions. 1M7 is added to flexible hydroxyl groups of the RNA and relative reactivity is measured so that structure can be deduced. Mortimer .