3 A. INTRODUCTION The Common Cold: What causes it? A common cold is an illness caused by a virus infection located in the nose.Introduction (p.282)Common Cold, what causes it? How does it enter the body? Best treatment? Doesn’t kill virus, treats symptoms.Fast Facts:** Cold viruses live only in the noses of humans and not in animals except chimpanzees and other higher primates.** A cold virus is deposited into the front of the nasal passages by contaminated fingers or by droplets from coughs and sneezes.** Small doses of virus (1-30 particles) are sufficient to produce infection.** Cold viruses can only multiply when they are inside of living cells. When on an environmental surface, cold viruses cannot multiply. However, they are still infectious if they are transported from an environmental site into the nose.** Cold symptoms are due mainly to the body's response to the infection. When a nasal cell is infected by a cold virus, the body responds by activating parts of the immune system and some nervous system reflexes
4 B. Virus Characteristics 1. STRUCTUREDNA insideChicken PoxHuman InfluenzaB. Characteristics1. Structure (p283)a. composed of genetic materialb. classified as RNA or DNA (not both) found in head of virusc. enclosed in a protein coat or capsidd. very small, different shapes (p. 284, Table 19-2)FAST FACT:The protein that forms the protective capsid surrounding the West Nile virus genetic material may contribute to the deadly inflammation associated with the virus. West Nile virus, which has rapidly spread across the United States, causes neurological symptoms and encephalitis, which can result in paralysis or death. According to researchers at the University of Pennsylvania School of Medicine, the West Nile virus capsid (WNV-Cp) is a destructive protein that can trigger apoptosis – the automatic self-destructive program within cells – inside infected cells, possibly adding to the damage caused by the virus.Rabies VirusHIV
5 2. Two Types of Viruses2. Two TypesVirulentTemperate
6 Lytic Cycle of a Virulent Virus --Causes disease immediately Infectious Diseases: Viral InfectionInfectious Diseases: Viral Infection2. Typesa. virulentb. temperateThis slide shows virulent virus cycle: (animation will begin on its own- after slight delay)Absorption: Virus attaches itself to the cell.Entry: Enzymes weaken the cell wall and nucleic acid is injected into the cell, leaving the empty caspid outside the cell. Many viruses actually enter the host cell intact.Replication: Viral DNA takes control of cell activity.Assembly: All metabolic activity of the cell is directed to assemble new viruses.Release: Enzymes disintegrate the cell in a process called lysis, releasing the new viruses.
7 Lysogenic Cycle of a Temperate Virus --Does not cause disease immediatelyb. TemperateLysogenic Cycle of a Temperate VirusActivated to produce new virusesRemains in cell2. Typesa. virulentb. temperateThis slide shows temperate virus cycle:The virus attaches itself and injects its DNA into the cell.The viral DNA attaches itself to the host DNA, becoming a new set of cell genes called a prophage.When the host cell divides, this new gene is replicated and passed to new cells. This causes no harm to the cell, but may alter its traits.Now there are two possibilities:A. The prophage survives as a perminant part of the DNA of the host organism.B. Some external stimuli can cause the prophage to become active, using the cell to produce new viruses.
8 3. Are viruses living? What are all living things made of? What do all living things need?How does environment affect living things?How do living things reproduce?3. Living or Non-living?non-living – Why?They have some characteristics of life but not allNo nucleus, cytoplasm, organelles, cell membrane, do not reproduce by mitosisAre not capable of carrying out cellular functions – are not cells.can only reproduce by invading a cell1.uses the enzymes and organelles of host cells to make more virues2. Obligate intercellular parasites- require a host cell to reproduce.Spread by wind, in water, in food or blood and other bodily secretionsHow do characteristics of viruses compare to that of living organisms?
9 4. Virus Reproduction Process AbsorptionEntryReplicationRelease4. Virus ReproductionClick play button to open animation (uses Quicktime player as default)View Animation
10 C. Virologist1. Growing cells in a controlled medium: ________________Tissue culture2. Serology3. _____________is used to separate fragments of molecules based on charge and size.- study of biological fluids used to determine antibody responseElectrophoresisd. Studies bacteriophages.C. Virologist- people who study virusesa. tissue culture- growing cells in a controlled mediumb. serology – study of biological fluids used to determine an organism’s antibody responsec. electrophoresis- a process that separates fragments of large molecules, such as proteins, rDNA on basis of charge and size.** (click once when ready for electrophoresis animation)d. study bacteriophages- the most commonly studied virus that infect bacteria
11 D. Diseases Common Cold ___________________ * 200 kinds of Viruses 1. The Common ColdSymptoms include nasal discharge, obstruction of nasal breathing, swelling of the sinus membranes, sneezing, sore throat, cough, and headache.
12 Polio 2. ________________ Poliomyelitis is a crippling disease of spinal nerve cells caused by poliovirus infection.The disease can strike non-immune persons of any age but affects mainly children under the age of three, and causes paralysis in one case of every 200 to 1000 infections. Preventable by vaccination. 2. Polio
13 Tobacco Mosaic 3. ______________________ 3. Tobacco Mosaic Symptoms induced can include mosaic, mottling, necrosis, stunting, leaf curling, and yellowing of plant tissues.
