PPT-Viruses

CLS 212 Medical Microbiology History Through the 1800s many scientists discovered that something smaller than bacteria could cause disease and they called it virion Latin word poison . 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 . 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. Other . Acellular. Infectious Agents. 1. 6. Copyright © McGraw-Hill Global Education Holdings, LLC. Permission required for reproduction or display.. Acellular. Agents. Viruses . – protein and nucleic acid. Prabhaker Mateti. Mateti, Viruses, Trojans and Worms. 2. Virus Awareness. Virus Bulletin . http://www.virusbtn.com/. . Technical journal on developments in the field of computer viruses and anti-virus products . copyright cmassengale. 2. Are Viruses Living or Non-living?. Viruses are both and neither. They have . some properties of life but not others. For example, viruses can be killed, even crystallized like table salt. 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:. Where the name came from. This is a phrase coined from biology to describe a piece of software that behaves very much like a real virus (only it spreads from computer to computer rather than people!).. 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. Are Viruses Living or Non-living?. Biologists consider viruses to be non-living because:. Are not cells. Do not grow or respond to their surroundings. Cannot make food, take in food, or produce wastes. STRUCTURE. A core nucleic acid - DNA or RNA. Nucleic Acid surrounded by a protein, called a capsid.. CLASSIFICATION. By genomes: DNA viruses, RNA viruses or retroviruses . (any . of a group of RNA viruses that insert a DNA copy of their genome into the . 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 .