Microbiology Vocab Flashcards
Microbiology
a specialized area of biology that deals with living things that are too small to be seen without magnification
Microscopic
So small that is only visible by microscop
Microorganism/Microbe
are microscopic organisms
bacteria
Category of prokaryotes with peptidoglycan in their cell walls and circular chromosomes. Widely distributed in all earths environments.
Archae
Prokaryotic single-celled organisms of primitive origin that have an unusual anatomy, physiology, and genetics. Live in very harsh environments.
Protozoa
A group of single celled eukaryotic organisms
Fungi
Macroscopic and microscopic heterotrophic eukaryotic organisms that cand be single or multi cellular organisms.
Helminths
A term that designates all parasitic worms
Virus
Microscopic, acellular agent composed of nucleic acid surrounded by a protein coat
Algae
Photosynthetic, plantlike organisms that generally lack the complex structure of plants; they may be single-celled or multicellular and inhabit diverse habitats such as marine and freshwater environments, glaciers and hot springs
Eukaryotic cells
Differs from prokaryote because it has a nuclear membrane, a well defined nucleus, membrane bound sub-cellular organelles, and mitotic cell division
Prokaryotic cells
Small cells, lacking special structures such as a nucleus and organelles. All prokaryotes are microorganisms
Ubiquitous
Occur everywhere and are essential to life
Theory of Evolution
the accumulation of changes that occur in organisms as they adapt to their environments
Photosynthesis
light-fueled conversion of carbon dioxide to organic material accompanied by the formation of O2
Bioremediation
The use of microorganisms, either naturally occurring or artificially introduced, to restore stability or clean up toxic pollutants
Biotechnology
when humans manipulate microbes to make products in an industrialized setting
Genetic engineering
An area of biotechnology that manipulates the genetics of microbes, plants, and animals for creating new products and genetically modified organisms (GMOs)
Recombinant DNA technology
The transfer of genetic material from one organism to another to deliberately alter the DNA and produce a specific product
Pathogens
microbes that cause disease
infectious disease
Any disease caused by a microbe is term an infectious disease
Organelles
membrane-bound structures that perform specific functions
–Examples: nucleus, mitochondria, chloroplasts
–Only some eukaryotes are microorganisms
Viruses
NOT independently living cellular organisms
–Exist at the level of complexity somewhere between large molecules and cells
Spontaneous generation
the belief that invisible vital forces present in matter led to the creation of life
Sterile
completely free of all life forms including spores
germ theory of disease
established a link between a microbe and the disease it caused
Macromolecules
very large molecules
•Carbohydrates, lipids, proteins, nucleic acids
Monomers/polymers
Monomers are a simple molecule that can be linked by chemical bonds to form larger polymers
Hexose, Pentose, Glucose, Fructose, Lactose, Maltose, Sucrose
Carbohydrate: generally represented by the chemical formula (CH2O)n
•Monosaccharides and disaccharides are specified by combining a prefix that describes some characteristic of the sugar with the suffix –ose
Cellulose
a long, fibrous polymer composed of β-glucose
Agar
important component of culture media
Chitin
cell wall found in fungi
Peptidoglycan
component of the bacterial cell wall
Lipopolysaccharide
component of the gram-negative cell wall
Glycocalyx
functions in attachment or as a site for receptors
Triglycerides
Important storage lipid
Composed of a single molecule of glycerol bound to three fatty acids
Cholesterol
reinforces the structure of the cell membrane in animal cells and mycoplasmas
Protein
predominant organic molecule in cells
Amino acids
building blocks of proteins
Peptide
a molecule composed of short chains of amino acids
Polypeptide
contains an unspecified number of amino acids but usually has more than 20 and is often a smaller subunit of a protein
Primary structure (1°)
the type, number, and order of amino acids in the chain
Secondary structure (2°)
arises when functional groups exposed on the outer surface of the molecule interact by forming hydrogen bonds
- alpha helix
- beta-pleated sheet
Tertiary structure (3°)
created by additional bonds between functional groups
Quaternary structure (4°)
formed when more than one polypeptide forms a large, multiunit protein
Enzymes
protein catalysts for chemical reactions in cells
Antibodies
complex glycoproteins with specific attachment regions for bacteria, viruses, and other microorganisms
Nucleic acids
DNA, RNA, and ATP
•DNA: contains the special coded genetic program with detailed and specific instructions for each organism’s heredity
DNA
Double helix structure
•Formed by two very long polynucleotide strands linked by hydrogen bonds between complementary pairs of nitrogen bases
•Adenine pairs with Thymine
•Guanine pairs with Cytosine
RNA
the molecules responsible for translating the DNA program into proteins that can perform life functions
•Often a long, single strand of nucleotides
