Bacteria & Viruses SBI 3U

Remember - MRS. NERG Movement Reproduction Sensitivity Nutrition Excretion Respiration Growth

6 Kingdoms Archaea Eubacteria Protista Fungi Plants Animals No Viruses

Bacteria

Types of Bacteria Coccus (cocci) - Round Baccilus (baccili) – rod shaped Spirochete – corkscrew shaped Vibrios – comma shaped

Classification of Bacteria Until recently classification has done on the basis of such traits as: shape bacilli: rod-shaped cocci: spherical spirilla: curved walls ability to form spores method of energy production (glycolysis for anaerobes, cellular respiration for aerobes nutritional requirements reaction to the Gram stain. The Gram stain is named after the 19th century Danish bacteriologist who developed it. The bacterial cells are first stained with a purple dye called crystal violet. Then the preparation is treated with alcohol or acetone. This washes the stain out of gram-negative cells. To see them now requires the use of a counterstain of a different color (e.g., the pink of safranin). Bacteria that are not decolorized by the alcohol/acetone wash are gram-positive.

Viruses Viruses can’t metabolize nutrients, produce and excrete wastes, move around on their own, or even reproduce unless they are inside another organism’s cells. They aren’t even cells.

Role of viruses… “Viruses have played key roles in shaping the history of life on our planet by shuffling and redistributing genes in and among organisms and by causing diseases in animals and plants. Viruses have been the culprits in many human diseases, including smallpox, flu, AIDS, certain types of cancer, and the ever-present common cold.” http://www.microbeworld.org/microbes/virus/

When viruses come into contact with host cells, they trigger the cells to engulf them, or fuse themselves to the cell membrane so they can release their DNA into the cell.

Viruses “hijack” the cell

“Once inside a host cell, viruses take over its machinery to reproduce. Viruses override the host cell’s normal functioning with their own set of instructions that shut down production of host proteins and direct the cell to produce viral proteins to make new virus particles. http://www.microbeworld.org/microbes/virus/

Lytic Cycle Attachment Penetration Synthesis Assembly Lysis Release Mnemonic: All Pirates Sail Around Looking for Riches

All Viruses are pathogenic There are NO nice viruses……… All viruses cause disease.

Adenovirus Infections DNA Lungs, Eyes Droplets, Contact Droplets Disease Causal Agent Organs Affected Transmission / Vector Influenza RNA Respiratory Tract Droplets Adenovirus Infections DNA Lungs, Eyes Droplets, Contact Droplets Respiratory Syncytial Disease Rhinovirus Infections Upper Respiratory Tract Droplets,Contact Herpes Simplex Skin,Pharynx, Genital organs Contact Chicken pox ( Varicella) Skin, Nervous System Droplets, Contact Measles (Rubeola) Respiratory Tract, Skin German Measles ( Rubella) Skin Mumps (Epidemic Parotitis) Salivary Glands, Blood Small Pox (Variola) Skin, Blood Contact, Droplets Warts Kawasaki Disease ? Diseases Caused by Virus To Human

Mosquito ( Aedes Aegypti) Dengue Fever Blood, Muscles Hepatitis B DNA Liver Contact with body Fluids NANB Hepatitis RNA Viral Gastroenteritis Many RNA Viruses Intestine Food, Water Viral Fevers Blood Contact,arthropods Cytomegalovirus Disease Blood, Lungs Contact, Congenital transfer AIDS Retrovirus ( RNA) T-lymphocytes Rabies Brain, Spinal cord Conact with body Fluids Polio Intestine,Brain, Spinal Cord Food, Water, Contact Slow Virus Disease Prions Brain ? Arboviral Enephalitis Many RNA viruses Anthropods Yellow Fever RNA Liver, Blood Mosquito ( Aedes Aegypti) Dengue Fever Blood, Muscles Mosquito ( Aedes Aegypti ) Hepatitis A Liver Food, Water, Contact

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