1. Viruses Viruses An infectious agent that is unable to grow or reproduce outside a host cell. It is considered non-living Virology is the study of viruses The Common Cold

2. Virus Shapes Helix Helix Coiled spring Coiled spring Rabies, measles, and tobacco mosaic virus Rabies, measles, and tobacco mosaic virus Icosahedron Icosahedron 20 faced Herpes, chickenpox, and polio

3. Virus Structure Viruses are extremely small Viruses are extremely small They have a : They have a : Nucleic acid (DNA or RNA) Nucleic acid (DNA or RNA) Capsid - A protein coat that comes in many shapes Capsid - A protein coat that comes in many shapes Protein tail -used to infect host Protein tail -used to infect host Capsid/

4. Structure of Influenza Virus Protein Glycoprotein Capsid Protein RNA Envelope Used to attach to host cell

5. FamilyVirusDisease AdenovirusCommon cold Flavivirus Hepatitis C (non-A, non-B) Yellow fever Hepatitis Hepatitis, hemorrhage HepadnavirusHepatitis B virus (HBV)Hepatitis, liver carcinoma Herpesvirus Epstein-Barr virus (EBV) Herpes simplex type 1 Herpes simplex type 2 Human herpesvirus 8 (HHV8) Mononucleosis, nasopharyngeal carcinoma Cold sores Genital lesions Chicken pox, shingles PapovavirusHuman papillomavirus (HPV)Warts, cervical carcinoma Paramyxovirus Measles Mumps Parainfluenza Measles Mumps Common cold, ear infections PoxvirusOrthopoxvirusSmallpox (eradicated) Retrovirus Human immunodeficiency virus (HIV) Human T-cell leukemia virus (HTLV-I) Acquired immunodeficiency syndrome (AIDS) Adult T-cell leukemia, lymphoma, neurologic disease RhabdovirusRabies

6. Viruses and Their Hosts When a virus meets a host cell, it can insert its genetic material into its host, taking over the host's functions When a virus meets a host cell, it can insert its genetic material into its host, taking over the host's functions The infected cell produces more viral proteins and genetic material instead of its usual products The infected cell produces more viral proteins and genetic material instead of its usual products

7. Phases Lysogenic phase - viruses are dormant inside host cells for long periods. Lysogenic phase - viruses are dormant inside host cells for long periods. No change in host. No change in host. Lytic phase - The virus is stimulated Lytic phase - The virus is stimulated new viruses are formed, self-assemble, and burst out of the host cell, killing the cell and going on to infect other cells. new viruses are formed, self-assemble, and burst out of the host cell, killing the cell and going on to infect other cells.

11. Two Ways to Control Viruses Vaccination – A solution with a harmless version of a virus causes an immune response when released into the body. Vaccination – A solution with a harmless version of a virus causes an immune response when released into the body. The body begins to produces antibodies against that virus The body begins to produces antibodies against that virus Antiviral Drugs – Drugs that interfere with viral nucleic acid synthesis Antiviral Drugs – Drugs that interfere with viral nucleic acid synthesis Antibiotics - Amoxicillin Antibiotics - Amoxicillin

12. Acquired Immunity – An immunity that develops after exposure 2 kinds: 2 kinds: Active Immunity – Active Immunity – Body is exposed to pathogen and begins to produce antibodies against that particular pathogen Body is exposed to pathogen and begins to produce antibodies against that particular pathogen Passive Immunity – Passive Immunity – Antibodies are transferred from another source, mothers milk Antibodies are transferred from another source, mothers milk Body does not have to be exposed to pathogen to develop antibodies Body does not have to be exposed to pathogen to develop antibodies

13. Viral Mutations Viruses are able to rapidly mutate Viruses are able to rapidly mutate Flu Flu HIV HIV Attacks white blood cells – the cells that protect our bodies from germs and infections Attacks white blood cells – the cells that protect our bodies from germs and infections HIV is latent until a secondary infection triggers a response HIV is latent until a secondary infection triggers a response Kills white blood cells Kills white blood cells HIV has a high rate of replication and mutation so antibiotics and vaccines do not work HIV has a high rate of replication and mutation so antibiotics and vaccines do not work

14. Disease and Immunity TB HerpesPolioMeasles

15. Pathogens – Causes of Disease If a foreign invader enters the body and is allowed to multiply – disease results If a foreign invader enters the body and is allowed to multiply – disease results (viruses, bacteria, parasites, fungi, invertebrates, or protists) (viruses, bacteria, parasites, fungi, invertebrates, or protists) Antigen is a potential pathogen that provokes an immune response Antigen is a potential pathogen that provokes an immune response Disease causes the body to malfunction. Disease causes the body to malfunction. If a disease is infectious, it can spread from host to host If a disease is infectious, it can spread from host to host

