Viewing and Classifying Bacteria Learning Checks

Define Microscopy

Using light or electrons to magnify objects

How is total magnification calculated?

Ocular x Objective (i think ocular is always 10x)

Why do we stain bacteria?

To make the colorless small ones visible to us

Define smear?

a thin film of bacteria on a slide

Why is a pinpoint amount of bacteria used to prepare a smear?

To let the bacteria stain and decolorize evenly

List three reasons why smears are heat fixed?

To kill the bacteria, makes it easier to stain, and adhere them to the slide

What is the overall charge of bacteria?

Negative

Are positively charged, negatively chard, or neutral dyes used to stain bacteria?

Positive (i think since bacteria is neg)

How many positively charged dyes are used insimple stains?

1

What does a simple stain allow you to learn about the bacteria?

Size, shape, and arrangement

How many positive charged stains are used in differential stain?

2

List the reagents (be specific) of the Gram

stain AND state the color(s) of the bacteria at each

step.

Primary stain

Use the following terms to list the function of each

reagent in the Gram stain: mordant, decolorizer,

secondary stain, primary stain.

look up

The gram stain divided bacteria into how many groups?

2 positive and negative

The staining difference between the gram stains is based on the different in the bacterial cell _____?

cell envelope

List the genera of acid fast bacteria?

myobacterium and nocardia

What does the acid stain show in the bacteria?

if it has myolic acid (waxy lipids) in their cell walls

Why do we being with a slide warmer for the acid stain

To heat the mycolic acid up, this allows penetration in the waxy cell wall

list the reagents in order of the aid stain and its functions

Carbol fuchsin- primary stain

acid alcohol- decolorizer

methylene blue- secondary stain

List the 2 genera of bacteria that produces endospores

bacillus and clostridium

What does the endospore stain show the bacteria can produce?

endospores

List two thing in the endospore procedures that stain the endospores

a slide warmer to allow the satin in and s filter paper to reduce evaportation.

list the reagents and function in the ednospore stain procedure

Malachite green- primary stain

Water- decolorizer

Safranin- secondary stain

Why don’t positive or negative stain adhere to a capsule

the capsules has no charge

do we fix heat the smear?

no it will destroy the capsule

list the primary and decolorizer in the capsule stain

crystal violet and cooper sulfate

why is water not used to rinse the capsule stain?

capsules are water soluble so it will rise away

What is the appearance of the bacteria and background in the negative stan versus simple and differential

it is Crytal violet

Describe the appearance of a capsule in a capsule stain

they take in no stain so they appear as a clear halo

List 3 bacterial morphologies

cocci/Coccus=round

bacilli/bacillus=rod

spiral =vibrio, spirillum, spirochete

Name how bacteria reproduces

via binary fission. bacteria copies its DNA, moves apart the copies, a cross wall forms, and the 2 bacteria can separate or stay together

How does arrangement of bacteria relate to binary fission

relates on how many planes the bacteria is in and if the bacteria stayed together or separated

Define classification

the process of putting things into groups based in way they are alike

List four reasons why we classify organisms

order and organization

enhances communication

helps predict structure and function

uncovers evolutionary connections

Define taxonnomy

the scientific way we classify organisms

List Linnaean taxonomy

kingdom, phylum, class, order, family, genus. species

Define binomial nomenclature

the way we name organisms

how do we correctly name an organism using binomial nomenclature

use linnaean genus and spiecs taxonomy, first genus capitalized first letter, second species lowe case first letter, underlined or italicized

Describe Whitakers taxonomic scheme

plantae (plants)

Animalia (anything with a back bone)

Fungi (mold and yeast)

Protista (parasites)

Manera (bacteria)

Describe woses taxonomic scheme why did he make it

to determine domains above kingdoms

Bacteria, Eukaryotes, and Archaea

Which kingdoms are included in woses domain

Bacteria- Monera

Archaea - Monera

Eukarya- plantae, animalia, fungi, and protista

What are the colors of acid fast and non acid fast?

acid fast is pink, non acid fast is blue

What is the procedure of an acid fast (aka baby) stain?

1. With the slide on the slide warmer, puddle positively charged carbol fuchsin on smear, add filter paper and wait for 2 minutes
2. After 2 minutes, remove filter paper and dispose of it in the trash. Move to the rack and rinse with deionized water.
3. add decolorizer (acid alcohol) to smear and wait 2-5 seconds
acid fast bacteria will stay stay pink
non acid fast bacteria will be colorless
4. Puddle positively charged methylene blue and wait for 1 minute. Rinse we deionized water
acid fast bacteria still pink
non acid fast bacteria blue

What are the colors of bacteria at the end of an endospore stain?

endospores are green, vegetative

cells are red

What are the steps of the endospore stain?

1. With the slide on the slide warmer, add filter paper to the smear and puddle positively charged malachite green to filter paper. Let it sit for 5 minutes
2. After 5 minutes, move the slide to a slide rack and wait an additional 5 minutes
3. After 5 minutes off heat, remove filter paper and dispose of it in the trash. Rinse with deionized water
(malachite green is driven into endospores/bacteria are still colorless)
4. Puddle positively charged safranin on smear. Wait 2 minutes and rinse with deionized water.
endospores will stay green, vegetative cells will be red