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micro unit test 1

dtcc micro unit test 1

QuestionAnswer
what is a microbe? a small living thing that can only be seen with a microscope
What are some of the ways in which microbes interact with the environment? photosynthesis structure and content of soil, water, and atmosphere heat flow of energy and food in ecosysytem
What are some of the ways, harmful and otherwise, in which microbes interact with humans? bread, alcohol, cheese, treatment, cleaning up contamination
What is a pathogen? microbes that cause disease
How prevalent are pathogens among microbes? all over the world most common cause of death
What is the primary difference between prokaryotes and eukaryotes eukayrotic have nucleus and membrane organelles
what is a virus an obligate intercellular parasites
what are some important characteristics of viruses infect every type of cell needed for evolution
How would you recognize a properly written scientific or binomial name Escherichia coli. (italicized and underlined)
What do the two parts of that name indicate? combination of genus and species name
What are the major groups of microbes? Which are prokaryotes and which are eukaryotes? P- bacteria, e- protoza, e-fungi, e-algae, neither-viruses, p-archea
What are some characteristics of the major groups of microbes domain, most distinct from each other (taxonimic)
What were the first types of organisms to appear on Earth ancestor of bacteria, archea, eukaroytes
About how long did it take for more complex, multicellular organisms such as animals to evolve? billions of years
What are the three domains of life? bacteria, archaea, eukarya
List the ranks of the taxonomic hierarchy, from domain to species. Which level contains organisms that are most similar to one another domain (most different) kingdom plylum of divison class order family genus species (most similar)
Which contains organisms that are most different from one another? domain
How is rRNA relevant in classification of organisms rrna is different but nearly identical in species
Why is rrna used instead of DNA? not really affected by evolution
Organisms that are not microbes are always what: prokaryotes or eukaryotes Pro
bacteria minimum need cell membrane, bacterial, chromosome (dna), ribosomes, cytoplasm
bioremediation is ability to restore or clean up toxic pollutants
Genetic engineering? Deliberately alters genetics of microbes
Taxonomy? The science of classifying living things (to name)
Nomenclature? The assignment of names to the taxonomic categories
Classification? The arrangement of organisms into a hierarchy (kingdom)
Identification The process of discovering and recording traits of organisms so they can be placed in the taxonomic
Phylogeny How they relate to one another
How large are the smallest objects that can be seen by the human eye 1mm
How large are the smallest objects that can be seen by the light microscope 1(weird n) m
How large is a typical bacterium? 1and 10 (weird n) m
How does this compare to a typical human cell 1(weird n)m so bacteria is atleast 10x larger
What is magnification The process of enlarging the appearance.
What is resolution seeing clearly
How does the oil with immersion lens help? Reduces light scatter and increases resolution
Which part of the microscope magnify the image Lens
In a typical compound microscope what are the 2 lenses and where are they located? Ocular and objective lens, located on the nose piece
What set of lens on a compound microscope be rotated in and out Torret
How is total magnification calculated objective x ocular
Define refractive bending light as it passes from one medium to another
What Is contrast Ability to dee an object from the background
Why is contrast important in forming a good image? to be able to see the item fully
How can contrast be increased by using the iris diaphragm to reduce the intensity of the light
Categorize the types of microscope by their light source. visible lights, UV rays, electron beam,
What is each microscope best-suited to viewing bacteria and parasites, human/animal cells.
What are some considerations when determining how a sample is to be prepared for microscopy? living? what do you want to see? what microscope is available?
What are the advantages of live preparations (“wet mounts”) and fixed, stained specimens observed as near to their natural state as possible, provide true assessment of the size, shape, arrangement, color, and motility of cells.
What are some options when making a live preparation water, saline, or broth?
What is heat-fixing and what is the purpose of it Kill organisms and adhere them to the slides being used so they can take on stains.
