Spontaneous Generation
Living things came from non-living entities (rats from old clothes, worms from rotten meat)
Germ Theory
Stated that living things came from other living things and that germs (animalcules) can invide other organisms and produce disease.
Leewenhoek
Invented the microscope (300x magnification)
Animalcules
Name Leewenhoek gave the microbes he discovered under his microscope
Pasteur
Developed pasteurization for beer and wine
Developed first effective vaccine against rabies
Koch
Demonstrated that anthrax in humans/cattle is due to Bacillus anthracis
First to isolate bacteria in pure culture
Developed artificial nutrient medium containing agar
Koch's Postulates-steps necessary to prove that an organism is the true cause of a disease
Semmelweiss
First to implement sanitary practices in maternity wards to avoid puerperal fever
Lister
Developed procedures for surgical antisepsis by using carbolic acid to disinfect
Ehrlick
Initiated search for "magic bullets" or chemicals that target pathogens but spare host tissues. Father of Chemotheraphy
Flemming
Discovered penicillin (first antibiotic)
Major Groups of Microbes
Bacteria, Protists, Algae, Protozoa, Fungi
Bacteria
Unicellular prokaryotes, divide by binary fission,
Can be photo or non-photo synthetic, motile, non-motile (naturally aerobic but can switch to anaerobic mode when oxygen is absent)
Shapes: Coccus, bacillus, spirillum, star, square, filamentous, pleomorphic
Protists
Mostly unicellular eukaryotes
Algae
plant like protest that are usually aquatic and photosynthetic.
Protozoa
animal-like protists, mostly capable of movement (amoeba)
Fungi
mostly multi-cellular eukaryotes with filamentous bodies, usually spore-bearing, generally non-motile, non-photosynthetic although may look like plants in appearance
yeasts = unicellular
molds = multicellular mushrooms
Viruses
Submicroscopic, acellular entities composed of nucleic acid (DNA or RNA, but not both) with a protein coat, and always obligate parasites.
Other Microbes
Helminths, Arthropods
Importance of Microbes to Man and Ecosystem
Serve as agents of human, plant and animal diseases
Microbes are decomposers and cleaners of the environment
Microbes form a symbiotic relationship with other organisms and are crucial to the survival of those micro-organisms
Importance of Microbes
Consumed as food by other organisms
Used in production of food and beverages
Sources of antibiotics and other pharmaceutical products
Excellent tools for research
Bubonic Plague
Killed 25 million Europeans
Yersinia pestis
Lasted 300 years
Typhus
caused by bacterium rickettsia species
smallpox
caused worldwide death and migration of people
Influenza
more soldiers died from this than warfare.
Cholera
vibrio cholera--one of the main causes of death in the 3rd world due to polluted water
AIDS
One of the most cruel microbial diseases
SARS
(corona virus) Severe Acute Respiratory Syndrome,
affected china in 2003-2004
Mad Cow Disease
Infectious Disease = prions
What microbe is penicillin made from?
Fungus
What microbe is streptomycin made from?
Bacteria
What microbe is Botox made from?
bacterium
Why are microbes excellent tools for research?
The have simple structures that are easy to study
Fast growth rate gets results in a short period of time
They can be mass produced at a reasonable cost
What is the name for the branch of microbiology studying bacteria?
Bacteriology
What is the name for the branch of microbiology studying fungi?
Mycology
What is the name for the branch of microbiology studying algae?
Phycology
What is the name for the branch of microbiology studying parasites?
parasitology
What is the name for the branch of microbiology studying viruses?
virology
What is the name of the branch of biology studying protists?
Protozoology
Do prokaryotes have a nucleus?
No
How many cells do prokaryotes have?
One. They are single-celled
What is the cell wall of a prokaryote made of?
Peptidoglycan
Cell size of a prokaryote: small or large?
Small (0.3-10um)
Do prokaryotes have mitochondria?
No
Protists, Fungi, Plants, Animals are examples of _______.
Eukaryotes
Do eukaryotes have a nucleus?
Yes
What is the cellular structure of a Eukaryote?
Mostly multicellular except protists and yeasts
What is the general cell size of a Eukaryote?
Large (1-100um)
What is the cell wall made of in a Eukaryote?
Cellulose, chitin (none in animals)
What is the function of a cell membrane in a prokaryotic cell?
Double layer of phospholipid, making it semi-permeable
Proteins aid in transport
Lipids maintain the fluidity of membranes
What are the two unique functions of prokaryotic cells?
Site of DNA attachment during replication
Site of Respiration (ATP production)
Endospores contain many layers of which two substances?
calcium and dipicolonic acid
Endospores are considered to be survival rather than reproductive structure because ____________.
They can withstand adverse environmental conditions.
Endospores are formed by only some bacteria of the genus _________ and _____________.
Bacillus and Clostridium
Cell walls with a gram positive reaction will have a thick ______________ layer.
Peptidoglycan layer
Cell walls with a thin peptidoglycan layer will be be Gram ______________.
negative
Acid-fast cell walls will have both a peptidoglycan layer, as well as a thick layer of lipid. True or False?
True
Members of the Kingdom Prokaryotae (Monera) are _______________ and ______________.
Archaea and Bacteria
Prokarayotes without peptidoglycan in their cell walls, surviving in extreme environmental conditions and not inhibited by antibiotics are _____________.
Archaea
Archaea that are strict anaeorobes, decompose in sewer systems and produce methane gas are _________.
