Bacteria & Viruses

1. Bacteria & Viruses

2. Microbiology • Is the basic science that explores microscopic organisms including viruses, bacteria, protozoa, parasites, and some fungi and algae. • The organism lack tissue differentiation and are unicellular, and exhibit diversity of form and size.

3. Characteristics of Organisms • All living things are composed of cells • All living things perform certain chemical processes such as growth and digestion • All living things can reproduce • All living things either make their own nutrients or ingest nutrients from the environment • All living things respond to stimuli such as light and touch

4. Viruses, bacteria, fungi, and parasites may infect the human body and interfere with normal body functions.

5. What are Viruses? • A virus is a non-cellular particle made up of genetic material and protein that can invade living cells and reproduce. • A person can catch a cold many times because there are many varieties of cold virus that cause similar symptoms

6. Viruses • Are not considered to be alive but they affect living things. • With the ability to reproduce, viruses lack nearly every characteristic of life • Need a host cell • Not composed of cells • Do not respond to stimuli • Do not use energy for growth and development • Need electron microscope to see

7. Types of Viruses • AIDS • Lyme disease • Bacterial meningitis • Leprosy

8. Disease • Any change that disrupts the normal function of one or more body systems. • Noninfectious diseases: Diseases caused by exposure to certain chemicals or traits that are inherited. • Infectious diseases: Diseases caused by a pathogen(any microbe that causes disease.)

9. Diseases Caused by Viruses • Cause disease by either damaging or killing cells • First attaches itself to a healthy cell and then injects its DNA or RNA into cell • Then replicates once inside infected cell • No Cure, just prevention with vaccine. • Vaccines: a substance introduced into the body to stimulate the production of chemicals that destroy specific viruses or bacteria..

10. How Infectious Disease Spread • Infectious disease can be spread through: 1. contact with an infected person ex: Influenza (V) 2. contact with a contaminated object ex: Athleteis foot (F) or Influenza (V) 3. contact with an infected animal ex: Lyme Disease (B): Bite from infected tick contact with an environmental source.

11. Bacteria • Are small organims constiting of one cell that lack chlorophyll • Except for viruses they are the smallest living things on earth • Bacteira are found everywhere, in the air, soil. Water, and inside of your body and skin. • They multipy very rapidly and from colonies of millions or even billions witin a space as small as a drop of water. • Classified 4 ways (spherical, rodlike, spiral, or corkscrew.

12. Diseases Caused by Bacteria • Use antibiotics to cure bacterial infections • Antibiotics or a chemical that can kill bacteria without harming a person’s cell • Bacteria can develop a resistance to antibiotic and will no longer kill • This is what happens when you do not take medicine completely

13. Vectors help spread disease • Are mechnaims (other then people) that spread disease without getting itself sick. • Rats, ticks, mosquitios, and soil are examples. • An infectious disease is one that can be passed from one

14. Diseases Causes by Protists • the protists that cause each of these diseases are caused by parasites • Parasite is an organism that takes nourishment or habitat from another organism • Most cases do not kill the host • Examples • Dysentery • Malaria *

15. Epidemic • Is an outbreak of a disease that affects a disproportionately large number of individuals within a population, community, or region at the same time

16. Pandemic • Is an epidemic of an infectious disease that is spreading through human populations across a large region, continent,, or even worldwide.