Biology, I Notes Outline NAME: ______

Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______

What is Virus

What is Virus: Characteristic • ______is the study of ______• Neither ______nor ______• They are ______, that is, they contain ___ cytoplasm or cellular organelle • No metabolism o Using ______machinery of the host cell for ______• No ribosomes of their own • Obligatory intracellular parasites  Require living host cells in order for multiplication • Can’t grow on artificial media • Has either ______or ______• ______to replicate Structure of a Virus Viruses are acellular and are obligate intracellular parasites. An intact infectious viral particle is: virion • A virion consists of: o ______: every virus has a core on ______(genes) . Called the genome of virus . Either RNA or DNA, but ______. Either nucleic acid may be ______or ______stranded o ______: every virus has a ______of ______called capsid around the ______. The capsid ______the genome . The capsid ______to the virus . Capsid is composed of protein subunits called capsomeres o ______: some viruses (enveloped viruses) have an ______of fat, protein and carbohydrates . Derived from cell ______of host cell . Some envelopes may have ______in order ______

2014-2015 DiMarcella 1 http://www.sglearnonline.com/virus.html Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______virus to host  Spikes are carbohydrate-protein complex, glycoprotein, with viral ______. Example of enveloped virus is the ______. Without envelope: nonenveloped viruses Classification of What is Virus • Viruses can store their genetic information in five different types of nucleic acid o Double-stranded DNA . This includes ______, adenoviruses, Herpes virus o Single-stranded DNA . once inside the host cell, it is ______to ______stranded DNA  Phage M13, Parvoviruses o Single-stranded RNA . Yellow fever and ______o Double stranded RNA o Single stranded RNA with ______. The ______is reverse transcribed into ______.  The DNA is transcribed into viral mRNA o ______What is Virus: Replication Cycle  ______to host cell  ______(penetration) o Enveloped viruses: . By endocytosis . By fusion o Non-enveloped viruses . By endocytosis only  ______o Uncoating is the ______of the viral ______from its ______once the virion is enclosed within the vesicle

2014-2015 DiMarcella 2 http://www.sglearnonline.com/virus.html Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______

 ______o ______of viral nucleic acid in the nucleus of the host cell by viral ______(may dissolve host genes to get ingredients) . Synthesis of viral protein, such as capsid: ______of host ribosomes and ______of viral protein by host enzymes  ______o ______of capsid and viral DNA to form a ______. Newly synthesized viral proteins migrate into the nucleus and are joined with the viral DNA to form virion  ______o Enveloped viruses escape one-by-one, taking along some host cell membrane for their envelope (a budding process) . Host cells may or may not be lysed Bacteriophage Virus  General information o Viruses that ______. For example ______o Can wipe out a bacterial culture o Also known as “______” o A lot of research has been conducted on about this topic o Phage replication total time range from ____ - ______. Approximately 50-200 new phages emerge o Multiply by two alternative mechanisms . ______cycle  Virus goes inside, ______and then ______. ______cycle  Virus DNA ______of the ______DNA and ______Lytic Cycle Stage . Attachment (adsorption) o ______to ______on bacterial cell wall

2014-2015 DiMarcella 3 http://www.sglearnonline.com/virus.html Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______. Penetration o ______is ______. Early Replication o ______starts to ______o Other ______. Late Replication o Production of components progress, as well as enzymes . ______o ______are now ______. Release o ______coded ______break down peptidoglycan in bacterial cell wall . Causes ______Some phages do not cause lysis and ______of the ______. Those viruses are called lysogenic phages o Lysogeny: the condition in which viruses and bacteria can ______o Virus incorporates its DNA or its RNA (via DNA) ______a chromosome of the ______cell o Each time the cell’s chromosome is reproduced, the virus is also propagated Lysogenic cycle . Host DNA is ______and viral genome remains latent in the cell o Latent means ______. Inactive bacteriophage is called ______o The prophage codes for proteins that suppress prophage genes, and renders the ______to more of the same phages . Prophage can be activated and excised (removed) later to enter a lytic cycle

2014-2015 DiMarcella 4 http://www.sglearnonline.com/virus.html Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______

Control of Viruses . Difficult because of ______of viruses: o few structures, no metabolism . Can be Killed by: o Steam autoclave, Gas autoclave, Some disinfectants, Powerful radiation Retrovirus-HIV . ______encode their own enzyme: ______o This enzyme utilizes ______to synthesize ______in the host cell . This newly synthesized viral DNA integrates into a host cell’s chromosome as a ______. HIV: Human Immunodeficiency ______o ______disease: ______. AIDS: Acquired Immunodeficiency Syndrome o Has single strand RNA, two identical strands of RNA . Once in host cell, RNA reversely transcribed into DNA and is incorporated into the host chromosome o Has envelope with spikes of gp120 which allows viruses to ______to CD4 receptors of ______o Integrated DNA . Either control the production of an active infection: new viruses bud from the host cell . Or remain ______in the host cell’s chromosome as a ______o The transmission of HIV is through direct contact with or the transfer of infected body fluids

2014-2015 DiMarcella 5 http://www.sglearnonline.com/virus.html Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______What are Viruses and Cancer . Several types of cancer are known to be caused by viruses o Example: HPV . Cancer: o Cancer results from the ______of cells . ______: cancer causing agents  Certain viruses may be carcinogenic o Approximately ____% of cancers are known to be ______o Development of cancer also involves ______and ______. Oncogenes are responsible to causing cancer in cell Oncogene Theory  Developed in the ______’s  Oncogene: a gene that can bring about ______o They are part of the host genome and can carry normal cellular functions  Examples: o Human papillomavirus (HPV): Cervical cancers . Vaccine is available o Hepatitis B virus (HBV): liver cancer o Epstein-Barr (EB): Burkett’s lymphoma Prions  An infectious particle that does not contain DNA or RNA o It is a ______particle o There are ______ Diseases are caused by the conversion of a normal host glycoprotein into an infectious form o Cause ______called spongiform encephalopathy in ______. Mad cow disease: bovine spongiform encephalopathy (BSE) o Causes neurological disease also in ______. Kuru, Creutzfeldt-Jakob disease (CJD) Viroids

2014-2015 DiMarcella 6 http://www.sglearnonline.com/virus.html Biology, I Notes Outline NAME: ______Viruses Date: ______Period: ______ Infectious particles of naked RNA only  ______ About ______- ______of the size of an average virus  So far, viroids are only linked with ______

2014-2015 DiMarcella 7 http://www.sglearnonline.com/virus.html