What is the purpose of staining enhance visualization under light and electron microscopy
what are some disadvantages of live preparations (“wet mounts”) and fixed, stained specimens you can not view for a long time and not able to view in greater cellular detail
Which type of stain has colored specimens and a clear background? positive staining
What are the differences between simple stains and differential stains simple- 1 dye differential- 2 dyes
How do gram-positive and gram-negative bacteria appear under the microscope positive purple negative red
What important microbe is detected by acid-fast staining tuberculosis
Is India ink staining for capsules positive or negative staining negative
How does flagellar staining work enlarge flagella by coating outside then staining
Which type has a colored background and colorless specimens? negative staining
ocular lenses Magnify the image 10X.
body tube Conducts light rays from objectives to oculars.
arm Supports the upper part of the microscope. Use this and the base to carry the microscope.
nosepiece Revolving plate used to change the objective lens being used.
objective lens can be rotated in and out to give varying levels of magnification.
stage clips/ slide holder Holds the slide securely in place on the stage.
Mechanical stage The slide will rest on the stage.
condensor Condenses light waves into a cone shape and controls the amount of light that passes through the slide.
Diaphragm closes closes and opens the diaphragm
illuminator/ light source Provides the light that will pass through the slide
fine focus adjustment knob Used for final focusing. Use with high power and oil immersion.
coarse focus adjustment knob raisinh or lower the stage.
base Flat surface that rests on the table.
What structures do all bacterial cells have? cell membrane, cytoplasm, ribosomes, DNA
Which structures do most bacterial cells have cell wall
Which structures are only on certain bacterial cells outer membrane
How large is a typical bacterium 1-10 micrion
What are the principal bacterial shapes (hint – there are three) and what names do we use to designate them rods, spirals, spheres
What is pleomorphism due to individual vaiations in cell wall structure caused by nutritional or slight genetic differences
What are the terms used to describe grouped bacteria and variations on the principal bacterial shapes? pleomorphic
What is a flagellum a slender threadlike structure for swimming
Describe the motion of the flagellum run and tumble
Name and describe the external bacterial flagellar arrangements. Monotrichous (single) lophotrichous (small bunches same site) smphitrichous ( both poles)
What are running and tumbling run: counterclockwise smooth linear direction tumble: reversal of direction cell to stop and change course
what is chemotaxis movement of bacteria in response to chemical signals.
What are periplasmic flagella spirichete (spiral/ corkscrew shape)
Which organisms have them flagalla? What type of motion do they produce? corkscrew shape and unusual wriggly locomotion
What are pili and fimbriae? What are their functions fimbriae: Small, bristle-like fibers sprouting off the surface of many bacterial cells. Pilus – Long rigid, tubular structure made of a special protein ‘Pilin’.
What are nanotubes/nano wires? What is their function? Thin, long tubular extensions of cytoplasmic membrane Channels for nutrient or energy exchange
What are the two types of glycocalyx slime layer capsule
What is the glycocalyx composed of? made by bacteria, epithelia, and other cells
What roles can the glycocalyx serve? Performs protective, adhesive and receptor functions
What substance makes up the bacterial cell wall? Peptidoglycan - Repeating framework of glycans + Short peptide (protein) fragments
What macromolecules are combined in this substance? peptidoglycan
How does damage to the cell wall affect a bacterium? disrupts its integrity
Compare and contrast gram-positive and gram-negative cells. What features does each one have that the other one lacks? positive: thick peptidoglycan, cell wall negative: think peptidoglycan but is more felxible
Which type of bacterium has an outer membrane gram negative
What medical effect does lipopolysaccharide (LPS) have? produce endospores
In the Gram staining reaction, what does each step do? What happens if a given step is skipped? cystal violet dye, then iodine solution, a decolorizer, the counterstain.. skipped then it will be purple skipped may not get correct result
What are some options for atypical cell walls in bacteria and other prokaryotes? mycobacterium, protein or polysaccharide,
What are the main components of the plasma/cytoplasmic membrane? What is its function and how does it accomplish this? lipid bilayer with proteins. atp synthesis by holding enzymes
What is the difference between a chromosome and a plasmid? plama is a non essential piece of double stranded DNA
What shape is the bacterial chromosome? where is it found? circular nucleoid in cytoplasm
What is the function of ribosomes? protein synthesis
What designation is used for prokaryotic ribosomes? are attractive target for drug design found in bacteria
What designation is used for eukaryotic ribosomes? found in licing (animals, plants, fungi ect.)
