Chapter 3

Question 1

Kilo meter = 10^ — of a m

Answer 1

10^3 (1000m)

Question 2

1 decimeter = 10^ — of a Meter

Answer 2

10^-1 (.1m)

Question 3

1 centimeter = 10^— m

Answer 3

10^- 2 (.01) m

Question 4

1 millimeter = 10^— m

Answer 4

10^ -3 (.001 m )

Question 5

1 micrometer = 10^—- m

Answer 5

10^ -6 (.000001)m

Question 6

1 nanometer = 10^—-

Answer 6

10^-9 m

Question 7

1 picometer = 10^— m

Answer 7

10^-12 m

Question 8

Larger to smaller conversion number (increases or decrease)

Answer 8

Increase

Question 9

What the ocular lens does

Answer 9

(Eyepiece) remagnifies image formed by objective lens

Question 10

Body tube, what it does

Answer 10

Transmitts image from obj lens to ocular lens

Question 11

Primary lenses that magnify specimen

Answer 11

Objective lenses

Question 12

Part of microscope that holds slide

Answer 12

Stage

Question 13

What the condenser does

Answer 13

Focuses light thro specimen

Question 14

What the iris diaphragm does

Answer 14

Controls amount of light entering condenser

Question 15

The light source on the microscope is called the

Answer 15

Illuminator

Question 16

Define magnification

Answer 16

How large something appears when compared to actual size

Question 17

Define resolution

Answer 17

Ability of light microscope to distinguish fine details (or distinguish two points a specified distance apart)

Question 18

Total magnification =

Answer 18

Magnification of ocular lens (10x) x obj lens

Question 19

Ability of subs to bend light

Answer 19

Refractive index

Question 20

Why we use immersion oil

Answer 20

Oil has same refractive index as glass, without it the light would refract and be lost

Question 21

What is a smear

Answer 21

Single layer of cells on slide

Question 22

What is does fixing mean (step in creating stain)

Answer 22

Apply heat briefly to underside of slide, attaches cells to slide

Question 23

How to create a simple stain

Answer 23

1. Create smear
2. Fixing
3. Stain
4. Rinse primary stain off and expose to mordant

Question 24

define staining (how it works)

Answer 24

When a salt dissociates into cation and anion, stain is attached to one of them

Question 25

If the pigment is attached to the cation the dye is called

Answer 25

A positive chromophore, “basic dye”

Question 26

If the pigment is attached to the anion, the dye is called

Answer 26

Negative chromophore, “acidic dye”

Question 27

What is a mordant (give example)

Answer 27

Anything that increases affinity of primary stain to cells (increases ability to stick), like heat Also coats structures (like flagella) to make easier to see

Question 28

A simple stain + several other steps used to distinguish between cell types

Answer 28

Differential stain

Question 29

Different kinds of differential stains

Answer 29

Gram stain, acid fast stain

Question 30

Describe how to do a gram stain

Answer 30

1. Primary stain, crystal violet (all steps included) apply iodine mordant 2. Add decolorizer (alcohol) to remove primary stain from some cells 3. Add counter stain safranin

Question 31

In a gram stain, the recolorized cells are gram neg or pos | Bacteria that retain the color during decolonization are

Answer 31

``` Gram negative ( lose color during decolonization ) Gram positive ```

Question 32

Acid fast stain procedure

Answer 32

1. primary stain w/ carbolfuchsin, heat applied 2. Decolorize (acid alcohol, removed red stain from bacteria that are not acid fast) 3. Counter stain (methylene blue) stains non acid fast

Question 33

Acid fast stains are used to

Answer 33

Identify mycobacterium or Norcardia bacteria, Bc have waxy material in cell wall that stain binds to

Question 34

What is a negative staining

Answer 34

Mix bacteria solution w suspension of colored particles (India ink or nigrosin) to create contrasting background, dye bacteria w simple stain (safranin) capsules won’t retain dye, appear as halos

Question 35

What a negative stain can tell us ab a bacteria

Answer 35

Presence of a capsule, therefore virulence

Question 36

What is an endospore

Answer 36

When cell detects adverse environmental conditions, forms an endospore within it that protects it from conditions

Question 37

How to endospore stain

Answer 37

1. Primary stain(malachite green), heat(stream 5min), rinse. Dyes the endospores 2. Counterstain=safranin, stains all other cell parts except endospores (pink/red)

Question 38

Why capsules of a negative stain appear as halos surrounding cells

Answer 38

Capsules don’t accept most biological dyes

Question 39

Flagella stain procedure

Answer 39

Primary stain (carbolfuchsin) and mordant applied over and over again. Layers build up on flagella like mascara

Question 40

The short the wave length of the light, the ______ the resolution

Answer 40

Greater

Question 41

Light passing thro two different materials, w two different refractive indexes, would cause the light to

Answer 41

Bend

Question 42

In an acid fast stain, the bacteria who lose color during decolorization (appear blue after recolor)

Answer 42

Are non-acid fast, lack lipid components in cell wall.

Question 43

In an acidfast stain, the bacteria that retain color during decolorization (red)

Answer 43

Are acid fast, contain lipid in cell wall (carbolfuchsin more soluble in cell walls than in acid alcohol)

Question 44

Differential stains are

Answer 44

Gram or acid fast stain

Question 45

Primary stain for acid fast stain Mordant Decolorizer Counter stain

Answer 45

Primary: carbolfuchsin (red) Mordant: heat Decolorizer: acid alcohol Counter: methylene blue

Question 46

Stains and decolorizers for gram stain in order

Answer 46

- crystal violet (primary) - iodine (mordant) - alcohol acetone (decolorizer) - safranin (counter stain)

Question 47

Special stains

Answer 47

Negative, endospore, flagella

Question 48

Which stains use safranin | Which use carbolfuchsin

Answer 48

Safranin: gram, endospore, negative, Carbolfuchsin: acid fast, flagella

Question 49

Obj power magnifications

Answer 49

Scanning= 4x Low=10x High =40x Oil= 100x

Question 50

Negative staining often uses what kind of dye

Answer 50

Acid dye

Question 51

Why gram neg bacteria lose color during gram stain (don’t retain crystal violet)

Answer 51

Alcohol disrupts outer lipopplysaccaride layer, Less peptidoglycan in cell wall, Crystal violet iodine complex washed out

Question 52

Which is harder to kill, gram positive or gram negative bacteria

Answer 52

Negative (have more impenetrable walls and an outer membrane surrounding wall)

Question 53

Why gram positive don’t lose crystal violet iodine complex

Answer 53

CV-I complex bigger than the CV molecule that entered the cell, can’t be washed out of intact thick peptidoglycan layer