Virus Structure, Classification, and Cycles of Infections Matt Resnick, Riley Fosnot, Adam Fields, Brandon Archibald

Overview What is a virus? - What is the structure of a virus? What are the different kinds of viruses? - How do these viruses function? Lytic vs Lysogenic infections  Vaccinations effects on viruses

What is a Virus? A microscopic, nonliving particle that survives off of host-cells Simple structure made up of proteins and genetic material Unable to survive on its own Reproduces by binding to living cells and spreading genetic material Kill host cells as they spread. MR

How do viruses differ All viruses look different in terms of size and structure Capsid membranes vary in thickness Genetic material varies from tens to hundreds of genes. Proteins can only bind to one specific type of host cell MR

2 universal virus structures 1. Capsid- Protein coat that encases the genetic material of a virus Hard outer layer which protects the genetic material and binds to host cell 2. Genetic Material- DNA or RNA  Enters cell and reproduces to make new viruses Kill host cells by spreading genetic material MR

Are Viruses considered living? No, don't fit criteria for a living organism Not made of cells and cannot reproduce on their own Don’t have a metabolism and don't maintain homeostasis Don't grow and develop MR

Adenovirus A virus which infects adenoid cells Include: eye lining, intestines, throat Respiratory infection which affects mostly children Sore throat, pink eye, diarrhea, cough Usually goes away in a few days on by ITSELF RF

Bacteriophage A virus that infects BACTERIA by attaching to the surface of the bacteria Inserts it's on DNA and begins replicating Can turn harmless bacteria into harmful bacteria Food poisoning & Bacterial Infections  Usually resolves itself in a few days  RF

Retrovirus Infects host(T-Cells) by RNA (Reverse Transcriptase) Takes over cell and replicates  Disease: HIV --> AIDS Medicine used to stop multiplying HIV cell RF

Reverse Transcriptase How retroviruses infect host cell Turn RNA into DNA Using the virus RNA implanted into nucleus RF

Lytic Infections Virus enters the bacteria cell and duplicates Causes cell to burst and breakdown "lyse" Injects DNA beginning mRNA process  RNA translated into viral proteins and destroy cell DNA Host cell = Destroyed AF

Lysogenic Infections Host cell is not immediately taken over Viral nucleic acid inserted in host cell's DNA (Prophage) Copied along w/ host cell DNA Viral DNA and host cells multiply Daughter cells derive from original host DNA AF

Prophage Bacteriophage DNA imbeds in bacterial host DNA Prophage may remain in host DNA for generations Triggered by radiation, heat, and certain chemicals Removes from host cell DNA to direct synthesis of virus Lysogenic infection becomes active lytic infection AF

Viral Genes are Transcribed by host cell Lytic  Lysogenic Viral Genes are Transcribed by host cell Proteins and nucleic acids assemble new viruses Virus injects DNA into bacterium Create Prophage Viral DNA inserts itself in bacterial chromosome Prophage may replicate w/ bacterium Virus infection cycle Can cause spreading to body  can have a prophage AF

Why Vaccinate? Vaccination: The injection of a killed microbe that stimulates the immune system to fight the microbe Parents of vaccinated children argue of the lasting benefits of vaccination Viruses that once killed thousands of people have been eliminated or close to extinction Immunization is the objective of vaccines Vaccinations are done by injections  BA

The Numbers There has been a steady decline in deaths caused by vaccinated preventable diseases In the 1980's, there had been 350,000 cases of polio each year There were 42 cases of polio in 2016 2-3 million deaths have been avoided due to vaccination  Vaccines cost $.10-$20 in developing countries BA

Why Not Vaccinate?  Parents are concerned about vaccines containing toxins Mercury, aluminum salt, and formaldehyde "Vaccines cause autism" Vaccine manufacturers can’t be sued for making kids sick/big pharma. BA

Research  8 children whose first symptoms of autism appeared a month after receiving an MMR vaccine. MMR vaccine caused intestinal inflammation  Nonpermeable peptides make into bloodstream 44 samples of vaccines found dangerous contaminants BA

ABC's What are two characteristics of a virus? A. Comprised of cells and reproduce B. Kill living cells and maintain homeostasis C. Grow and reproduce D. Nonliving and survive off of host cell

ABC's Viruses are particles that are made up of 2 structures, ________ and ________. A. DNA and RNA B. Capsid and Genetic Material C. Head and Tail D. Capsid and Membrane MR

ABC's Adenovirus affects MAINLY what group of people? A. Young children B. Old people C. People of European decent D. People who contract the H.I.V. virus RF

ABC's Retroviruses affect what type of cells? A. Adenoid cells B. Throat, intestines, eye lining, etc. C. T-Cells D. All of the above RF

The bursting and breaking down of a cell is known as what? ABC's The bursting and breaking down of a cell is known as what? A. Prophage B. Lytic Infection C. Lyse D. Denaturing AF

ABC's When viral nucleic acid is inserted into a host cell it is called a...? A. Prophage B. Viral Protein C. Lysogenic Infection D. Virus AF

Which dead microorganism is present within vaccinations? ABC’s Which dead microorganism is present within vaccinations? A. Archaea B. Bacteria C. Protozoa D. Microbe MR

ABC's A. Blindness B. Autism C. Diabetes D. Heart disease What is one of the major concerns associated with vaccines by anti- vaccinators?       A. Blindness  B. Autism     C. Diabetes              D. Heart disease BA

Overview What is a virus? - What is the structure of a virus? What are the different kinds of viruses? - How do these viruses function? Lytic vs Lysogenic infections  Vaccinations effects on viruses