Exam 2 Flashcards
What is the gram stain appearance of Escherichia coli
Gram-negative bacilli in singles
What is the gram stain appearance of Serratia marcescens
Gram-negative bacilli in singles
What is the gram stain appearance of Bacillus subtilis
Gram-positive bacilli in chains
What is the gram stain appearance of micrococcus luteus
Gram-positive cocci in tetrads
What is the gram stain appearance of staphylococcus epidermidis
Gram-positive cocci in clusters
colony morphology of E.coli
white,moist colonies
colony morphology of serratia
red colonies
colony morphology of bacillus subtilis
dry feathery white colonies
colony morphology of micrococcus luteus
yellow colonies
colony morphology of staph
white colonies
colony morphology of chromo bacterium violaceum
purple/violet colonies
the first step (primary stain) in a gram stain procedure
crystal violet for 1 minute
the second step in a gram stain procedure
grams iodine for 1 minute
what else is grams iodine called? and why?
mordant, it makes the cell more receptive to staining
the third step in a gram stain procedure
95% ethanol
what does the alcohol do?
cause the crystal violet-iodine complex to leave the cell wall if the bacteria is gram negative
the fourth step in a gram stain procedure
safranin red
what is the technique that must be used EVERY time you are working with bacteria
aseptic techniques
what is the cell wall of bacteria composed of
peptidoglycan
what can be prescribed that works differently on gram positive or negative bacteria
antibiotics
what two domains exist in the kingdom prokaryotae
Archaebacteria (ancient forms) and Eubacteria (modern bacteria)
why do bacteria react differently to the gram staining process
because of the differences in their cell walls
what is the cell wall structure of gram-positive bacteria
layers of peptidoglycan laying above the cell membrane and secured by amino acids
what is the cell wall structure of gram-negative bacteria
cell walls stacked with a membrane layer- a layer of peptidoglycan and a top membrane layer
what is a protist
a eukaryotic organism that is not a plant,animal or fungus
why are protists classified as eukaryotes
they have a true nucleus
what does an amoeba use for motility
psuedopodia (false foot)
what is a unicellular fungi and what are they called
single-celled fungi, yeast
what is “budding” in yeats
a type of asexual reproduction
