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185 Cards in this Set
- Front
- Back
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What is Microbiology?
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Specialized area of biology that deals with living things ordinarily too small to be seen without magnification.
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Major groups of organisms studied in Microbiology:
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Bacteria
Viruses Fungi Protozoa Algae Heminths (parasitic worms) |
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2 basic cells cell types discussed?
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Procaryotic
Eukaryotic |
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Microorganism that lacks a cell nucleus and membrane-bound internal structures. Bacteria are made up of this cell.
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Prokaryotic cell
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a cell that has a distinct cell nucleus and other membrane-bound structures. Humans are made up of this cell.
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Eukaryotic cell.
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Father of Microbiology
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Louis Pasteur
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process of heating liquids to kill unwanted organisms.
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pasteurization
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Louis Pasteur's contributions to microbiology:
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Linked 3 different microorganisms to specific disease.
Studied diseases in silkworms and this was a significant step in the germ theory of disease. Developed vaccines; rabies vaccine |
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theory that microorganisms (germs) can invade other organisms and cause disease
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Germ theory of disease
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Studies of Pasteur and Koch along with other scientists, became known as the:
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germ theory of disease
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Koch's Postulates
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1. Specific causative agent must be found in every case of the disease.
2. The disease organism must be isolated in pure culture. 3. Inoculation of a sample of culture into a healthy animal and must produce same disease. 4. The disease organism must be recovered from the inoculated animal. |
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Joseph Lister is responsible for:
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Aseptic Technique
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Methods of handling microbial cultures, patient specimens and other sources of microbes in a way that prevents infection of the handler and others who may be exposed.
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Aseptic Technique
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Levels of Classification
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Domain
Kingdom Phylum Class Order Family Genus Species |
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formal system for organizing, classifying and naming living things
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Taxonomy
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the orderly arrangement of organisms into groups, preferable in a format that shows evolutionary relationship
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Classification
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the process of assigning names to various taxonomic rankings of each microbial species.
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Nomenclature
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the process of discovering and recording the traits of organisms so that they may be placed in an overall taxonomic scheme
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Identification
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What is Binomial Nomenclature
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Binomial (two name)
Method of assigning the scientific or specific name |
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The scientific name is always a combination of the
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genus name followed by the species name
the genus is capitalized, the species begins with lowercase letter. both are italicized |
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How is Binomial nomenclature developed:
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an international group oversees the naming of every new organism.
inspiration is extremely varied and can be imaginative some names designate the characteristics of the microbe, a location where it is found, or a disease it causes |
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Examples of Binomial nomenclature
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Staphylococcus aureus
staphule- bunch of grapes kokkus- berry aureus- golden Campylobacter jejuni kampylos- curved bakterion- little rod jejunum- section of intestine |
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developed first microscope; saw what he described as "animalcules"
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Van Leeuwenhoek
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cells found in plants and animals
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Eukaryotic cells
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Eukaryotic cells move through 3 methods (Locomotor Appendages)
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Flagella
Cilia Pseudopods |
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Have what is known as a 9+2 arrangement
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Eukaryotic Flagella
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Cross sections reveal that there are actually 9 pairs of closely attached microtubules surrounding a single pair.
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Eukaryotic Flagella
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When these microtubules slide past each other a whip-like motion occurs
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Eukaryotic Flagella
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very similar to flagella but are shorter and occur in rows over the cell surface
beat back and forth in an oar-like motion |
cilia
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amoebas use this type of motion to crawl along a surface
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Pseudopodia
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contractions of intracellular actin and myosin causes cellular extensions known as this to occur
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Pseudopodia
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composed of polysaccharides
can be network of fibers, slime layer or capsule roles include adherence to surfaces and communication between cells and protection |
Glycocalyx
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cell wall in eukaryotes are
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rigid
provide structure varied chemical compositions depending on the organism |
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Eukaryotic cell membrane differs from prokaryotic cell membrane in what ways?
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eukaryotic cells contain sterols, which provide added strength.
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lack a membrane bound nucleus
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prokaryotes
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nucleus in this cell plays an important role and acts as the control center for the cell.
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eukaryote
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structure within the nucleus form from various chromosomes and active in the synthesis of ribosomes
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Nucleolus
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DNA and proteins that make up a chromosome
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Chromatin
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when cell is not dividing it is very long, thin fibers not visible with a light microscope.