•Contains ribose instead of deoxyribose and uracil instead of thymine
Adenosine triphosphate (ATP)
a nucleotide containing adenine, ribose, and three phosphates
•Belongs to a category of high-energy compounds that give off energy when the bond between the second and third (outermost) phosphate is broken
•This releases energy to do cellular work
Cell
the fundamental unit of life
•Bacteria and protozoa: single cell
•Animals and plants: trillions of cells
Taxonomy
the science of classifying living things
Binomial system
a 2 name system; Genus species
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Example: Eukarya, Animalia, Chrodata, Mammalia, Primates, Homidonia, Homo, Sapien
The five I’s of microbiology
Inoculation Incubation Isolation Inspection Identification
Culture
to grow microorganisms
Medium (plural, media)
nutrients for the growth of microbes
Inoculation
the introduction of a small sample of microbes into media to culture them
Incubation
media containing inoculants are placed in temperature-controlled chambers
Pure culture
grows only a single known species
Mixed culture
grows two or more identified, easily differentiated species
Contaminated culture
has unwanted microbes
General purpose media
Grow as broad a spectrum of microbes as possible
Enriched media
Contains complex organic substances such as blood, serum, hemoglobin, or special growth factors (vitamins, amino acids) for the growth of fastidious (complex) microbes
growth factors
vitamins, amino acids
fastidious
complex microbes
Selective media
contains one or more agents that inhibit the growth of a certain microbe or microbes
Differential media
allow multiple types of organisms to grow but display visible differences in how they grow
Reducing medium
contains a substance (thioglycolic acid or cystine) that absorbs oxygen or slows the penetration of oxygen
Carbohydrate Fermentation Media
contain sugars that can be fermented and a pH indicator that shows this reaction
Transport Media
used to maintain and preserve specimens that have to be held for a period of time before clinical analysis
Assay media
used to test the effectiveness of antimicrobial drugs
Enumeration media
used to count the numbers of organisms in liquid samples
Isolation
based on the concept that if an individual cell is separated from other cells on a nutrient surface, it will form a colony
Colony
a macroscopic cluster of cells appearing on a solid medium arising from the multiplication of a single cell
real image
Objective lens: closest to the specimen, forms the initial image called the real image
virtual image
Ocular lens: forms the second image called the virtual image that will be received by the eye and converted to the retinal and visual image
2: Resolution (resolving power)
The capacity of an optical system to distinguish or separate two adjacent points or objects from one another
Refractive index
Refractive index: a measurement of the degree of bending that light undergoes as it passes from one medium to another
Principles of light microscopy
Magnification
Resolution
Contrast
Positive stain
dye sticks to the specimen and gives it color
Negative stain
does not stick to the specimen but settles some distance from its outer boundary, forming a silhouette
Simple stains
only require a single dye and an uncomplicated procedure
Differential stains
use two different colored dyes, the primary stain and the counterstain
Acid fast stain
differentiates acid-fast bacteria (pink) from non-acid-fast bacteria (blue)
Endospore stain
distinguishes between spores and vegetative cells (active cells)
vegetative cells
Active cells
Capsule staining
used to observe the microbial capsule, an unstructured protective layer surrounding the cells of some bacteria and fungi
Flagellar staining
used to reveal the flagella (tiny, slender filaments used by bacteria for locomotion)
flagella
tiny, slender filaments used by bacteria for locomotion
histones
Prokaryotes do not wind their DNA around proteins called histones like eukaryotes. Yoyo to wrap protein around
Pleomorphism
cells of one species may vary in shape and size, caused by variations in cell wall structure
cocci
spherical, ball-shaped bacterium
Diplococci
groups of two
Tetrads
groups of four
Staphylococci or micrococci
irregular clusters
Streptococci
chains
Sarcina
a cubical packet of 8, 16, or more cells
bacilli
Rod shaped bacterium
Diplobacilli
pair of cells with ends attached
Streptobacilli
chain of several cells
Coccobacillus
a short and plump rod
Palisades
cells of a chain remain partially attached by a small hinge region at the ends
Spirilla
occasionally found in short chains
Appendages
accessories that provide motility or attachment
motility
Bacterial locomotion
Monotrichous
single flagellum
Lophotrichous
small bunches or tufts of flagella
Amphitrichous
flagella at both poles of the cell
Peritrichous
flagella dispersed randomly over the surface
chemotaxis
Bacteria move in response to chemical signals
Fimbria
Small, bristle-like fibers sprouting off the surface of many bacterial cells
Pilus
used for attachment and genetic exchange during conjugation
Conjugation
partial transfer of DNA from one cell to another
S layer
Single layers of thousands of copies of a single protein linked together like chain mail.