14 STD AIDS 4. ___________ 4. AIDS Acquired immunodeficiency syndrome, is caused by the human immunodeficiency virus, or HIV.HIV destroys the body's ability to fight infections by attacking cells of the immune system.
15 Rabies 5. ______________ 5. Rabies The vast majority of cases reported to the Centers for Disease Control and Prevention (CDC) each year occur in wild animals like raccoons, skunks, bats, and foxes.Infects the central nervous system, causing encephalopathy and ultimately death.5. Rabies
16 Cold Sore 6. ______________ 6. Cold Sore (Herpes simplex ) Between % of all people possess this virus and is spread through direct contact with an infected individual.Once the virus has entered the body, it cannot be removed.Only 10% of HSV1 infected people ever develop a sore.6. Cold Sore
17 Shingles 7. _____________ An acute infection caused by a reactivation of the varicella zoster virus, which also causes chicken pox.7. ShinglesIt usually occurs during adulthood after exposure to chicken pox in childhood. The chicken pox virus remains dormant in the body.
18 For every 1,000 children who get it, 1 or 2 will die from it Measles8. _____________Most infected children will have a rash, high fever, cough, runny nose, and watery eyes.For every 1,000 children who get it, 1 or 2 will die from itSpreads so easily that any child who is not immunized will probably get it, either now or later in life.8. Measles
19 Warts9. ___________Non-cancerous skin growths caused by a viral infection in the top layer of the skin. Viruses that cause them are called human papillomavirus (HPV).9. WartsSTD
20 STD Herpes 10. _______________ 10. Herpes (Simplex2) HSV-2 usually produces only mild symptoms or signs or no symptoms at all.However, HSV-2 can cause recurrent painful genital sores in many adults, and HSV-2 infection can be severe in people with suppressed immune systems.Regardless of severity of symptoms, genital herpes frequently causes psychological distress in people who know they are infected.10. Herpes (Simplex2)
21 Hepatitis B 11. _____________ 11. Hepatitis B The most common serious liver infection in the world.It is caused by the HBV virus that attacks the liver.HBV is 100 times more infectious than the AIDS virus. Yet, can be prevented with a safe and effective vaccine.
22 E. Treatment/Prevention 1. VaccineAnitbodies ProducedGuard/Fight Real DiseaseVaccine Given2. InterferonE. Treatment/Prevention1. Vaccine- substance containing a weakened or killed strain of a virus2. Interferon- a protein that inhibits the reproduction and speed of viruses
24 A. Bacteria Characteristics MONERA1. Kingdom _________________A. Bacteria CharacteristicsKingdom MoneraIntroduction
25 What is absent in this cell? 2. ProkaryoticWhat is absent in this cell?2. Prokaryotic- no nucleus or membrane bound organelles
26 Microscopic 3. ________________ How big are bacteria? 4. Where do they live?3. Microscopic (click on “Microscopic” to view the scale of bacteria, will open internet website independently of powerpoint).4. Live in nearly every environment(hot springs, deep sea vents, Antarctic ice, mouth, animals, people, soil, everywhere!)
27 Spherical Spiral Rod 5. What shape are they? a._______________ b._______________c._______________a.b.c.SphericalSpiralRodThe word “spiral” is hyperlinked to a short video.5. Shapea. spherical- coccib. spiral- spirillic. rod- bacilli
28 6. Groups Staphylo Strepto a. _________________: forms clusters StaphylococcusStreptob. _________________: forms filaments or chains6. Groupsa. staphylo –form clusters (i.e. staphylococcus)b. strepto – forms filaments or chains (i.e. streptococcus)Streptococcus
29 -Some are rigid, Some flexible 7. Have Cell Walls-Some are rigid, Some flexible8. Form Endospores in Harsh Conditions7. Have Cell Walls8. Form Endospores in Harsh Conditions
30 HETEROTROPHS VS. AUTOTROPHS 9. Movementflagella10. NutritionHETEROTROPHS VS. AUTOTROPHS9. Movement – flagella (Click on “movement to view animation”)10. Nutritiona. hetertrophic – depend on other organisms for food1. Parasitic – take nutrition from living things2. Saprophyte – feed on dead, decaying materialb. autotrophic – produce their own food1. Photoautotrophic – use sunlight as a source of energy2. Chemoautotrophs-a. use energy from chemical reactionsb. nitrogren fixation- process by which gaseous N2 is converted to ammonia compounds (ex. NH4, NO3)_____________: Take nutrition from other living organisms____________: feed on dead and/or decaying matter_____________: use the sunlight as a source of energyPhoto-Autotrophs_____________: use energy that results from a chemical reactionChemo-AutotrophsParasiticSaprophyte
31 11. Respiration in Bacteria Obligate Anaerobesa. ____________- cannot survive in the presence of oxygen.Facultative Anaerobesb. ____________- can live with or without oxygen.11. Respiration in Bacteriaa. obligate anaerobes-cannot survive in the presence of oxygenb. facultative anaerobes- live with or without oxygenc. obligate anerobes-cannot survive without oxygenObligate Aerobesc. ____________- cannot survive without the presence of oxygen.
