Foundational Microbiology 2

Question 1

is the ability of a lens to separate or distinguish between small objects that are close together

Answer 1

resolution

Question 2

Consider the limits of theta

Answer 2

90 degrees

Question 3

oil immersions change the refractive ___

Answer 3

index

Question 4

air has a much ____ refractive index than glass. Glass has an equal refractive index to oil

Answer 4

less

Question 5

With ____: you are maximizing the amount of light beams that end up reaching the objective lens (the light you can eventually see)

Answer 5

oil

Question 6

We want to decrease d by:

Answer 6

• using smaller wavelengths
• increasing theta
• increase n (refractive index) by using an oil immersion
  BUT STILL… at best, you can get 0.2 m of resolution

Question 7

Dark-Field Microscopy

Answer 7

• Use peripheral beams
• The background is dark and specimens are light

Question 8

Phase Contrast Microscopy

Answer 8

2 different populations of light
- The light that passes through the specimen
- Light that does not pass through the specimen

Able to see the structure of the cell but also structures within the cell
- Good for studying motility, detailed structures, organelles, complex structure

Question 9

Differential Interference Contrast (DIC) Microscopy

Answer 9

Creates the illusion that the structures are 3D

Question 10

Fluorescent Microscopes

Answer 10

Almost the reverse of what we’ve been talking about
The light source is from the side - high energy, short wavelengths

Question 11

The solution: Confocal Scanning Laser Microscopy (CSLM)

Answer 11

Allows you to take a picture of a specific focal plane without getting any of the background information

Question 12

Different vs light and electron

Answer 12

We use an electron gun instead of a light or lamp source
For light: when we want to manipulate the light - we use glass
For electrons: we use magnets to manipulate
BENDS THE BEAM
- Electrons - have a higher energy curve - more likely to pick things up

Question 13

sphere

Answer 13

Coccus

Question 14

rod

Answer 14

Bacillus

Question 15

curve

Answer 15

Virbrio

Question 16

Binary fission

Answer 16

1. chromosome replication begins
2. repication continues
3. two copies go to opposite sides
4. replication finishes
5. two daughter cells results
   the daughter regular chromosomes are stuck in opposite sides of the cell

Question 17

Bacterial Reproduction

Answer 17

The new origins of replication move apart, towards opposite ends of the cell. A septum (wall) forms down the middle of the cell, partitioning it into two new cells, each with one of the two (now complete) bacterial chromosome copies. The cell pinches in two. We now have two new bacteria!

Question 18

will break off and give rise to new filaments

Answer 18

spores

Question 19

budding

Answer 19

1. DNA is replicated
2. one daughter DNA molecule is moved into bud
3. young bud starts
4. daughter cell buds off

Question 20

strepto-

Answer 20

repeating segment

Question 21

Tetrads

Answer 21

square of four cells

Question 22

Sarcinae

Answer 22

8 cells in a cube

Question 23

Staphlococci

Answer 23

random plane - just a grouping

Question 24

Arrangement of bacteria: Cocci
is based on:

Answer 24

1. Plane of cell division
2. Do they stick together after division or not

Question 25

arrangement of bacteria: bacilli

Answer 25

Only able to divide on their short axis

Question 26

Palisade

Answer 26

stick together

Question 27

V-shape

Answer 27

from snapping

Question 28

two types of external structure (glycocalyx)

Answer 28

1. capsule (packed together) 2. slime layer Loosely packed Slimy = they get stuck on teeth etc. and capsules are unrecognizable to the immune system (pneumonia-causing bacteria)

Question 29

Peritrichous

Answer 29

flagella all over

Question 30

Single Polar Flagellum

Answer 30

one on one side

Question 31

Tuft of polar flagella

Answer 31

tuft of flagella on one side

Question 32

How flagellated bacteria move: A biased random walk

Answer 32

Tumble: all flagellum are beating randomly - spin around in a random direction THEN Run: all flagellum are operating at the same time in the same coordinated motion If the run is the wrong direction, they will tumble again, If the run is in the right direction, the run will be longer

Question 33

chemotaxis and phototaxis

Answer 33

tumble THEN run - towards light or chemicals (scent)

Question 34

Rod-like extensions - like grappling hooks

Answer 34

Fimbriae Adhere to eachother and things in their environment Disease-causing - affectability to adhere to host (especially if they lack the Slimy layer)

Question 35

Pili

Answer 35

allow cells to connect and exchange nucleic acids with one another If one has antibiotic resistance - it can be exchanged with another

Question 36

Peptidoglycan

Answer 36

major structural polymer in most bacterial cell walls

Question 37

Gram negative cell walls

Answer 37

Have an thin peptidoglycan cell wall (inner membrane) which is like the PM Then a Outer membrane surrounding that Harder to disrupt - medications usually target the cell wall however, there is an additional structure protecting it

Question 38

Lipopolysacchardie in cell wall

Answer 38

Lipid A in this Lipopolysaccharide is very toxic and can cause shock and fevers in humans Killing these molecules would therefore release this toxin - sometimes better just to deal with the general symptoms

Question 39

Gram-positive

Answer 39

has no outer membrane, thicker cell walls

Question 40

gram-positive cells remain ___

Answer 40

purple

Question 41

gram-negative cells are _____

Answer 41

pink

Question 42

Decolourizing agent

Answer 42

breaks down thin cell wall of gram negatives, causing stains to be washed away

Question 43

what Gram positive bacteria have very waxy cell walls that reject crystal violet

Answer 43

Mycobacterium and Nocardia

Question 44

The Ziehl-Neelsen acid-fast staining technique was used instead

Answer 44

Acid-fast bacteria – pink/red Non-acid-fast - blue

Question 45

some bacteria can form endospores. This allows them to withstand ____

Answer 45

harsh conditions - go into hibernation