Microbes and Diseases

(don’t write) All bacteria, some protists, and fungi are unicellular organisms. Together, these tiny organisms are called microbes.

Characteristics of Living Things All living things are composed of cells. All living things perform certain chemical processes such as growth and digestion. All living things 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.

Disease A disease is any change that disrupts the normal function of one or more body systems. – Some diseases are caused by expose to certain chemicals in the environment. – Other diseases are caused by traits that are inherited. – Many disease are caused by pathogens, microbes that cause a disease.

Disease Noninfectious Disease – not spread from one organisms to another Infectious Disease – disease caused by a pathogen

Viruses A virus is a particle that consists of a nucleic acid enclosed within a protein shell that requires a living cell in order to reproduce. Viruses lack nearly all characteristics of life. The shape of a virus is determined by the arrangement of the proteins in its capsid. (Capsid is the protective shell around the virus cell.)

Diseases caused by VIRUSES Viruses cause disease by either damaging or killing cells. A virus attaches to a healthy cell and then injects DNA or RNA into the cell. A mutagen is anything that changes the DNA of an organism. A virus can be a mutagen because it inserts its own genes into the cell’s DNA.

Diseases caused by VIRUSES Flu Polio Smallpox Yellow Fever Measles AIDS Some types of cancer are caused by viruses. For example, cervical cancer is associated with exposure to the human papilloma virus (HPV)

Bacteria Bacteria are commonly referred to as prokaryotes (no nucleus). Bacteria are organisms. Bacteria are named after their shapes. Draw: CoccusBacillusSpirillum

Classifying Bacteria Bacteria are classified into 2 kingdoms – Archaebacteria (can survive without oxygen) – Eubacteria (ancient prokaryotes)

Diseases caused by BACTERIA Many diseases caused by bacteria have been brought under control with the help of antibiotics. Antibiotic Resistant – Bacteria that have developed a resistance are no longer killed by antibiotics.

Disease caused by BACTERIA Food poisoning Leprosy Lyme disease Stomach ulcers Pneumonia Tuberculosis Typhoid fever

Protists and Fungi Protists are eukaryotes (have nucleus and membrane bound organelles) Kingdom Fungi includes both single-celled and multi-celled organisms. Fungi are not able to make their own food.

Protists and Fungi Some fungi act as decomposers. – Decomposers digest matter in the environment and then take the matter they use as food into their own cells Other fungi act as parasites. – Parasites feed on the body fluids and tissues of other organisms.

Diseases caused by MICROBES List 4 facts about each of the following diseases on the LEFT side of your notebook. Malaria Giardiasis African Trypanosomiasis Amoebiasis