Chapters 1 & 4 Flashcards
Coccus
Possible shape of a bacterial cell. Plural: cocci; berry-shaped
Bacillus
Possible shape of a bacterial cell. Plural: bacilli; little rods or walking sticks
Spiral
Possible shape of a bacterial cell
Diplococci
Cocci that remain in pairs after dividing
Streptococci
Cocci that divide and remain attached in chainlike patterns
Tetrads
Bacterial shape; Bacterial cells that divide in two planes and remain in groups of four
Sarcinae
Bacteria cell shape; Those that divide in three planes and remain attached in cublike groups of eight
Single bacilli: single rod like bacteria cell
Diplobacilli
Vibrios
Bacteria cells that look like curved rods
Spirilla
Singular: Spirillum
Spirochetes
Group of spiral shaped bacteria cells
Monomorphic
In relation to bacteria, this means that the cell maintains a single shape. Generally true unless there are environmental factors that cause their shapes to alter. If the shape is altered the identification becomes difficult. Some bacteria cells are genetically pleomorphic which means they can have many shapes, not just one.
Pleomorphic
Bacteria that cells are genetically pleomorphic, which means they can have many shapes, not just one.
Glycocalyx
General term for substances that surround cells; Bacterial glycocalyx is a viscous (sticky), gelatinous polymer that is external to the cell wall and composed of polysaccharide, polypeptide, or both. Varied composition throughout species, but mostly secretes from the cell to the cell surface. If the substance is organized and firmly attached to the cell wall the glycocalyx is described as a capsule. Presence of a capsule is determined by negative staining. If the substance is unorganized and only loosely attached to the cell wall the glycolayx is described as a slime layer.
Extracellular Polymeric Substances (EPS)
The glycocalyx is a very important component of biofilms. A glycocalyx that helps cells in a biofilm attached to their target environment and to each other. It protects the cells within it, facillitates communication aomong them, and enables the cells to survive by attaching to various surfaces in their natural environment.
Flagella
Not to be confused with phalanges which can overturn a commercial airplane’s engine (Source: Phoebe Buffet). Flagella are long filamentous appendages that propel bacteria.
Atrichous/Peritrichous/Polar/Monotrichous/Lophotrichous/Amphitrichous
Different possibilities for Flagella locations on bacterial cell.
Atrichous: No flagella
Peritrichouse: All over flagella
Monotrichous: One flagella at one end
Lophotrichous: tuft of flagella at one end
Amphitrichous: One larger flagella at each end
Three basic parts of flagella
- Filament: the long outermost region, constant in diameter and contains the globular; contains protein flagellin arranged in several chains that intertwine and form a helix around a hollow core
- Basal body: Anchors the flagellum to the cell wall and plasma menbrane; composed of small central rod inserted into a series of rings. Gram-negative bacteria contain two pairs of rings; the outer pair of rings is anchored to various portions of the cell wall and the inner pair of rings is anchored to the plasma membrane. In gram-positive bacteria only the inner pair is present.
- The hook at which the flagella attaches to the bacteria cell
Motility
The ability of a cell/organism to move by itself; helped by flagella
Taxis
Benefit of flagella is that bacteria is able to move toward a favorable environment or away from a particular stimulus; this movement is called taxis.
Chemotaxis: In response to chemical stimuli from the falgella a bacteria cell can determine if the chemotactic signal is positive (called an attractant) the bacteria move toward the stimulus; if negative (called a repellent) the bacteria move away
Phototaxis: a bacteria’s movement away from light stimuli
Axial Filaments
Given spriochetes particular spiral, intertwined cells, they move by the means of axial filaments (also called endoflagella) which are bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around the cell
https://vimeo.com/53465803
Fimbriae
Singular: fimbria;
Subtype of pilin, a protein arranged helically in shorter lengths compared to flagella on the outside of a bacterial cell. Can occur at the poles or be evenly distributed across the cell. Fimbriae have a tendency to stick to each other and to surfaces - as a result they are involved in forming biofilms and other aggregations on the surfaces of liquids, glass, and rocks. Fimbriae help attach bacteria cells to epithelial surfaces in the body
Pili
Subtype of pilin, a protein arranged helically in shorter lengths compared to flagella on the outside of a bacterial cell.