What are the differences between an endospore and a vegetative cell? endospore- stress non stable vegetative- stable living conditions
What is the advantage of forming endospores survive extreme conditions
Under what conditions do endospores form? streesful conditions
What transforms them back into vegetative cells? germination
What is the medical significance of endospores? disease causing ability they can be pathogens
What are the primary differences between the two domains of prokaryotic cells? bacteria are found everywhere archaea found in unusual environments
Why are prokaryotes difficult to classify? because they share charateristics
How do we account for variations in a species when classifying prokaryotes? serotype, subspecies, strain, or type to designate bacteria of the same species that have differing characteristics.
Briefly explain the concept of “last common ancestor” as it relates to eukaryotic cells. common ancestor is nether eu or pro
How have eukaryotic organisms changed over time? aggregate and formed colonies evolved when individual cells lost the ability to survive on their own
Describe endosymbiotic theory. a large host cell & bacteria could become dependent on one another for survival, resulting in a permanent relationship. Over millions of yrs of evolution, mitochondria & chloroplasts have become more specialized & today they cannot live outside the cell.
What major group of eukaryotes has flagella? unikonts
How are eukaryotic flagella different from prokaryotic flagella? protozoa
Describe the structure and function of cilia. Cilia are slender, microscopic, hair-like structures or organelles
What are the differences between cilia and flagella? flagella- single slide past each other cilia- shorter and many, beat back and forth (oar strokes), feeding and filtering function
What are the functions of a eukaryotic glycocalyx? Protection Adherence to surface Reception of signals from other cells and environment
Which eukaryotic groups have cell walls and which do not? Do- fungi and algae dont- protozoa and helminths
What are fungal cell walls made of? Thick inner layer of polysaccharide fibers composed of chitin or cellulose Thin outer layer of mixed glycans
Describe the general structure of the cytoplasmic membrane. What is its function? Bilayer of phospholipids with proteins separates the interior of a cell from its outside environment
What is a hyphae? Long thread like cells found in the bodies of filamentous fungi or molds
How does hyphae relate to pseudohyphae? both in molds/fungi/ attach to one another
What are the differences between mold and yeast? yeast-Round oval shaped and undergoes asexual reproduction mold- multicellular sexual or asexual
What term describes fungi that can switch between the two forms? dimorphic
What are some clinically relevant aspects of fungi? causes harms to humans
What are the active and inactive stages of a protozoan? active/ trophozoite- feeding stage needs food and moisture inactive/cyst- unfavorable environment stress environments no eating
What is the advantage of forming cysts? resistant to heat and drying chemicals
Why are cysts clinically relevant? spread diseases
What are the major groups of protozoans based on motility? Amoeba (sarcodina/ Pseudopods Ciliates (Cilophora) Flagellates (Mastigophora) Apicomplexans (Nonmotile)
What are the major groups of helminths? flatworms and round worms
Briefly describe the helminth lifecycle. egg, larva, adult.
describe nucleus the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
describe endoplasmic reticulum a network of membranous tubules within the cytoplasm of a eukaryotic cell
define golgi apparatus a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport.
define lyosomes an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.
describe mitrochondria in which the biochemical processes of respiration and energy production occur.
chloroplasts a plastid that contains chlorophyll and in which photosynthesis takes place. (in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place.
define ribosomes They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
define cytoskeleton a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.
When did eukaryotic cells first appear? 2-3 billion years ago
when you miss a step on gram staining it will be purple
gram staining is differential
fungal had chitin walls
staphyloccus aureus is a gram positive and round shaped
stephyococcus shapes are coccus, rod, bacillus or spiral
cocci are oval shape
what is an organic molecule molecule that must include at least both carbon and hydrogen
what is an inorganic molecule molecule that does not contain both carbon and hydrogen
Created by: xokitty17xo