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Chromatin
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tightly coiled bodies in cells that are the primary sites of genes
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chromosome
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DNA when cell is not dividing
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Chromatin
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DNA during mitosis
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Chromosome
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proteins associated with eukaryotic DNA and serve as "winding spools" to compact and condense the chromosomes
Circular DNA |
Histone
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process of cell division
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mitosis
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microscopic series of tunnels used in transport and storage
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Endoplasmic Reticulum
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originates in the outer membrane of the nuclear envelope; involved in transport and storage. Rough texture due to ribosomes.
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Rough Endoplasmic Reticulum
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lacks ribosomes; functions in nutrient processing
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Smooth ER
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protein synthesizers
found scattered freely in cytoplasm also associated with the Rough ER |
Ribosomes
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Site in cell where proteins are modified, stored and packaged for transport.
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Golgi Apparatus
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Consists of stack of flattened, disc-shaped sacs called cisterae
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Golgi Apparatus
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Similar to ER, but does not form continuous network
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Golgi Apparatus
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Transitional vesicles that bud off of ER are picked up by the
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Golgi Apparatus
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Final step of the Golgi Apparatus after proteins are modified is to
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release or pinch off condensing vesicles
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How do the nucleas, ER and Golgi apparatus work together?
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Nucleus, the keeper of the eukaryotic genetic code, regulates all cell activities. Remains fixed and must direct activities thru structural and chemical network, which includes ribosomes (originates in nucleus) and rough endoplasmic reticulum (continuously connected w/the nuclear envelope).
DNA containing instructions to make protein, is copied into RNA and passed out to ribosomes on endoplasmic reticulum. Specific proteins are synthesized from RNA and depitised in lumen (space) of endoplasmic reticulum and then transported to Golgi apparatus, where the proteins are chemically modified and packaged into vesicles that can be used by cell in various ways (digest food, digest materials outside cell, repair cell wall and membrane) |
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Vesicle originating from the Golgi apparatus that contains enzymes involved in digestion
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Lysosome
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membrane-bound sacs containing fluids or solid particles that can be digested, secreted or stored.
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Vacuoles
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Lysosome is involved in
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phagocytosis
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method that cells use to eat
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phagocytosis
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Energy generator of the cell; extracts chemical energy from nutrients and stores it as ATP.
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mitochondria
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under microscope, they appear as round, elongated particles throughout the cytoplasm.
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Mitochondria
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consists of smooth outer membrane and inner folded membrane
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mitochondria
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folds on the inner membrane of mitochondria
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cristae
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fluid that surrounds the cristae in mitochondria
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matrix
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lots of ATP generated here
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mitochondria
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theory that suggests that mitochondria were once a prokaryotic cell engulfed by a larger prokaryotic cell; these cells worked together, formed an ancestral cell that later evolved into eukaryotic cells.
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endosymbiotic theory
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3 points of evidence that support the endosymbiotic theory
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1. Mitochondria have their own DNA
2. Mitochondria have 70S ribosomes present 3. Mit. develop independently of the cell. |
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Organelles found in algae and plant cells that are capable of converting energy of sunlight into chemical energy through photosynthesis
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Chloroplasts
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Resemble mitochondria, but are larger and contain special pigments.
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Chloroplasts
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Chloroplasts are composed of two membranes
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smooth outer membrane
folded inner membrane |
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What are the two catergories of fungus?
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Macroscopic fungi- mushrooms, puffballs, gill fungi
Microscopic fungi- molds, yeasts |
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Fungi has two cell types
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Hyphae
Yeasts |
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long, threadlike cells that make up bodies of filamentous fungi or molds
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Hyphae
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round or oval shaped cells in fungi
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yeasts
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Chloroplasts are composed of two membranes
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smooth outer membrane
folded inner membrane |
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What are the two catergories of fungus?
