ch 2

Question 1

wavelength

Answer 1

distance between peaks

Question 2

amplitude

Answer 2

height of each peak

Question 3

frequency

Answer 3

rate of vibration of wave or the number of wavelengths

Question 4

what is the refraction index ?

Answer 4

degree of change in transmission speed

Question 5

refraction?

Answer 5

if light enters a substance with a HIGHER refractive index it SLOWS DOWN and bends TOWARDS the normal lint (AWAY from the boundary)

Question 6

what occurs with a convex lens ?

Answer 6

meets a focal point
ex: glasses, contact lenses

Question 7

what occurs with a concave lens?

Answer 7

refracts light away from a focal point
ex: flashing light
CAVE=FLASHLIGHT

Question 8

what is contrast?

Answer 8

create of stark difference in COLOR

Question 9

what is resolution?

Answer 9

ability to tell that two separate points or objects are separate
number of pixels

Question 10

who used a compound microscope ?

Answer 10

galileo galilei

Question 11

who used the 1st simple microscope?

Answer 11

leeuwenhoek

Question 12

who coined the term cells?

Answer 12

robert hooke

Question 13

what adjusts the light intensity on a bright field microscope ?

Answer 13

rheostat

Question 14

bright field microscope

Answer 14

produces an image on a bright background

Question 15

dark field

Answer 15

-producing a brighter image on a dark background
- useful for viewing live specimens

Question 16

phase contrast

Answer 16

-high contrast
-high resolution
-w/o staining
-used for viewing live specimens and structures such as endospores and organelles

Question 17

differential interference contrast (DIC)

Answer 17

-3d appearance
-makes it useful in distinguishing structures within live, unstained specimens
-images reveal detailed structures within cells

Question 18

fluorescence

Answer 18

-uses fluorescent stains
-distinguish between living from dead cells
-or to find locations of particular molecules within a cell

Question 19

confocal

Answer 19

-uses a laser to scan multiple a planes
-useful for examining thick specimens such as biofilms

Question 20

two photon

Answer 20

Uses a scanning technique fluorochromes and long wavelength light (infrared) to penetrate deep into taking specimens such as biofilms 

Question 21

transmission (TEM)

Answer 21

Uses electron beams that passed through a specimen to visualize small images; useful to observe small thin specimens such as tissue sections and subcellular structure

Question 22

Scanning (SEM)

Answer 22

uses electron beams to visualize surfaces; useful to observe the 3d surface details of specimens

Question 23

scanning tunneling (STM)

Answer 23

Works best on conducting material but can also be used to tell me organic materials such as DNA

Question 24

atomic force (AFM)

Answer 24

Useful to observe specimens at the atomic level and can be more easily used with non-conducting samples

Question 25

wet mount

Answer 25

good for viewing a life specimen

Question 26

fixed mount

Answer 26

smear; good for staining

Question 27

basic stain

Answer 27

-Positively charged ions -basic fuchsin crystal violet, malachite green, safranin methylene blue

Question 28

acid stain

Answer 28

-Negatively charged ions -eosin, Rose Bengal, acid fuchsin

Question 29

Positive stain

Answer 29

Dye/scene is absorbed into the cell

Question 30

negative stain

Answer 30

dye/stain is absorbed into background

Question 31

Simple stains

Answer 31

-Single stain -emphasizes structures

Question 32

Differential stain

Answer 32

-Differentiates organism based on stain interactions -2+ stains

Question 33

Gram stain

Answer 33

-Distinguishes different cell wall components -Important clinical diagnostic tool -steps include: Heat fix smear, primary stain with crystal violet, Mordant which is iodine, decolorizer which is alcohol and finally counterstain with safranin 

Question 34

Gram-positive cell wall

Answer 34

Has a thick Peptidoglycogen which then means that it is able to absorb the crystal violet hence the turning of purple of gram-positive cells

Question 35

Gram-negative cell walls

Answer 35

Has a thin peptidoglycan wall 

Question 36

Acid fast stain

Answer 36

-Diagnostic tool for detection of my colic acid and mycobacterium spp. -steps: heat fix smear, Primary stain (carbolfuschin), decolorizer, counter stain (methylene blue)

Question 37

Capsule stain

Answer 37

-Diagnostic tool for detection of protective coating -Dyes does not penetrate capsule -steps: no heat smear, primary stain (india ink)

Question 38

Endospore stain

Answer 38

-Identification of endospore formers -schaeffer fulton method: Uses he to push the primary stain into the endospores  -steps: heat fix smear, primary stain (malachite green), decolorizer (water), counter stain (safranin) -Important for identifying bacillus and clostridium

Question 39

Flagella stain

Answer 39

-Identification of flagella appendages -bacteria, archaea, eukaryotes -steps: No heat smear, primary stain (specialized), decolorizer (water), counterstain (carbol fuschin)

Question 40

TEM

Answer 40

-Samples Annalise must have very thin sections -Specimen embedded in plastic resin and dehydrated -stained with electron dense heavy metals

Question 41

SEM

Answer 41

-More dehydrated-critical point drying with liquid CO2 -Sputter coated with metal