Taxonomy Flashcards
Name 4 ways microbial cell structure and function came to be studied
Light microscope, improving contrast in light microscopy, electron microscope, and taxonomy and systematics
How can microbes be identified?
Microscopic appearances, characterization of cellular metabolism,determination of nutrient requirements, products given off during growth, the presence of enzymes, and mechanisms for deriving energy, and then Genetic and immunologic characteristics
Describe eukaryotic cells
has a central control structure called a nucleus, which
contains the cell’s DNA
Describe prokaryotic cells
does not have a nucleus; its DNA simply resides in the middle of the cell
What are the 3 domains to life, Respectively?
Bacteria, archaea, eukarya
What are the 6 Kingdoms?
Plant, Animal, Fungi, Protista, Moneran, Archaea
What is Protista?
(eukaryote) algae- photosynthesis, protozoans (water mold, slime mold, golden algae, and brown algae)
What is Fungi?
(eukaryote) mold and yeast
What is Archaea?
(prokaryote) archaebacteria: methanogenic, halophilic, thermophilic
What is Moneran?
bacteria, blue-green algae, mycoplasma, rickettsia, and chlamydia
Name the 6 kingdoms
Plant, animal, fungi, moneran, Protista, archaea
Fungi is…
Mold and yeast (eukaryote)
Protista is…
Algae, protozoan water mold, slime mold, golden algae , brown algae (eukaryote)
Archaea is…
Methanogenic, halophillic, thermophillic (prokaryote)
Moneran is…
Bacteria, blue-green algae, mycoplasma, rickettsia, chlamydia
Algae microorganisms are….
Phototrophic
Fungi microorganisms are…
non photosynthetic that contain a rigid cell wall
Protozoa
unicellular eukaryotes that lack a cell wall
Helminths
flatworms and roundworms
Name the 7 different ways you can classify Bacteria
shape, size and structure, chemical activities, nutrient requirements, physical conditions under which they grow, ability to cause disease, staining behavior
Describe the Monerans
Viruses are not considered cells because?
they have no metabolic abilities of their own, rely completely on biosynthetic machinery of infected cell, infect all types of cells, smallest virus is 10nm in diameter
Describe a Eukaryotic structure
has larger cells and membrane containing organelles
Describe a Prokaryotic structure
has smaller cells and do not have membrane containing organelles
Describe the differences in structure of a Prokaryotic cell and a Eukaryotic cell
they both have plasma membranes, cytoplasm, DNA, and ribosomes; P only has nucleoid region , E only has a nucleus
What is a light microscope?
a bright field or compound microscope used to stain bacteria because prokaryotes lack contrast with surrounding media
What is a fluorescent microscope?
use ultraviolet (can’t see) light ans special dyes
What is a phase contrast microscope?
increases the contrast between the cell and media by using special lenses, best at studying living cells; don’t have to stain
What is a dark field microscope?
outlines of organisms can be seen and has the greatest contrast
What is magnification?
amount of enlargement
What is working distance?
space between specimen and lens
What is depth of field?
distance between nearest and farthest object that are in focus
Describe coccus shape and give an example
circular shape; ex. staphylococcus aureus
Describe rod shape and give an example
cylinder shape; ex. bacillus subtilis
Describe spirillum shape and give an example
spiral shape; ex. spirillum volutans
Describe the components of the Gram stain
separate bacteria into groups with gram-positive (purple) and gram negative (red/pink)
Describe the components of the Acid stain
acid-fast (hot pink) non acid-fast (blue), cell walls holds fast to the dye when washed with acid alcohol decolorizer; originated to detect mycobacterium tuberculosis
Describe the components of the Endospore stain
dye is forced by heat into resistant bodies that distinguish between spores and vegetative cells; significant in identifying gram positive, spore-forming members
What are special stains? Name two and what they do
they are used to emphasize cell parts that are not revealed by conventional staining methods; capsule staining observes the microbial capsule, flagellar staining reveals tiny, slender filaments used for locomotion
What does an Electron Microscopy do?
uses electrons instead of light and requires special techniques
What does a Transmission Electron microscopy (TEM) do?
thin sectioning, shadow casting, negative staining, freeze etching
What does Scanning Electron microscopy (SEM) do?
shows surface structure
What is Taxonomy?
the science of identification, classification, and nomenclature
What is Systematics?
the study of the diversity of organisms and their evolutionary relationships
What is Phylogeny?
Evolutionary history of a group of organisms inferred indirectly from nucleotide sequence data
What are Molecular clocks? What is a major assumption of it?
certain genes and proteins that are measures of evolutionary change; nucleotide changes occur at a constant rate, generally neutral, and random
Archaea are more closely related to _______ than _______.
eukarya; bacteria
Eukaryotic microorganisms were the ancestors of….
multicellular organisms
Describe the cell membrane
semi-permeable lipoprotein structure located inside the cell wall with little mechanical strength and is a permeability barrier; 75-100 A in thickness
What are membrane proteins?
Outer surface of cytoplasmic membrane that interacts with a variety of proteins that bind substances or process large molecules for transport and involve energy-yielding reactions
What are integral membrane proteins?
firmly embedded in the membrane
What are peripheral membrane proteins?
one portion anchored in the membrane
What is cytoplasm?
complex mixture of sugars, amino acids, and salts that serve as a pool for building blocks for cell synthesis or sources of energy; 70-80% water
Where is most of the hereditary material of most bacteria?
in the nucleoid and contains 1 DNA ad Ca++ and Mg++
What are plasmids?
nonessential pieces of DNA that have protective traits like drug resistance and toxin and enzyme production
Describe ribosomes
composed of rRNA and proteins with large and small unit and is the site of protein synthesis
What are peptidoglycan?
a rigid crosslinked network outside the cell membrane that provide protection from osmotic lysis and determine cell shape
Describe a Gram positive cell wall
thick peptidoglycan and lack lipopolysaccharide layer and has a peptide bridge, teichoic acids on the outside of the wall , and uses treatment with lysozyme yields protoplasts
Describe a Gram negative cell wall
direct cross linking thin peptidoglycan composed of outer and inner layer and treatment with lysozyme yields spheroplasts
Name two prokaryotes that lack cell walls
mycoplasmas and thermoplasma
What is the S layer?
single layers of thousands of copies of a single protein linked together that only produce when bacteria are in hostile environments
Describe the slime layer (capsule, glycocalyx)
produced by Klebsiella pneumoniae that varies in thickness, density, and adherence; gel-like structure composed of complex polysaccharides, nitrogen containing compounds and polypeptides that prevents desiccation resist phagocytosis and bacteriophages, and aid in attachement
What is Sporulation?
when conditions become unfavorable
What is germination?
when favorable conditions return
What are bacterial endospores?
resistant to heat, drying, chemical disinfection, stains, and radiation
What is bacterial flagella and what does it do?
a helical structure composed of protein flagellin that rotates a hook that causes motion and aids in motility; polar, amphitrichous, lophotrichous, and peritrichous
What is gliding motility?
flagella-independent movement that typically occurs along long axis of cell that requires surface contact
Chemotaxis is…
movement across a chemical gradient
Phototaxis is…
movement across a light gradient
Aerotaxis…
repsonse to oxygen
What is Fimbriae?
a short straight filamentous protein structures on surface of cell that help organisms stick
What is Pili?
short straight filamentous hollow protein structure on surface of cell that allows DNA transfer between bacteria
What is a gas vesicle?
found in cyanobacteria and is a spindle shaped structure that is composed of only protein and is very rigid
Name 6 inclusion bodies
PHB, glycogen, polyphosphate, carbonate minerals, sulfur, magnetosomes