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Macroscopic fungi- mushrooms, puffballs, gill fungi
Microscopic fungi- molds, yeasts |
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Fungi has two cell types
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Hyphae
Yeasts |
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long, threadlike cells that make up bodies of filamentous fungi or molds
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Hyphae
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round or oval shaped cells in fungi
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yeasts
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cell division in yeast cells in which a small, new cell develops from the surface of existing cell and subsequently separates from the parent cell
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Budding
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chain of yeasts formed when buds remain attached in a row
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Pseudohypha
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woven, intertwining mass of hyphae that makes up the body or colony of a mold
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mycelium
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Hyphae are divided into sections by cross walls called
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septa
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visible growth that penetrates to digest and absorb nutrients
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Vegetative hyphae
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branch off of vegetative hyphae and produce reproductive bodies known as spores
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Reproductive Hyphae
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2 types of Asexual Mold spores
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Sporangiospores
Conida |
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enclosed in saclike head that ruptures to release spores
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Sporangiospores
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free spores not enclosed by a sac; are most common type of spores
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Conida
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3 most common types of Sexual mold spores
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Zygospores
ascospores basidiospores |
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Diploid spores form when hyphae of 2 opposite strains fuse and create a diploid zygote
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Zygospores
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the mature zygospore goes through
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meiosis and germinates
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the germinating zygospore forms a ____ that gives rise to a __________
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mycelium
sporangium |
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Haploid spores are created inside a special sac or ascus; can reproduce sexually or asexually
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Ascospores
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Fleming accidentally discovered
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penicillin
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_______ are haploid sexual spores formed on the outside of club-shaped cells known as _____
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Basidiospores
basidium |
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mushrooms reproduce asexually through
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Basidiospores
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fungal infections
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mycoses
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allergies are caused by airborne
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fungi
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2 major categories of Protists
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Algae
Protozoa |
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any unicellular or colonial organism that lacks true tissues
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Protist
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Photosynthetic organisms that include seaweeds, kelps, planktons diatoms; widespread inhabitants of marine and fresh water; also found on surface of rocks, soil and plants
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Algae
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Medical significance of overgrowth of algae
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red tide; when water is full of toxins caused by overgrowth of algae; shellfish accumulate toxins and those who eat them get food poisoning.
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huge, diverse group of single celled organisms
most contain the major eukaryotic organelles lack cell wall, so flexible cell membrane reglulates movement of food, wastes and secretions |
Protozoa
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are heterotrophic; species feed on live cells of bacteria, algae and dead plant and animal debris.
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Protozoa
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some have special feeding structures such as oral grooves and gullet that packages food into vacuoles.
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protozoa
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all protozoa have a ___ or a motile feeding stage
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trophozoite
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when conditions become unfavorable, some protozoa will enter a dormant resting stage known as a
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cyst
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rounds up during encystment and a tough, thick cuticle is secreted
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trophozoite
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asexual
mitotic cell division several reproduce within a host cell. many can also reproduce sexually |
protozoa
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Ciliates use this mode of sexual reproduction by fusing temporarily and exchanging nuclei or genetic material
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conjugation
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Unique appearance allow for identification by microschopic morphology
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Protozoa
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members include Trypanosoma (African sleeping sickness) and Giardia, an intestinal parasite; moves through flagella
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Mastigophora
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use pseudopods for movements; most are free living and not infectious
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Sarcodina (Amebas)
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movement through cilia; most have a definite mouth and feeding organelle
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Ciliophora (Ciliates)
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Motility is usually absent; complex life cycles; ex. malaria
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Sporozoa
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Only small number are pathogenic; often restricted to tropics/subtropics; many require 2 hosts to complete their life cycles
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Protozoan Pathogens
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Trypanosome species transmitted to host by a bite from a reduviid bug or "kissing bug." 11 stages of infection. Only 1% have symptoms during acute phase. No symptoms during inderminate phase.
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Chagas disease
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inflammation of the intestine; microbe that causes this disease is widely distributed in the world; does not involve multiple hosts
lives part of life cycle as a trophozoite and part as a cyst |
Infective Amebas
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Life cycle is complete when trophozoites in feces form cysts
Symtoms: gastric; lead to weight loss and dehydration in untreated can lead to organ damage; high death rate |
Amebic dysentary
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2 major groups of parasitic helminths
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Flatworms
Roundworms |
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large enough to be seen with naked eye
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Parasitic helminths
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helminths with very thin, segmented body
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flatworms
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helminths with elongated, cylindrical unsegmented body
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roundworms
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2 types of flatworms
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Cestodes
Trematodes |
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tapeworms, long ribbon-like arrangement; hermaphroditic
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Cestodes
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flukes; flat oviod bodies; jsexas are separate or hermaphroditic
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Trematodes
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elongated, cylindrical roundworms; most live in free-living soil and freshwater
smooth outer covering or cuticle are essentially headless, and taper to a fine point |
Nematodes
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multicellular with organs; main goal is to reproduce; protected by thick cuticule; mouth glands break down host's tissues.