Usually longer than fimbriae; involved in motility and DNA transfer. One type of motility, twitching, a pilus extends by the addition of subunits of pilin, makes contact with a surface or another cell, and then retracts (power-stroke) results in short jerky intermittent movements.
Another type of motility associated with pili is gliding motility which is the smooth gliding movement of myxobacteria, some utilize pilis retraction.
Conjugation pili: pili used to bring bacteria together allowing the transfer of DNA from one cell to another. This can include a bacteria cell with or without the same DNA makeup. In this process one bacterium called an F+ cell connects to receptors on the surface of another bacterium of its own species or a different species. The F+ cell is added to the other cell and the exchanged DNA can add a new function to the recipient cell, such as antibiotic resistance or the agility to digest its medium more efficiently
Cell Wall
A complex, semirigid structure responsible for the shape of the cell. Almost all prokaryotes have a cell wall that surrounds the underlying, fragile plasma (cytoplasmic) membrane and it protects it and the interior of the cell from adverse changes in the outside environment
Major function: prevent bacterial cells from rupturing when the water pressure inside the cell is greater than that outside the cell ; Helps maintain shape of bacterium and serves as a point of anchorage for flagella.
It should be noted that the cells of some eukaryotes, ncluding plants, algae, and fungi, have cell walls, their walls differ chemically from those prokaryotes, are simpler in structure, and are less rigid
Peptidoglycan
Macromolecular network that composes a bacterial wall; present alone or with other substances. Consists of a repeating disaccharide connected by polypeptides to form a lattice that surrounds and protects the entire cell. Made up of disaccharides which are made up of NAG and NAM that line up in chains and are connected to polypeptides ; structure of polypeptide link varies but always include tetrapeptide side chains;
Penicillin interferes with the final linking of the peptidoglycan rows by peptide cross-bridges. resulting in the cell wall becoming greatly weakened and the cell undergoes lysis (destruction caused by rupture of the plasma memrane and the loss of cytoplasm)
Microorganisms
Organisms that are too small to be seen with the unaided eye; includes bacteria, archaea, fungi, protozoa, microscopic algae, and viruses
Benefits of microbes in our lives
- Decompose organic waste
- Generate oxygen by photosynthesis
- Produce chemical products such as ethanol, acetone, and vitamins
- Produce products used in manufacturing (e.g. cellulase) and disease treatment (e.g. insulin)
How many microorganisms are pathogenic?
Only a small portion
Knowledge of microorganisms allows humans to…
- Prevent food spoilage
- Prevent disease
- Understand causes and transmission of disease to prevent epidemics
Who established the system of nomenclature? What year?
Carolus Linnaeus; 1735
What are the two names included in each organism;s nomenclature?
The genus and the specific epithet (species)
Scientific names are _______ when writing and _______ when typing. The roots are _______ and maybe be descriptive or honor a scientist.
underlined; italicized; latin
Who discovered E. coli? What does the bacteria’s name mean?