32 12. Reproductiona. __________________: (asexual reproduction) one cell splits into two cells.Binary Fissionb. __________________: (sexual reproduction) exchange of genetic material between two bacteria.“binary fission” is linked to a short video showing fission – click on the word.The click on black box to see and hear video12. Reproductiona. binary fission- asexual process, one cell splits into two cellsb conjugation- sexual process, exchange genetic material between two bacteriaConjugation
33 B. Harmful Bacteria TOXIN PATHOGEN 1. _________________:an organism that causes diseaseTOXIN2. _________________:poisonous substance that disrupts the metabolism of the infected organismB. Harmful bacteria1.. Pathogen- an organism that causes disease2. toxin- poisonous substance that disrupts the metabolism of the infected organism.a. endotoxin- found in cell walls of some acteria and causes fever, weakness, damage to circulatory systemb. Exotoxin- secreted into areas surrounding the bacteria- very potent poisonsEndotoxinExotoxin
34 3. Disease a. Anthrax Cutaneous Inhalation A . Anthrax- fatal disease of sheep and cattle***Click on animations at left to see short animation of two forms of anthrax- narration describes each, volume/speakers will be needed to hear these animations (Cutaneous anthrax, Inhalation Anthrax). Two more videos continue after the inhalation one if you want to see them. The third is linked to the word “anthrax” and the fourth is linked to the picture on the right.Inhalation
43 ANTIBIOTICS 4. Treatments Penicillium mutate Inhibit growth of some bacteria________________________ - product of fungusBacteria can _______________to become resistant to antibioticsPenicillium4. Treatments-antibioticsa. inhibit growth of some bacteriab. Penicillium – product of fungusc. bacteria can mutate to become resistent to antibioticsmutate
47 Pathogens Fungus 2. Virus 3. Protozoan 4. Bacteria 5. Invertebrates Athletes Foot2. Virus3. ProtozoanMalariaMalaria 3Malaria 4Pathogens1 fungus-athletes foot2 virus3 protozoa- malaria/african sleeping sickness (click on malaria photo for video 1, click on “malaria” for video 2, click on “malaria 3” for video 3, and click on “malaria 4” for malaria 4 video.4 bacteria5 invertebrates- Trichonosis- worm in pork muscle4. Bacteria5. InvertebratesTrichonosis
48 B. ToxinsChemical substances harmful to the normal functioning of cells_______________- disrupt the transmission of nerve impulses.NeurotoxinsB. ToxinsChemical substances harmful to the normal functioning of cellsNeurotoxins-disrupt the transmission of nerve impulses
49 C. Transmission Air Water Human Contact Arthropods C. Transmission 1 air- spores, droplets, dust2 water3 human contact4 arthropods – lice, ticks, fleas
50 D. Defense 1. First Level of Response: D. Defense 1. First level of defense-skin, mucus glands, HCl in stomach
51 2. Phagocytosis 2 phogocytosis **Picture to left is WBC ** Animation on right will start process of phagocytosis automatically during slideshow
52 3. Fever 4. Interferon 5. Antigen 6. Immunity 3. Fever- kills some pathogens4. Interferon- a protein which inhibits the reproduction of viruses5 Antigen- causes an antibody to be produced on antibody reaction- very specific6. Immunity- resistance to a specific pathogen –Allergic reaction to the antigena Natural Immunity- present at birthb Acquired Immunity- after birth1 vaccination2. antibiotics
53 E. AIDS acquired immunodeficiency syndrome 1. CausedVirus: HIV (human immunodeficiency virus )Disruption of the proper functioning of immune systemVideo will appear in black box on its own – be patient. You will need sound.HIV
54 other body fluids containing blood 2. Transmission a. Sexual Contact b. Needles/Syringes c. Mother to Infantbloodsemenvaginal fluidbreast milkother body fluids containing blood
55 3. Viral Action 3. Viral Action Virus enters bloodstream to get into bodyPhagocytes try to destroy virus but don’t harmT4 cells attach virus, but virus enters T4 cell unharmedAntibodies attack virus but virus is unharmedMay remain dormant for up to 10 years in T4 cellsBecomes active and goes through lytic cycle – Lysis occurs and it spreads to other T4 cellsanimation of cycle
56 4. Effects on Immune Disruption Virus enters bloodstreamPhagocytes try to destroy virusT4 cells attack virus but virus enters T4 cell unharmedAntibodies attack virus but virus is unharmedMay remain dormant up to 10 Years in T4 cellsBecomes Active—Lytic Cycle and spreads to other T4 cells
57 “What can be done to prevent the spread of the disease?” 5. Risk and Prevention“Who is at risk?”“What can be done to prevent the spread of the disease?”Click on What can be done… for a short video You need to download Real One Player – free from the web- in order to play that video.Click on internet site to take a quiz to see how much students know about risk and preventionSource : American Assciation for World Helath
58 Video will start on its own when you click the middle bottom picture.