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Helminths
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sexes are separate and different in appearance
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Nematodes
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sexes are either separate or hermaphroditic (both male and female sex organs)
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Trematodes
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roundworms that are generally hermaphroditic.
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Cestodes
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larval development occurs in secondary host
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intermediate (secondary) host
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adulthood and mating occur in the this life cycle of a helminth
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Definitive (final) host
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eggs are passed in feces, ingested by host and larvae forms in cow muscle
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tapeworm
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used as a weightloss method
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tapeworms
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don't like anesthesia and try to escape body any way possible
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tapeworms
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found in children who come into contact with eggs
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roundworm
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classified according to shape, size, degree of development of organs, presence of hooks, suckers, or other structures, mode of reproduction, kinds of hosts they infect and appearance of eggs and larvae
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helminths
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~50 species parasitize humans; distributed worldwide; billions of cases each year; 50mill infections found in N. America alone; primarily found in malnourished children
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helminths
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3 distinct parts of Flagella in Prokaryote Cell
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Filament
Hook Basal Body |
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helical structure composed of protein flagellin
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filament
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curved and tubular part of prokaryotic flagella
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Hook
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stack of rings firmly anchored through cell wall and cell membrane
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basal body
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part of flagella thar can rotate 360 degrees like a tiny propeller
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hook and filament
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Flagella of this type of cell can only undulate back and forth
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Eukaryotes
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Two general patterns of Flagella arrangement
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Polar arrangement
Peritrichous arrangement |
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flagella are attached at one or both ends of a prokaryotic cell
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Polar arrangement
includes montrichous, lophotrichous and amphitrichous |
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flagella are dispersed randomly over the surface of the prokaryotic cell
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Peritrichous arrangement
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corkscrew shaped bacteria called spirochetes have unusual wriggly form of motion, caused by 2 or more long coiled threads
create twisting or flexing motion |
Periplasmic Flagella
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small bristlelike fibers emerging from the surface of many bacterial cells and are involved in adherence to surfaces; velcro-like
involved in interactions with other cells but does not provide locomotion |
Fimbria
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tiny hollow projection used to attach bacteria to surfaces or for conjugation (transfer of DNA)
does not provide locomotion |
Pilus
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a filamentous network of carbohydrate-rich molecules that coats the cells
Protects the cell; help it adhere to its environment |
Glycocalyx
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2 forms of cell surface coating or Glycocalyx
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Slime Layer
Capsule |
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Glycocalyx that is loose shield that protects against dehydration and loss of nutrients
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Slime Layer
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Glycocalyx that is loose,gel-like covering of slime made mostly of simple polysaccharides bound more tightly than slime layer
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Capsule
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Gram-positive cell wall
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-thick, one layer
-homogenous sheath of peptidoglycan ranging from 20-80mm in thickness -No outer membrane -narrow periplasmic space - more penetratable |
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Gram-negative cell wall
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more complex; 2 major layers
-outer membrane and thinner shell of peptiidoglycan - Extensive periplasmic space -Less penetratable |
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Prokaryotic Cell membrane structure
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-just beneath cell wall; thin flexible sheet
- lipid bilayer with proteins embedded; dynamic and constantly changing -contain mostly phospholipids and proteins -contain mesosomes |
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internal folds believed to increase cell membrane surface area, participate in cell wall synthesis and guiding duplicated bacterial chromosomes into 2 daughter cells
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mesosomes
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function of cell membrane
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site for energy reactions, nutrient processing and synthesis