Theodor Escherich; describes the bacterium’s habitat - the large intestine, or colon
Explain the name Staphylococcus
-Describes the clustered (staphylo-) spherical (coccus) cells
Name the different types of organisms
Bacteria
Archaea
Fungi
Algae
Viruses
Multicellular Animal Parasites: flatworm/roundworm
Characteristics of Bacteria
- Prokaryotes
- Single-celled
- Peptidoglycan cell walls
- divide via binary fission
- derive nutrition from organic or inorganic chemicals or photosynthesis
Characteristics of Archaea
- Prokaryotes
- Lack of peptidoglycan cell walls
- Often live in extreme environments
- Include:
- mehtanogens
- extreme halophiles
- extreme thermophiles
Characteristics of Fungi
- Eukaryotes
- Distinct nucleus
- Chitin cell walls
- Absorb organic chemicals for energy
- Reproduce sexually or asexually
- Yeasts are unicellular
- Molds and mushrooms are multicellular
- Molds consist of masses of mycelia, which are composed of filaments called hyphae
Characteristics of Protozoa
- Unicellular eukaryotes
- Absorb or ingest organic chemicals
- May be motile via pseudopods, cilia, or flagella
- Free-living or parasitic (derive nutrients from a living host)
Characteristics of Algae
- Eukaryotes
- Cellulose cell walls
- Found in freshwater, altwater, and soil
- Use photosynthesis for energy
- Sexual and asexual reproduction
- Produce oxygen and carbohydrates
Characteristics of Viruses
- Acellular
- Consist of DNA or RNA core
- Core is surrounded by a protein coat
- Coat may be enclosed in a lipid envelope
- Are replicated only when they are in a lviing host cell
- Inert outside living hosts
Characteristics of Multicellular Animal Parasites
- Eukaryotes
- Multicellular animals
- Not strictly microorganisms
- Parasitic flatworms and roundworms are called helminths
- Some microscopic stages in their life cycles
What is Cell Theory and who disovered it?
All living things are composed of cells; discovered by Robert Hooke in 1665 when he reported all living things are made of tiny boxes
Spontaneous generation
The hypothesis that life arises from nonliving matter; a “vital force” is necessary for life
Biogenesis
The hypothesis that living cells arise only from pre-existing living cells
Who demonstrated that microorganisms are present in the air
Louis Pasteur
If nutrient broth is plased in a flask, heated, without a seal… what will happen?
There will be microbial growth
If nutrient broth is placed in a flask, heated, and then immediately sealed, what happens?
There is no microbial growth
Pasteur showed that microbes are responsible for _______.
Fermentation
What is fermentation?
the microbial conversion of sugar to alcohol in the absence of air
_________ is responsible for spoilage of food and beverages
Microbial growth
________ that use air spoil wine by turning it into vinegar (aceitic acid)
Bacteria
What is pasteurization?
The application of a high heat for a short time to kill harmful bacteria in beverages
Who used a chemical antiseptic (phenol) to prevent surgical wound infections? What time period?
Joseph Lister, 1860
What is germ theory?
The theory that human and plant diseases are caused by microorganisms
Explain Koch’s postulates
In 1876 Robert Kch discovered that bacterium causes anthrax and provided the experimental steps (Koch’s postulates) to demonstrate that a specific microbe causes a specific disease
Who inoculated a person with cowpox virus causing that person to become immune to smallpox? What is this type of protection called?
Edward Jenner, 1796; immunity
What is chemotherapy?
Treatment of a disease with chemicals
Chemotherapeutic agents used to treat infectious disease can be ___________ or antibiotics
synthetic drugs
What are antibiotics?
Chemicals produced by bacteria and fungi that inhibit or kill other microbes
Who discovered the first antibiotic? What was it?
Alexander Fleming, 1928; penicillium fungus which made penicillin; Clinically tested and mass produced in the 1940s
What is baceteriology?
The study of bacteria
What is mycology?
The study of fungi
What is parasitology?
The study of protozoa and parasitic worms
What is immunology?
The study of immunity
What is virology?
The study of viruses
Recombinant DNA technology
joining together of DNAmolecules from two different species that are inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry.
Microbes normally present in and on the human body are called ________.
normal microbiota
What are the harmful aspects of bacteria?
Food spoilage, disease
What are the different types of microorganisms? Give an example of each type.
- Bacteria: E. coli, streptococcus
- Archaea: halophiles, thermophiles, methanogen
- Fungi: yeasts, molds, and mushrooms
- Protozoa: amaoeba, euglena, plasmodium
- Algae: spirogyra, chorella, seaweeds
- Viruses: influenza, HIV, polio
- Milticellular Animal Parasites: flatworm, roundworm
Who developed the classification of microorganisms?
Carl Wose
What is fermentation? Give examples of some fermentation products
Fermentation is the microbial conversion of sugar to alcohol in the abscene of air
Examples: wine, beer, pickled cucumbers, yogurt
