MBIOS 101 1nd EditionExam # 4 Study Guide Lectures: 32 - 38Lecture 32 1. Viruses - not alive like us or bacteria (need another host to replicate)2. Viruses are tiny – must use an electron microscope 3. Examples of Viruses:a. Chickenpoxb. Shinglesc. Small pox d. West Nile – must by carried by a specific mosquito type i. Combat thru educationii. Remove standing water – what about swimming pool?4. Viruses can be brutal but we cannot make a vaccine for each because it costs billions of dollars5. Marbling in tulips is a result of a virus6. More examplesa. Polio i. Spread through fecal material and thus pools (that’s why there was chlorine)ii. People used to have to be in the iron lung (early respirator) b. Rabiesi. Rabies is still a problem in India and some countries in Africa7. Viruses can be in our pets as well 8. Flu shots a. H1N1 – came out of nowhere, probably came from birdsb. When flus change species they get dangerous c. When making the flu vaccine, they try to predict which one will be the most prominent 9. Antibiotics cannot kill viruses10. We have some anti-viralsa. Herpes simplex b. HIV – takes a HIV cocktail Lecture 331. History of Virusesa. 1898 – microbiologist Dutch Martinus W. Beijerinck i. found disease in tobacco leafii. called agent filterable virusiii. Did a filter experiment on the tobacco leaf and discovered that thevirus could pass through the filter 2. Virusesa. Have their own DNAb. Examples –i. Wartsii. HPViii. Herpes Simplex iv. Parovirus 3. Virus characteristicsa. Obligate intracellular parasites of bacteria, protozoa, fungi, algae, plants, and animalsb. Ultramicroscopicc. Are not cells – very compact and economical d. Do not independently fulfill the characteristics of lifee. Need host cell to replicatef. Are inactive macromolecules outside of the host cell and active inside thehostg. Are geometrich. Basic structure consists of protein shell surrounding nucleic acid corei. Nucleic acid can be either DNA or RNA not bothj. Nucleic acid can be double stranded DNA, single stranded DNA, single stranded RNA and double stranded RNA k. Molecules on virus surface impart high specificity for attachemtn to host cell l. Multiply by taking control of host’s cells genetic material and regulating the synthesis and assembly of new virusm. Lack of enzymes for metabolic processesn. Lack machinery for synthesizing proteins4. Viral Anatomy a. Non-enveloped virus (naked virus) i. All it has is a structure called the capsomere and the nucleic acid b. Enveloped virus i. Spikes on the outside of the envelope for attachment c. Bacteriophage i. Inject DNA into celld. Life cycle i. Injection into cellii. Host cell1. Disease of host cella. Productive infection (more virus produced)b. Lysis of cell (cell dies) or release of cell (host cell multiplies)2. Genetic alteration of host cella. Latent state i. Nucleic acid of virus becomes a part of the host cell DNA b. Host cell is often modified and continues to modifyLecture 341. Viruses are very particular on what cells they infect 2. Receptor mediated endocytosis a. Locks onto cellb. The cell envaginatesc. The virus enters the cell 3. Some viruses can enter human cell because on something on the cell surface andsome cannot 4. Viruses enter cell and take over what is going on inside your cell 5. Virus can create a sort of slide and go directly into the nucleus through the cytoplasm 6. RNA and DNA virusa. RNA replicate in cytoplasmb. DNA replicate in nucleusc. This is the only difference, otherwise they operate the same 7. Bacteriophage a. Use these to target certain diseases b. Two routesi. Lytic cycle 1. Bacteria lands on bacteria2. Shots in nucleic acid3. Makes parts 4. Releases the virusii. Latent (Shingles, rabies, chickenpox can all enter these stages)1. Enters bacteria 2. Enters DNA of bacteria3. Bacteria replicates 4. New cells have viral DNA as well c. Anti-viral drug (attack life cycle)i. Block attachment or entry of virus1. Ex. Tamiflu – flu (this drug lessens the symptoms of the flu and does not cure it—but you have to give the medicine within 24 hours of getting the symptoms) ii. Block viral uncoating1. Ex. Amantidine – Flu2. Timing is everything for this one as well iii. Stop nucleic acid synthesis (RNA or DNA)1. Ex. Acyclovir –Herpes 2. AZT – HIV iv. Stop Reverse transcriptase 1. Ex. AZT- HIV v. Stop assembly of virus particle 1. Ex. Protease – HIV vi. Stop release of virus particle 1. Ex. Tamiflu – flu2. Amantidine – Flu d. Other methods of controli. Educationii. Vaccines Lecture 351. Vaccines are important to get2. A lot of viruses can be worse if you get them when you are older3. Viruses and immune system Ag+macrophage/dendrite goes to APCHumoral T-cell mediated Bcells T-cellsPlasma cells T cytotoxic – virus cells (kills cells that have virus in them), also works against TransplantsAntibodies (IgM, IgG, IgE..etc.) Natural Killer Cells—virus cells, transplantB memory cells T suppressor cell – shut system “off”4. T cytotoxic – ravenous cells5. Natural Killer cells – ravenous cells as well, attack virus cell and transplant6. T suppressor cell shut system off – regulates the T cytotoxic and natural killer cells7. There are particular times that you get vaccines a. Certain windows of time that they are more effective b. The antigen educates your immune system for life 8. HPV virus and vaccinea. Does not prevent cervical cancerb. First made for womenc. Then males wanted it d. Epithelial cells are different for males and females and so they had to make a new vaccine9. Immunitiesa. Active – get the diseaseb. Passive – mother to babyc. Artificial – vaccinesd. Passive artificial – accidently coming in contact with a disease, Doctor gives you a gamma globulin in case you acquired the disease, gives your immune system a jump start 10. Requirements for an Effective Vaccinea. It should have low level of adverse side effects or toxicity and not cause serious harm b. It should protect against exposure to natural, wild forms of pathogenc. It should stimulate both b cells (antibody) response and cytotoxic (t cells) response d. Long-term lasting effects (produce memory)e. Not require numerous does or boosters f. Inexpensive, have a relatively long shelf life and be easy to administer 11. Multiple types of administrationa. Injection- subcutaneous SQ b. Nasal spray c. Orald. Injection- Intramuscular IM 12. Types of vaccinesa. Whole bacteria – killedb. Whole bacteria –