I NFECTIOUS D ISEASES #1 Pathogens

T HE COLD AND F LU SEASON IS HERE

Please cover your mouth

Can be a prion, viroid, virus, bacteria, protozoan eukaryotics cells 10, ,000 nm bacteria cells ,000 nm viruses nm viroids nm prion 2-10 nm 1 nanometer (nm) = one billionth of a meter 100 nm

a. How they cause harm: Some are benign, but many harm their host organism by destroying or altering its cell structure. b. How the body combats them: Generally the body perceives viruses as antigens and produces antibodies to counteract the virus. c,. How doctors combat them: They can’t. Antibiotics DON’’T work! d. Replication: Lytic cycle – destroys the host cell in replication Lysogenic Cycle – host cells not immediately destroyed. Virus A non-living pathogen made of DNA or RNA and a protein coat. Can infect many organisms. RNA or DNA Capsid (protein coat) Lysogenic Cycle

a. How they cause harm: Attacking cells Making toxins that get carried by blood to sites throughout the body. b. How the body combats them: Bacteria and their toxins are perceived as antigens by the body, which in turn produces antibodies. c. How doctors combat them: Antiseptics – Kill bacteria. Antibiotics – Stop bacteria from replicating. d. Replication: Asexual replication Bacteria Cell wall DNA Cell membrance

BacillusCoccusSpiral Bacteria commonly come in three forms Bacillus anthracis Anthrax Staphylococcus Food Poisoning Treponema pallidum Syphilis