Lecture #1 - Bacterial Cytology Pt.1 Flashcards Preview

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Flashcards in Lecture #1 - Bacterial Cytology Pt.1 Deck (58):
1

what do coccus bacteria look like , give ex

round ball, staphylococcus, streptococcus

2

describe shape of coccobacillus

stubby rod, E coli

3

what does a vibrio look like

comma, vibrio cholera

4

what does a bacillus look like

long rod

5

are all bacteria the same size

no, they come in various sizes, some as small as 0.4 nanometers

6

a group of related genera is known as a

family

7

a group of related species is known as a

genus

8

a group of related strains is known as a

species

9

a set of strains within in a species is known as a ____ aka a _____

type, serotype

10

a variant of the same species is known as a

serotype

11

What is the name of the serotype of e. coli that causes disease?

"O-157"

12

t/f a serotype has huge differences between in structure between itself and the variant

false, there can be a tiny structural difference, for example only a difference in 1 sugar, but this has a huge impact

13

in gram staining the primary stain is known as

crystal violet

14

ethyl alcohol in gram staining is used to

decolorize. It will remove the primary stain from gram negative bacteria. It is not strong enough to remove the stain from gram positive bacteria.

15

what is the purpose of iodine in gram staining

it is used to "fix" the primary stain in the cell wall

16

briefly list the 5 steps to gram stain procedure

1. Have cells on slide
2. stain w/ crystal violet
3. use iodine (mordant) to fix primary stain in cell wall
4. decolorize stain with alcohol
5. counter stain with safranin

17

gram staining helps differentiate between gram ____and gram ___ bacteria

gram negative and gram positive

18

The first step that gram negative and gram positive bacteria look different is during __

decolorization. The alcohol will remove the primary stain (crystal violet) from gram negative, but not gram positive.

19

During a gram staining procedure, cells are washed with alcohol and turn clear/white. They must be...

gram negative

20

at the end of a gram staining procedure cells are purple. They must be

gram positive

21

at the end of a gram stain procedure cells are red. They must be

gram negative

22

differences in the ___ of the cell wall help to explain why gram staining works

thickness

23

what happens to the pores in peptodiglycan when it is washed with alcohol

the pores tighten. Since gram positive have a thick cell wall with lots of pores, the stain stays in it. The gram negative have hardly any peptodiglycan so the stain is easily washed away with the alcohol .

24

T/F both gram negative and gram positive bacteria have peptodiglycan

true, gram positive just has a much thicker layer than gram negative.

25

if you forget to add the mordant while doing gram staining. What color will gram positive stain

red , because iodine (the mordant) helps to fix the primary stain to the cell wall, without it the primary stain wouldn't stain.

26

A gram staining procedure is done and the cells are purple. Are they gram positive or gram negative?

Gram positive

27

A gram staining procedure is done and the cells are red. Are they gram positive or gram negative

Gram Negative

28

List two differences between gram positive and gram negative bacteria in terms of their cell wall

1. Gram Positive have teichoic acids , gram negative do not

2. Gram negative have an outer membrane, their is NO outer membrane in gram positive.

29

When looking at a cell envelope we see that it has teichoic acid in the membrane. Is it gram negative or gram positive

Only gram positive have teichoic acid

30

when looking at a cell envelope we see that there is an outer membrane. Is it gram negative or gram positive?

Gram negative. Gram positive do NOT have OUTER membranes

31

T/F all bacteria have capsules

false. Some do and its a very important virulence factor

32

in gram negative bacteria the space between the outer membrane and cytoplasmic membrane is known as

periplasmic space. There are lots of degraded enzymes found here.

33

In which region of a gram negative bacteria is peptodiglycan found in

There is a very thin layer suspended in the periplasmic space.

34

T/f bacterial cells have a singular chromosome that is covalently closed and negatively super coiled.

True!

35

What allows for the chromosome of a cell to be compacted tightly in the cell

Negative super coiling allows for this

36

What are the two main components of the cytoplasmic membrane

70% protein, 30% lipid.

37

What is one major difference in the cytoplasmic membrane between eukaryotic and bacteria cells

The cytoplasmic membrane in bacteria DO NOT have sterols ( like cholesterol) . Unlike in eukaryotes which do have sterols.

38

What is the only bacteria that does have sterol

mycoplasma

39

What is unique about mycoplasmas cell wall

They DONT have a cell wall!

40

What would happen if someone tried to treat mycoplasma with penicillin

It wouldn't have any affect because mycoplasma are unique in that there is no cell wall. Since there is no cell wall there is not target for the drug to attach!

41

T/F The only role of the cytoplasmic membrane is to transport things in and out of cell

False! It does a lot more than just that. It has a role in oxidative phosphorylation, electron transport

42

T/F periplasmic space is only found in gram negative bacteria

True! It is the space between the outer membrane and the cytoplasmic membrane.

43

what is the function of the cell wall

gives shape and structure to bacterial cells

44

what is the function of the capsule

1. allow them to avoid phagocytosis
2. allow them to stick to things (like medical eqp)

45

What are capsules typically made of

poly saccharide polymers (sugars)

46

what is unique about the capsule of bacillus anthrasis?

the capsule is made up of amino acids instead of sugars. It is made of poly d glutamic acid.

47

What is the role of glycocalyx?

loosely attached to the cell and Allows bacteria to attach to surfaces . it can coat medical equip and cause an infection

48

describe the difference between glycocalyx and the capsule

glycocalyx is loosely bound and capsule tightly bound

49

what does the term antigenic mean

Antigenic = an antigen that triggers the immune system to make anti body.

50

Capsules have K antigens T/F

True

51

T/F you can easily see the capsule of a bacteria under a microscope

You cant see capsule unless you do a capsule stain or you can make the capsule swell.

52

T/F capsules block phagocytosis

True

53

What is the role of F pilli

conjugation process, mechanism of gene exchange , mating bridge

54

_______ refers to the mechanism by which a bacteria alters its surface proteins in order to evade a host immune response.

antigenic variation. Slight changes in proteins can outsmart antibiotics

55

_____ are involved in movement and locomotion

flagella

56

What is chemotaxis

response to stimuli in the environment

57

What is the role of cytoplasmic inclusions

storage mechanisms when nutrients low in cell.

58

T/F bacteria have 80s ribosomes

False!! They have 70s made up of 50s and 30s subunits