-regulate transport, passage of nutrients into cell and wastes out -important site for metabolic activities -enzymes & toxins secreted by membrane |
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internal structures of bacterial cell
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cytoplasm
chromosome plasmid ribosome inclusion bodies cytoskeleton |
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-dense gelatinous material
-70-80% water -mixture of nutrients (sugars, AA, organic molecules, salts) -Nutrients are "building blocks" for cell synthesis |
Cytoplasm
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-Single circular strand
-Aggregated into central area of cell -long molecule of DNA -genes that cary info required for growth and maintenance |
Chromsome
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-Nonessential piece of DNA
-separeat double-stranded circle of DNA -duplicated and passed to offsring during reproduction -not essential, but offer protection (drug resistance, produce toxins and enzymes) -important in genetic engineering |
Plasmid
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Insulin and steroids are produced through genetic engineering using ____
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Plasmids
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Made of RNA and protein
-"Factory" where protein synthesis occurs -certain antibiotics bind to 70s ribosomes which disrupts protein synthesis |
Ribosomes
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-stores nutrients, like glygocen
-aquatic bacteria have gas vesicles for buoyancy -granules- contain crystals of inorganic compounds- |
Inclusions
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-Internal network of protein polymers
-bacterial actin-helps stabilize shape -influences cell wall formation |
Cytoplasm
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small, dormant during unfavorable conditions, resistant derivative of a bacterial cell that germinates under favorable conditions into a vegetative cell;
-ordinary boiling won't kill; need pressure and heat (autoclave) to destroy; ex. anthrax, tetanus, botulism |
Endospores
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5 Bacterial shapes
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Coccus
Bacillus Spirillum Spirochete Pleomorphic |
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can be perfect spheres, or oval, bean-shaped or pointed
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Coccus
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rod-shaped, can be blocky, spindle-shaped, round-ended, long and threadlike, clubbed, drumstick
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Bacillus
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curviform or spiral shaped cylinder; rigid helix, twisted twice alone axis (like cheeto)
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Spirillum
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more flexible spiral bacteria; more twists, resembles a spring or telephone cord.
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Spirochete
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species with individual variations
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Pleomorphic
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Bacterial arrangement of Cocci:
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most varied;
pairs- diplococci groups of four- tetrads irregular clusters- staphylococci chains- streptococci complex groupings- sarcina |
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Bacterial arrangement of Bacilli
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less varied because divide only in transverse plane
-single cells -pair of cells w/ends attached-diplobaccilli -chain of cells- streptobacilli -cells of chain that remain partially attached by hinge- palisades |
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bacterial shape that is occasionally found in short chains
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Spirilla
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bacterial shape that rarely remain attached after division
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Spirochetes
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-Spiral shaped Bacteria
-rigid helix -polar flagella -cells swim by rotating around like corkscrews;do not flex -have one to several flagella -most are harmless |
Spirilla
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Spiral shaped bacteria
-flexible helix -periplasmic flagella w/in sheath -cells flex -swim by rotation or by creeping on surfaces -have 2 to 100 periplasmic flagella -syphilis and other important pathogens |
Spirochetes
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technique use in bacterial identification and classification
traits like combo of cell shape and size, gram stain reaction, acid-fast reaction and special structures (endospores, granules and capsules) |
Microscophic Morphology
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technique use in bacterial identification and classification
Appearance of colonies including texture, size, shape, pigment, speed of growth & patterns of growth in broth and gelatin media |
Macroscopic Morphology
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analogy of cell parts
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Mitochondria=Power plant
Ribosomes=manufacturing plant nucleus=command ctr/brain endopl.reticulum=Highway/transportation golgi apparatus=packaging facility protein=packages cell membrane=protective fence, or barrier enclosing the facility lysosomes=waste disposal plant |
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Describe the Life Cycle of a Pinworm
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1. Person, often a child, swallows eggs picked up from another infected person by direct contact or touching contaminated surface
2. Eggs hatch in intestine and release larvae that mature into adult worms w/in 1 month 3. Worms mate and female migrates out the anus to deposit eggs, which cause intense itching. 4. Scratching contaminates fignres, which transfer eggs to bedclothes and other objects. Person becomes host and can spread to others and reinfect themself. |
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Describe Protozoan Life Cycle (Amebic Dysentary)
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1. Cysts are eaten
2. In small intestine, cyst germinates into a large amoeba that divides to form small amoebas (the trophozoite stage) 3. The trophozoites invade the large intestinal wall, begin to feed and grow and penetrate liver, lungs and skin. Cause GI problems, weight loss and dehydration. 4. Mature cysts are released into feces and may be spread through contaminated food and water. |