16. White Blood Cells (WBC) Phagocytes – surround and engulf, they are the most common Phagocytes – surround and engulf, they are the most common Neutrophils - early response Neutrophils - early response Macrophages – long term response for chronic illnesses Macrophages – long term response for chronic illnesses

17. Lymphocytes T cells and B cells made in bone marrow and accumulate in lymph nodes T cells and B cells made in bone marrow and accumulate in lymph nodes T cells recognize and attack specific antigens T cells recognize and attack specific antigens Helper T cells are able to link to antigens and activate the killer T cells which destroy diseased cells Helper T cells are able to link to antigens and activate the killer T cells which destroy diseased cells B cells produce antibodies to destroy disease causing substances B cells produce antibodies to destroy disease causing substances Antibodies are proteins that are able to fight infection Antibodies are proteins that are able to fight infection

19. Memory Cells T cells and B cells that remain in the body after an infection has been destroyed. T cells and B cells that remain in the body after an infection has been destroyed. They provide the body with active immunity against further invasion They provide the body with active immunity against further invasion

20. The Body’s Reactions The first defense is our skin and mucous membranes The first defense is our skin and mucous membranes Sweat and oil is toxic to some bacteria Sweat and oil is toxic to some bacteria Mucus will trap invaders Mucus will trap invaders Fever – an elevated body temperature will suppress bacterial growth, inactivate invaders enzymes, and initiate white blood cell response Fever – an elevated body temperature will suppress bacterial growth, inactivate invaders enzymes, and initiate white blood cell response Normal = 98.6 degree F / 37 degrees C Normal = 98.6 degree F / 37 degrees C

21. The Body’s Reactions Inflammatory response Inflammatory response Injured cells release chemical alarm signals Injured cells release chemical alarm signals Capillaries respond by swelling and leaking fluid and white blood cells Capillaries respond by swelling and leaking fluid and white blood cells Swelled area is warm Swelled area is warm Phagocytes (Pathogen eaters or WBC) arrive to attack Phagocytes (Pathogen eaters or WBC) arrive to attack Pus in wounds is dead pathogens Pus in wounds is dead pathogens

22. Bacteria Classification Two Kingdoms: Two Kingdoms: 1. Eubacteria – most common bacterial forms 2. Archaebacteria – Most primitive bacterial forms that live in extreme environments

23. Kingdom Eubacteria Most common Most common 3 basic shapes: 3 basic shapes: Rod Rod Sphere Sphere Spiral Spiral Prefix strep = Chains Prefix strep = Chains Prefix staphlo = Clusters Prefix staphlo = Clusters

24. Characteristics of Bacteria Mode of Nutrition Mode of Nutrition Heterotrophic – feed on organic matter Heterotrophic – feed on organic matter Autotrophic – Produce their own food Autotrophic – Produce their own food Oxygen requirements Oxygen requirements Anaerobic Vs. Aerobic Anaerobic Vs. Aerobic pH and Temperature pH and Temperature Each species of bacteria has specific requirements Each species of bacteria has specific requirements

25. How Bacteria Cause Disease 1. They produce toxins 2. They destroy body tissues by secreting digestive enzymes 3. The release of toxins and enzymes interferes with normal body functions Staph infection

26. Antibiotics and Bacteria Natural antibiotics are derived from chemicals that bacteria and fungi produce Natural antibiotics are derived from chemicals that bacteria and fungi produce These chemical protect the bacteria from invaders These chemical protect the bacteria from invaders Antibiotics are specifically designed to interfere with the cellular functions of bacterial which will inhibit their growth Antibiotics are specifically designed to interfere with the cellular functions of bacterial which will inhibit their growth Penicillin – interferes with cell wall synthesis Penicillin – interferes with cell wall synthesis Tetracycline – interferes with protein synthesis Tetracycline – interferes with protein synthesis

27. Antibiotic Resistant Bacteria They destroy antibiotics or prevent the antibiotic from entering the cytoplasm They destroy antibiotics or prevent the antibiotic from entering the cytoplasm Resistant populations grow from mutant bacteria through cell division Resistant populations grow from mutant bacteria through cell division

28. Useful Bacteria 1. Breakdown organic matter and recycle carbon and nitrogen 2. Help with the production and passing of food 3. Industrial chemical production (organic chemicals and fuels) 4. Clean up environmental disasters Intestinal Bacteria