A. General Info 1. A non-living segment of nucleic acids (either RNA or DNA) contained in a protein coat (called the capsid). 2. smaller than prokaryotes. 3. Reproduce by invading living cells a. Lytic Cycle b. Lysogenic Cycle

B. Viral Structure 1. Viruses exist in a variety of shapes. 2. They can be helical, rodlike, or polyhedral. 3. Others have their capsid surrounded by an envelope. a. The envelope is made of proteins, lipids, and glycoproteins. 4. Some viruses specifically infect bacteria. They are called bacteriophages

C. Viral Infections 1. Lytic infections a. virus enters bacterial cell b. Makes copies of the viral DNA c. Makes viral capsid proteins d. assembles new virus particles e. Causes the cell to burst or lyse f. example: bacteriophage T4

2. Lysogenic Cycle a. viral nucleic acid is inserted b. Viral nucleic acid is copied & multiplies c. each new generation of daughter cells that comes from the original host cell is infected d. the bacteriophage DNA that becomes a part of the host’s DNA is called a prophage

D. RNA viruses 1. Common Cold a. Called a rhinovirus b. very fast acting c. capsid settle on a cell (nose) & get absorbed by the cell d. the cells makes the viral RNA and translates it into the viral protein e. Within 8 hours there are 100’s of new virus particles in the body

2. HIV- human immunodeficiency virus a. causes the fatal disease Acquired immune deficiency syndrome (AIDS) b. belongs to a group of viruses called retroviruses - genetic info is copied from RNA to DNA c. When it infects a cell it inserts the viral DNA into the hosts DNA d. similar to a lysogenic infection in bacteria e. The virus will remain inactive for a long time before it damages the host’s immune system

E. Viral Disease 1. Viruses are pathogens-agents that can cause disease, 2. The most lethal virus in human history may be the influenza virus a.k.a. the flu 3. Emerging viruses are newly recognized viruses or viruses that have reappeared. a. They are pathogenic to humans and usually evolve in remote areas. b. Examples of emerging viruses include West Nile Virus and the hantavirus.

Common Cold ›Sneezing, sore throat, fever, headache, muscle aches ›Contact with contaminated objects, droplet inhalation Influenza ›Body aches, fever, sore throat, headache, dry cough, nasal congestion ›Flu viruses spread in respiratory droplets

AIDS ›Helper T cells are destroyed ›Contact with contaminated bodily fluids Chicken Pox ›Skin rash of blister like lesions ›viruses spread in respiratory droplets, highly contagious Hepatitis B ›Jaundice, fatigue, abdominal pain, nausea, vomiting, joint pain › Contact with contaminated bodily fluids

West Nile ›Fever, fatigue, body ache ›Bite from an infected mosquito Human Papillomavirus (HPV) ›Genital or anal warts, cancer of cervix, anus & penis ›Sexual contact

A. Characteristics of Prokaryotes 1. single-celled organisms that lack internal membrane-bound organelles 2. No nucleus 3. Example: Bacteria

B. Types of Bacteria 1. Eubacteria- ch. 18 notes 2. Archaebacteria - ch. 18 notes 3. Cyanobacteria a. (a type of Eubacteria) are photosynthetic bacteria b. released oxygen gas into the earth’s oceans & atmosphere c. This allowed life to move to land

C. Bacterial Structure 1. Internal compartmentalization: Bacteria do not have a nucleus and have no internal compartments 2. Cell Size: Bacteria are generally much smaller than eukaryotes 3. All bacterial are unicellular 4. Chromosomes: Bacterial chromosome consists of a single circular piece of DNA

5. Reproduction: Bacteria reproduce by binary fission 6. Flagella- movement 7. Metabolic Diversity: Bacteria perform many metabolic activities that eukaryotes lack

8. Extra features › Capsule › 2 types of cell walls: Gram negative or Gram positive › Endospores › Pili

CAPSULE Dental Plaque is caused by the bacteria Streptococcus mutans.

Gram Stain- used to I.D. bacteria

D. Reproduction 1. Copy their DNA all the time 2. Uses a process called binary fission 3. A bacterial cell can copy itself every 20 minutes 4. Bacterial cells can have genetic variation through transformation or conjugation a. Transformation: taking in foreign DNA and incorporation it into the bacterial genome b. Conjugation: joining with another bacterial cell and exchanging DNA though the pili

E. Bacteria shapes and arrangements 1. Bacillus-rod-shape 2. Coccus-round-shaped 3. Spirillum-spiral shaped 4. arranged into strands- ‘strepto’ 5. form clusters have the prefix ‘staphylo’

F. Functions of Prokaryotes 1. Chemical Recycling a. Breaks down or decomposes organic waste products in the environment b. Part of the carbon cycle and the nitrogen cycle c. Bacteria can be detrivores

2. Human Uses a. Bioremediation: using bacteria to remove pollutants from sewage water, soil and air b. Cleaning up oil spills c. Extract lead and mercury run off from mines d. Make vitamins and antibiotics e. Make food (cheese, yogurt, pickles, wine) abc-news/more-mere-magic-mushrooms html

G. Pathogenic Bacteria: 1. cause disease by either living off of the host, or by secreting toxins 2. Toxins can be produced by bacteria that grow on food, like botulism and E. coli. 3. Many bacterial infections can be treated by antibiotics, proper food preparation, and cleanliness. 4. remember to not overuse antibiotics!!! 5. Biowarfare is the deliberate exposure of people to biological toxins or pathogens such as bacteria or viruses.

1. Lyme Disease ›“bull's-eye” rash at site of tick bite, fever, fatigue, headache ›Ticks transmit Borrelia burgdorferi 2. Tetanus ›Lockjaw, stiffness in neck & abdomen, difficulty swallowing, high blood pressure, muscle spasms ›Bacteria enter body through a break in the skin

3. Tuberculosis ›Fatigue, weight loss, fever, night sweats, chills, appetite loss, bloody sputum from lungs ›Bacteria are inhaled 4. Bacterial Meningitis ›High fever, headache, stiff neck, nausea & fatigue ›Bacteria are spread in respiratory droplets by coughing & sneezing

5. Strep throat ›Fever, sore throat, headache, fatigue ›Direct contact with mucus from an infected person