Micro Quiz 2

Ch 4-cell wall Ch6 media-serial dilutions

How big and what are the shapes of prokaryotes?

micrometers; bacillus (rod-shaped), coccus (sphere-shaped), spirals: vibrio (comma), spirillum (spiral), spirochete (cork screw)

What are pairs, clusters, chains, and groups of 4 of prokaryotes called?

pairs: diplococci and diplobacilli

clusters: staphlococci (cluster of spheres)

chains: streptococci and streptobacilli

groups of 4: tetrads

What is the glycocalyx of a prokaryote and the 2 types?

external to cell wall, viscous and gelatinous;

capsule: neatly organized and firmly attached, protect from phagocytosis, Ex. Bacillus anthraces and Streptococcus pneumonia

slime layer: unorganized and loose, can be washed off, Ex. Streptococcus mutant

What is the flagella and its 3 parts?

appendage of external cell and propel bacteria;

filament: outermost region

hook: attaches to the filament

basal body: consists of rods and pairs, anchors to cell wall

How can the basal body be used to distinguish a prokaryote?

2 rings: gram positive

4 rings: gram negative

What are the 4 types of flagella?

peritrichous: distributed over cell

monotrichous: single flagella

lophotrichous: tuft of flagella from 1 pole

amphitrichous: flagella on both poles of the cell

What is endoflagella?

found in spirochetes (Treponema pallidum), move like a corkscrew

What is fimbriae?

hairlike appendages that allow attachment

What is pili?

can help motility and transfer DNA from cells

What is the cell wall?

prevents lysis, made of peptidoglycan, contributes to whether prokaryote is disease causing

What is culture media?

nutrients for microorganisms

What is inoculum?

microbes introduced into a medium

What is the difference between a culture and sterile?

culture: microbes growing

sterile: do not contain microorganisms

What is the liquid and solid cultures in the lab?

liquid: broth

solid: agar, liquid when boiling

What is complex, reducing, and selective media?

complex media: trypic soy broth, trypic soy agar (TSA)

reducing media: used for anaerobes (no oxygen) Ex. clostridium

selective media: bacterial specific

What is TSA and MSA?

trypic soy agar (TSA): most all bacteria can grow in; gram positive and negative, fungi

mannitol salt agar (MSA): selective because of the salt; Ex. Staphylococcus

What is differential media?

Staphylococcus auerus ferments sugar, turning it from red/pink to yellow

What is eosin methylene blue?

selective (only gram positive can grow) and differential (tells difference between E. coli and others); green sheen

What is a colony and why do we streak plate?

colony: cluster of same species arising from 1 cell

streak plating is used to dilute and isolate colonies

What is binary fission and generation time?

binary fission: how bacteria will replicate, done exponentially or logarithmic

generation (doubling) time: time required for a complete fission cycle

How do you find the bacteria amount after binary fission?

2 to the power of whatever time

If a bacteria replicates every 20 minutes how many will there be in 1 hour?

20 minutes goes into an hour 3 times, 2³= 8 bacteria

What is the growth curve and its 4 parts?

predictable pattern of growth over time

1. lag phase: preparing for growth

2. log phase: exponential growth

3. stationary phase: cell growths and deaths are equal

4. death phase: cells die exponentially

How do you perform serial dilution?

each test tube is full of 9ml of broth, add 1ml to first tube (1:10), add 1ml from first tube to 2nd tube (1:100), and so on (1:1000), (1:10,000)

How do you find the colony factor units?

dilution factor x # of colonies = CFUs/ml

What is the minimum and maximum number of colonies?

30-300 colonies