Methanogens
Archaea that thrive in high salt environments. Some are photosynthetic with purple pigment.
Extreme Halophiles
Archaea that survive in very hot environments (60-80 degrees C) such as volcanic vents, mud springs, hot springs. Some can produce sulfuric acid.
Extreme Thermophiles
Prokaryotes with typical peptidoglycan in their cell walls, survive in ordinary environments, mostly inhibited by antibiotics.
Bacteria
Type of bacteria without cell walls, fastidious and hard to grow in artificial medium.
Mycoplasmas
Obligate parasites, can't grow on artificial medium, thought to be viruses.
Chlamydia, and Rickettsiae
Only true bacteria without peptidoglycan
Chlamydia
Mostly unicellular eukaryotes, "Dumpsite" for organisms that cannot be classified as plants, animal, or fungi. Subdivided into "phylum" based on mode of locomotion.
Kingdom Protista
An "animal-like" protist
Protozoa
Move by pseudopodia (false feet), which are actually cytoplasmic extensions
Sarcodina (Amoeba)
Motile by one or more flagella, some are free-living but others are pathogenic
Mastigophora
Animal-like protist. Non-motile, parasitic protozoa with complex life cycle involving a biological vector or carrier.
Sporozoans
Animal-like protist. Move by cilia over the cell, largest group of protozoa that are involved in cleaning the environment
Ciliates (Paramecium)
Plant like protists capable of photosynthesis
Algae
Plant like protist. Motile by single flagellum and has characteristic pigmented "eyespot" as light detector.
Euglenoids
Plant like protist. Non-motile with glass like appearance due to silica in the cell walls, used as an abrasives in toothpaste.
Diatoms.
What is a cell?
Basic unit of life. All organisms are made up of at least one cell.
What are the four universal components of cells?
1. Cytoplasm (Semi-solid part of the cell)
2. Plasma membrane (Cell membrane)
3. DNA (Genetic material)
4. Ribosome (Site of protein synthesis)
Long, spiral bacteria (some are agents of STD's such as syphilis and lime disease)
Spirochetes
Kingdom made up of mostly multicellular, filamentous, spore-bearing, non-photosynthetic. Classification within the Kingdom is based on their sexual structures.
Kingdom Fungi
Member of Kingdom Fungi, sexual spores can survive under adverse environment.
Includes many molds that can cause food spoilage and may produce carcinogens
Zygomycetes (molds)
Member of Kingdon Fungi, sexual spores are borne in a club-like structure. Many are edible mushrooms.
Basidomycetes (club-fungi)
Member of Kingdom Fungi, produces hallucigenic (LSD-like) and toxic substance called "muscarin".
Amanita muscaria
Sac-like fungi, sexual spores are born in a sac-life structure. 8 spores in a sac (like a pea pod)
Asomycete
"Fungi imperfecti", sexual stage has not been found
Deuteromycetes
B-A-D-Z
Pneumonic for remembering Kingdom Fungi:
B-Basidomycetes
A-Asomycetes
D-euteromycetes
Z-Zygomycetes
Eukaryotic cells divide by __________.
Mitosis
Prokaryotic cells divide by __________.
Binary Fission
What are the four stages of mitosis?
Prophase, Metaphasse, Anaphase, Telaphase
What triggers sporulation?
Exhaustion of Nutrients
Accumulation of Toxic Metabolites
Drought
High Temp or pH
What are the four phases of the bacterial growth curve?
Lag, Log, Stationary, and Death phases
What happens in the lag phase of the bacterial growth curve?
Period of Adaptation, no significant increase in population, cells increase in size.
What happens in the log phase of the bacterial growth curve?
Period of exponential growth, most active metabolically, antibiotics will have the greatest effect
What happens in the stationary phase of the bacterial growth curve?
Period where the number of live cells = number of dead cells, space is limited, endospores begin to form
What happens in the death and decline phase of the bacterial growth curve?
Cells lose ability to divide, # of dead cells increases, endosporers are more abundant than cells.
Mechanism of Gene transfer in bacteria where a small piece of "naked DNA" from the environment is taken in by bacteria cell. Only occurs at certain stage of growth, plasmid, and parts of chromosomes from dead cells can get into host cell.
Transformation
Mechanism of gene transfer where DNA is transferred from a bacteriophage (virus that infects bacteria) to a bacterial cell
Transduction
Mechanism of gene transfer where direct transfer of DNA via F-Pilus, occurs usually between 2 related bacteria, but unrelated can mate.
Conjugation
Biosynthetic pathways. Large molecules are built from small building blocks. (Ie. dehydration synthesis)
Anabolic Pathways
Endorgonic requires ___________________.
Energy Input, chemical bonds are created.
Degradative pathways, large molecules are broken down to simpler ones
Catabolic pathways
Exorgonic= _______________________.
Energy is released, chemical bonds are broken.
Speed up chemical reactions without being used up in the process
Enzymes
Enzymes are usually named after their _____________.
substrates
Enzyme names end with "______"
"ase"
Specific molecular shape where the substrate "fits" into the enzyme due to a specific molecular shape.
"lock and key"
Extreme temperature, pH, ionic concentration are all factures in __________________.
Denaturation of an enzyme
Binding to active sites of enzymes, depriving substrates of their binding sites
Competitive Inhibition
Binding to other sites (other than the active site) thus deforming the shape of the active site is called _______________.
Non-competitive inhibition