bio 261 exam 1

media

"food" for bacteria

A solid medium is called \___________

agar

what is agar made from?

a polysaccharide made from algae

what is agar made to do?

turns liquid into a solid

liquid\=broth\=

Tryptic Soy Broth (TSB)

TSA (Trypticase Soy Agar) you can either have that in a

slant form ( has test tube), plate ( petri dishes), Deep (tube that have 15 militer of media).

TSA is a general purpose ...

growth medium

Bacteria reproduce by

binary fission

binary fission meaning

that one bacteria divides into 2 each of those divides again and then again and it keeps going and going.

when bacteria cells divide, are they genetically the same?

yes, The new cells are identical to the first cells

how do colonies form?

As cells pile up on each other they become a colony remember a colony comes from one cell.

enriched media example

blood agar

why is blood agar enriched?

cause it has 5% sheeps blood

MSA stands for

Mannitol Salt Agar

what is MSA?

it is selective for staphylococcic because it contains 7.5% sodium chloride and it is differential because it contains mannitol which is a fermentable sugar.

With the cell walls, if you have a thick peptidoglycan wall you will have

pitidoglycan

are acid based bacteria negative or postive gram?

positive, but they have mycolic acids in the cell wall

mycolic acids makes the cell wall \_______, which makes acid grow \______

waxy; slow

do waxy cell walls stain good?

no

bacteria that causes tuberculosis and causes leprosy

Mycobacterium

Mycobacterium and mycolic acids have what in common?

both waxy (unique for acid-fast bacteria)

Acid fast stain

The bacteria keep there color after they been decolorized with alchol. Keep the primary color which is red after decolorizing with acid alchol.

Nonacid fast stain what color?

blue

why do Nonacid fast stain blue?

the metylene blue counterstain

associated with walking pneuomia

Mycoplasma

Does mycoplasma have a cell wall?

no

do viruses have cells?

no

Can viruses have both DNA and RNA?

No, one or the other (they cant go through Transcription or translation)

Examples of Bacteria phages

• T4 is a lytic phage that infects E.coli (lytic means it lyses its host)

• Lambala Is a lysogenic phage it also infects E.colli but it incorporates its viral DNA into the E.Coli DNA from chromosomes

when bacteria grows, does it copy a viruses DNA?

yes

An example of a human virus is

HIV

a human virus is called a

reterovirus

Reterovirus

an RNA virus that has an enzyme called reverse transcriptase and that enzyme copies the single stranded RNA into double stranded DNA and that DNA incorporates into the chromosome of the T-helper cells

what cells are considered the host?

T-cells

latent or lysogenic

no reproducing

envelope virus

the membrane surrounding the virus

diff btw envelope and naked virus

no envelope and they typically lyse (kill) there host

Bioremediation

Use of living organisms such as prokaryotes, fungi, or plants to detoxify polluted ecosystems. ( ex: oil spill) they put bacteria into the spill and the bacteria converts the oil to carbon dioxide (CO2) and water (H2O).

legumes

Plants with seed pods that have nitrogen fixing bacteria that take out nitrogen so the plant can live

Resoultion of light microscope is

0.2 microns

To look at bacteria you have to use what lens?

oil immersion/objection lens (1000X bigger)

chromophore

colors that gram staining makes

gram positive color

purple

gram negative stains

pink/red

charge Cells have a\_________ charge because of that basic stains binds to the cells and that is where the color is

negative

means one stain or dye

Simple stains

why do you heat up the slide?

it will kill the bacteria and makes the cells stick to the slide, otherwise you can wipe off the bacteria

Acidic or negative stain has a \________ Chromochore

negative

Do you heat fix a negative stain?

no, because you dont want the cells to shrink (need a perfect measurement)

Gram stain crystal violet \=

1 stain

Crystal violet is the primary stain everything will stain

purple (rinse after)

Gram's Iodine\=

mordant

The mordant combines with the \_______. The iodine combines with the \_________

Crystal violet

70% Ethanol

decolorizer

Why the decolorizing is a crucial step for gram staining?

Gram negative will wash out the dye and gram positive will stay purple

Safranin

counterstain

Safranin is a \____ cell because the cell was decolorized it will turn light \____.

red; red

Gram positive will turn dark \_______ because the purple and red will turn dark \_______

purple

Gram positive has thick peptidoglycan cell walls so they retain the crystal violet making them stain \______.

purple

Gram negative have thin peptidoglycan cell walls and they also have an outer membrane that gets dissolved by the alcohol, therefore it stain \____

red

acid fast stain examples

Carbol fuschin, Acid alcohol, metheylane blue

Acid fast stains \____ nonacid fast stain \_____.

red; blue

Endospore stain

A differential stain used to detect the presence and location of spores in bacterial cells. green

Bacillus (aerobic) grows in

the presence of oxygen

Clostridium (anaerobic) grows

without oxygen

Bascillus and Clostridium have to both be

be heated and steamed (b/c of thick cell walls that wont show up on a stain)

Morphology

study of form

we measure bacteria in

micrometers

examples of the arrangement of bacteria

clusters, pairs, chains, tetrads, and singles

TEM aka

transmission (you see inside or through the cells)

SEM aka

scanning (you see only the surface)

are specimens dead or alive in SEM?

always dead

resolution meaning

seeing separate cells

how to make a pure culture

get a quadrent streak for isolation and that colony came from one bacterium

Koch's postulates proves that

certain diseases is caused by pathogens (He connected diseases with bacterial pathogens.)

Griffith

was the first person to do a transformation experiment

Transformation is the \_____________________. Remember that DNA carries genes and genes codes for proteins.

uptake of free DNA by a cell

cells that undergo transformation

a bacteria that is naturally competent cell

what bacteria did Griffith use?

Streptococcus Pneumoniae (has capsules and cocci)

The function of a capsule

it allows the bacteria to avoid phagocytosis by the white blood cells

Having a capusle is what causes a \________ factor for the bacteria

virulenece (carries diseases)

how do capsules look?

smooth and slimey

Chromones have all genes and capsules

true

Streptococcus pyogenes

bacteria (strep throat)

Anabeana

cyanobacteria (seen in water)

Methanococcus jannaschii

Archaea (lives in thermal vents)

Archaea have pseudomurein meaning

the bacteria have a different sugar in their cell walls

fungi has \_____ in their cells walls

chitin

the study of bacteria

bacteriology

Rhizopus stolonifer

bread mold

Trichuris vulpis

dog whipworm

Spirogyra

green algae

average wavelength of visible light

550 nm

average wavelength of electron microscopes

0.01 nm (closer)

do you have to have a pure culture to figure out the type of bacteria?

yes

throat swabs

blood agar is TSA with 5% sheeps blood
bacteria strep can cause B hemolysin C protein

What is the cell membrane made of?

phospholipid bilayer

Outside the cell membrane of bacteria is going to be the

peptidoglycan cell wall (If it has a capsule the capsule would be outside of the cell wall)

Capsules are typically \____.

polysaccharide (some have protein)

Fimbre

bacteria use this to bind to various surfaces (attachment)