PPT-Lab 7: introduction to viruses

Asst lec Mariam Ahmad Ali Introduction to Viruses Viruses are the smallest infectious agents 20 300 nm in diameter containing only one kind of nucleic acid RNA or DNA as their genome The nucleic acid is encased in a protein shell which may be surrounded by a lipid . Embryonated. Egg. Viruses do not fall in the category of unicellular . microorganism. They . are obligate intracellular parasites and lack the . machinery . necessary for protein and nucleic acid . synthesis. A . virus. is a small . infectious agent. that can replicate only inside the living cells of organisms. Most viruses are too small to be seen directly with a . microscope. . Viruses infect all types of organisms, from . DNA Enveloped . Viruses. I. Objectives. In this lecture you will learn about properties, pathogenesis, clinical picture and diagnosis of: . Herpesviruses. . (HHVs 1 to 8). Poxviruses. Smallpox Virus. Infectious Agents of Animals . and Plants. Chapter 14. What am I?. Structure and Classification of Animal Viruses. Classification of animal viruses. Taxonomic criteria based on. Genomic structure. DNA or RNA. 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 . Chapter 18. Are Viruses Alive?. As a group discuss for 1 minute. Be able to defend your answer for the class!. Are . VIRUSES. alive?. Growth and Development. Reproduce. Change Over Time. Obtain and Use Energy. 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. What do viruses need to reproduce?. Other viruses. Host organisms. A nutrient medium. An enzyme solution. Which characteristic do viruses possess in common with living cells?. They contain a nucleus and organelles.. Embryonated. Egg. Viruses. Viruses do not fall in the category of unicellular . microorganism. They . are obligate intracellular parasites and lack the . machinery . necessary for protein and nucleic acid . 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 . Why is starch agar used?. -To see if saliva was present and broke down the starch.. Positive control . –used to show what the change looks like. Negative control. – used to what no change looks like. 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. Viruses consist of a nucleic acid (either DNA or RNA) associated with proteins encoded by the nucleic acid. The virus may also have a lipid . bilayer. membrane (or envelope) but this is acquired from the host cell, usually by budding through a host cell membrane. If a membrane is present, it must contain one or more viral proteins to act as . As a group discuss for 1 minute. Be able to defend your answer for the class!. Are . VIRUSES. alive?. Growth and Development. Reproduce. Change Over Time. Obtain and Use Energy. Maintain Homeostasis.