–Only produced when bacteria are in a hostile environment
Glycocalyx
Composed of polysaccharides or glycoprotein units
–Used to avoid phagocytosis (recognition by the immune system) and for adhesion (biofilms)
Slime layer
loose, protects against loss of water and nutrients
Capsule
more tightly bound, denser, produces a sticky (mucoid) character to colonies on agar
cell wall
The cell wall helps determine the shape of a bacterium
Peptidoglycan
repeating framework of long glycan (sugar) chains cross-linked by short peptide (protein) fragments
Gram Positive Cell Wall
Thick, homogenous sheet of peptidoglycan
•Contains teichoic acid and lipoteichoic acid
–Function in cell wall maintenance and enlargement
–Contribute to the acidic charge on the cell surface
Gram Negative Cell Wall
Single sheet of peptidoglycan
•Thinness gives gram-negative cells greater flexibility and sensitivity to lysis (cell rupture)
Lysis
Cell rupture
L-forms
Some bacteria that naturally have a cell wall but lose it during part of their life cycle
Outer membrane
contains specialized types of polysaccharides and proteins
–Only on Gram negative bacteria
–Contains lipopolysaccharide (LPS)
Cytoplasm
a gelatinous solution encased by the cell membrane
–70 – 80% water
–Complex mixture of sugars, amino acids, and salts
–Serves as a pool for building blocks for cell synthesis or sources of energy
nucleoid
DNA is aggregated in a dense area of the cell called the nucleoid
plasmids
Many bacteria contain other, nonessential pieces of DNA called plasmids
bacterial chromosome
DNA of most bacteria exists in the form of a single circular bacterial chromosome
Ribosomes
site of protein synthesis, composed of rRNA and proteins
Endospore
Endospores resist extremes of heat, drying, freezing, radiation, and chemicals that would kill vegetative cells
Nucleolus
Found in the nucleoplasm
–Site of rRNA synthesis
–Collection area for ribosomal subunits
Chromatin
Made of linear DNA
When wound around histones, chromatin forms structures called chromosomes
Endoplasmic reticulum
a series of microscopic tunnels used in transport and storage
Rough endoplasmic reticulum (RER)
Endoplasmic reticulum with ribosomes attached
Originates from the outer membrane of the nuclear envelope and extends in a continuous network to the cell membrane
–Allows transport materials from the nucleus to the cytoplasm and ultimately to the cell’s exterior
–Ribosomes are attached to its membrane surface
Smooth endoplasmic reticulum (SER)
Endoplasmic reticulum with no ribosomes
Closed tubular network without ribosomes
–Nutrient processing
–Storage of nonprotein macromolecules such as lipids
Golgi apparatus
site of protein modification and shipping
Lysosomes
contain a variety of enzymes involved in the intracellular digestion of food particles and protection against invading microorganisms
Vacuoles
membrane bound sacs containing fluids or solid particles to be digested, excreted, or stored
Mitochondria
generate energy for the cell; “powerhouse of the cell”
Chloroplasts
capable of converting energy from sunlight into chemical energy through photosynthesis
Actin filaments
long protein strands
Microtubules
long hollow tubes
Intermediate filaments
ropelike structures
Cytoskeleton
Flexible framework of molecules cris-crossing the cytoplasm
•Functions: anchoring organelles, moving RNA and vesicles, permitting shape changes, movement
Hyphae
Long, threadlike cells found in the bodies of filamentous fungi
Pseudohypha
chain of yeast cells
Heterotrophic
acquire nutrients from a wide variety of organic sources/substrates
saprobes
Fungi that obtain nutrients from the remnants of dead plants and animals in soil or aquatic habitats
parasites
grow on the bodies of living animals or plants, although very few require a living host
Mycelium (fungi)
the woven, intertwining mass of hyphae that makes up the body or colony of a mold
Septa
segments or cross walls found in most fungi that allow the flow of organelles and nutrients between adjacent compartments
Spores
Fungal reproductive bodies
–Can be dispersed through the environment by air, water, and living things
–Will germinate upon finding a favorable substrate and produce a new fungal colony in a short time
Sporangiospores (fungi)
formed by successive cleavages within a sac-like head called a sporangium, which is attached to the stalk
Conidiospores or conidia (fungi)
free spores not enclosed by a spore-bearing sac
Ectoplasm (protozoa)
clear outer layer involved in locomotion, feeding, and protection
Trophozoite (protozoa)
motile feeding stage requiring ample food and moisture to stay active
Cyst (protozoa)
dormant resting stage when conditions in the environment become unfavorable
Flatworms
Have a thin, often segmented body plan
- Cestodes (tapeworms)
- Trematodes (flukes)
Roundworms/Nematodes
Have an elongated, cylindrical, unsegmented body
Hermaphroditic
the male and female sex organs are in the same worm
