Microbiology
The study of microorganisms, or small cells, that carry out one or more life processes and are typically too small to be seen by the naked eye
Four Life Processes
Ability to replicate, grow, metabolize and respond to the environment
Seven Major Types of Microbes
Protozoa, Algae, Bacteria, Archaea, Fungi, Helminths and Viruses
Bacteria
Small, simple, single celled organisms that have prokaryotic cell structure. Most have peptidoglycan cells walls, while few lack any cell wall
Prokaryotic Cell
simple cells that lack a cell membrane around their genetic information and lack membrane-bound organelles in the cytoplasm. They are typically smaller that Eukaryotic cells.
Archaea
Small, simple, single celled organisms that have a prokaryotic cell structure.
Similarity to bacteria
shape and size
Difference to bacteria
differ from bacteria in ribosomal structure, cytoplasmic membrane structure and cell wall structure. They do not have peptidoglycan cell walls.
Two major groups
Methanogens- obligate anaerobes that produce methane gas
Extremophiles- live under extreme conditions of temperature, pH or salinity
Fungi
unicellular or multicellular organisms that have eukaryotic cell structure, cells walls composed of cellulose or chitin, a plant-like absorptive metabolism, require an organic source of carbon and do not carry out photosynthesis
Types of Fungi
mushrooms, yeasts, molds
Historical Definition of Protozoa
unicellular organisms that have eukaryotic cell structure, lack cell walls, require an organic source of carbon and do not carry out photosynthesis
Why is the definition of Protozoa no longer valid?
Some organisms previously classified as algae have been reclassified as protozoa, so the historical definition is no longer valid
Algae
Unicellular and multicellular organisms that have a eukaryotic cell structure, carry out photosynthesis, have cell walls compose of a polysaccharide and other substances
What is essential to be classified as algae?
Must be able to carry out photosynthesis
Helminths
Invertebrate worms or multicellular eukaryotes that lack cell walls
Why are Helminths study in Microbiology?
Some species are common parasites of humans and animals and their life cycle includes microscopic forms.
Elephantiasis
A disease caused by Helminths which causes the lymphatic system to stop working properly, resulting in fluid build up. This is transmitted by mosquitos
Schitosomiasis
A disease caused by Helminths which causes blood vessels to be blocked from the liver which leads to fluid build up in the stomach
Viruses
Small acellular particles that are too small to be seen with a light microscope. They are also obligate intracellular parasites that can replicate themselves only by infecting a living host cell.
What are viruses made of?
Nucleic acids, a protein coat and sometimes a membrane coat
Bacteriophages
Viruses that infect bacteria
HIV
Virus that infects human T cells causing AIDS
Ebola
Virus that causes the ebola hemorrhagic fever, a deadly disease.