Micro Lab midterm

Question 0

Resolution

Answer 0

Ability to distinguish objects as separate from each other

Question 1

Magnification

Answer 1

Increase in apparent size of an object

Question 2

Why stain

Answer 2

View shape, + cellular structures

Question 3

Glycocalyx

Answer 3

Extracellular Polly metric material (glycoproteins)

Question 4

Purpose of the dye

Answer 4

Any die could be used instead of methane blue, the purpose of the dye is to contrast the charge of the bacteria, they have to be opposite.

Question 5

Autolysis

Answer 5

Destruction of tissue or so buy it’s own enzyme.

Question 6

Smear

Answer 6

A slide with microbes on it, ready to be stained

Question 7

What is the purpose of the heat fixing smear?

Answer 7

To denature of the bacterial enzyme

Question 8

What is a simple stain?

Answer 8

Determines morphology, size and arrangement.

Question 9

What will a positive stain due to the bacteria?

Answer 9

Positive Stan will turn bacteria purple color because bacterial has a negative charge it will be attracted to a positive (base)

Question 10

Negative stains

Answer 10

Stains the background, They are used for bacteria that are difficult to stain due to their size, used specifically used for Cocobacilli

Question 11

What is the key ingredient for staining

Answer 11

Alcohol, dissolving lipids

Question 12

Gram-positive

Answer 12

Has thick walls full with Peptidoglycan

Question 13

Gram-negative

Answer 13

Wall has LPS layer

Question 14

Penicillin

Answer 14

Will work on gram-positive

Question 15

Tetracycline

Answer 15

Will work on gram-negative

Question 16

Mycobacteria

Answer 16

No cell wall, no endospores or capsules.

Question 17

Acid-fast stain

Answer 17

Designed to identify mycobacteria a.k.a. tuberculosis and leprosy

Question 18

Acid fast positive

Answer 18

The cell wall lipids of the mycobacterium do not dissolve in the acid alcohol applied and thus the red stain does not wash off

Question 19

Capsule stain

Answer 19

“Sugarcoat”=Glycocalyx

Makes it more pathogenic or stronger

Where is this both stains acid and basic appears white like a halo around the cell

Question 20

Because of this capsule such as streptococcus pneumonia

Answer 20

WBC cannot phagocyte the bacteria efficiently and disease occurs

Question 21

Spore stain

Answer 21

In order for endospore just stay and we need to apply heat.

Difficult to stain you need to use steam a lot of stain visualization.

Question 22

Example of Spores

Answer 22

Anthrax, botulism, tetanus, diarrhea and Gangrene.

Question 23

Flagella stain

Answer 23

Two types of flagella:
Peritrichous (around all bacteria)
Polar (at one or both ends of the cell)

Difficult to sustain individualize

Question 24

Culture media

Answer 24

what do they need to grow?

Question 25

Used to test agar

Answer 25

Plate and slant

Question 26

How to sterilize Culture Media

Answer 26

To sterilize we need autoclave, "little oven", it has high steam and high pressure

Question 27

Nutrient broth vs nutrient agar

Answer 27

NB liquid broth, | NA solid in room temperature

Question 28

Selective medium

Answer 28

Tell her you don't want to keep the rest thatt you want to grow

Question 29

Differential medium

Answer 29

Use color change to tell the difference. | Example: used to examine staph

Question 30

Enriched medium

Answer 30

Add extra stimulus because it's difficult to grow. Requires boiled blood vitamin minerals Ex: Neisseria Gonorrhea

Question 31

Fastidious

Answer 31

Difficult

Question 32

PE

Answer 32

Kills gram-negative bacteria

Question 33

Mannitol salt agar

Answer 33

Rare sugar alcohol

Question 34

S. Aureus vs. S. Epidermis

Answer 34

S.A-very dangerous can eat mannitol. Produces acid waste (yellow) S.E.- harmless cannot eat mannitol stays pink.

Question 35

Streak plate technique

Answer 35

Separate different bacterial species from each other when they are in a mixture

Question 36

Isolation of colonies

Answer 36

Hey call me represents a single bacterium and it's overnight descendants

Question 37

Alpha

Answer 37

Partial breakdown of the red blood cells (greening)

Question 38

Beta

Answer 38

Total distruction of RBCs Very dangerous White/ clear zone

Question 39

Gamma

Answer 39

No distraction of RBCs

Question 40

Serial dilution of cultures

Answer 40

This is how we count bacteria

Question 41

To test a serial dilution of cultures

Answer 41

We have to get a sample to colony level meeting only one bacteria.

Question 42

Dilution factor

Answer 42

How much you diluted

Question 43

Bacteria in urine should be

Answer 43

Less then 10^5. If not you have to get antibiotics

Question 44

Calculation of number of visible bacteria in the original sample

Answer 44

Number of colonies 1 ---------------------- X ---------------- Volume places. Dilution factor