Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Unit 2 > Flashcards

Unit 2 Flashcards

1
Q

Domain bacteria are

A

Single-celled organisms
Prokaryotic
Ubiquitous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Always include what characteristics when describing bacteria

A

Morphology (shape)
Size of individual cell
Arrangement
Gram stain result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cocci (singular coccus)

A

Spheres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bacilli (singular bacillus)

A

Rods or filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Coccobacilli (singular coccobacillus)

A

Short plump rods, almost ovals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Vibrios

A

Comma-shaped (curved rod)

Singular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Spirilla

A

Rigid helix
Have flagella for motility
Singular (less common in chains)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Spirochetes

A

Corkscrew (telephone cord)
Motility: flagella to wind or by spring type creeping
Singular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pleiomorphism

A

Having more than one shape or form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The variability of bacteria can depend on

A

The health of bacteria during various stages of growth, or if growth under different conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

True or false

Always measure individual cells

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What unit are measurements of bacteria taken in

A

Microns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How to measure cocci

A

Take the diameter of the sphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How to measure bacilli

A

Give width and length of each rod

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to measure spirilla, spirochetes, and filamentous

A

Give length while it is still curved/folded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or false

Always measure the longest bacterium

A

FALSE

measure the most commonly represented size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Arrangement of cocci: singular

A

Coccus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Arrangement of cocci: diplococci

A

Pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Arrangement of cocci: streptococci

A

Chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Arrangement of cocci: staphylococci

A

Grape like clusters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Arrangement of cocci: tetrads

A

4 in a square

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Arrangement of cocci: sarcinae

A

8 coccus in a cube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Arrangement of bacilli: bacillus

A

Singles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Arrangement of bacilli: diplobacilli

A

Pairs (end to end)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Arrangement of bacilli: streptobacilli

A

Chains of 3 or more (end to end)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Arrangement of bacilli: palisades

A

“Picket fence” arranged side by side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Bacteria colony

A

Mound of bacteria cells visible to the naked eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

True or false

All cells in a bacteria colony are derived from a single bacteria cell

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Different bacteria produce colonies with distinct shapes and colors when grown in vitro, what do these characteristics help identify

A

The genus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a colony forming unit

A

The single bacterium that started a colony

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

True or false

All the cells in a colony are identical

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

True or false

Each colony represents one colony forming unit

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

A bacterial cell

A

Unicellular
Prokaryotic
Lack membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Cytoplasmic membrane/cell membrane/ plasma membrane

A

Thin flexible membrane that surrounds EVERY living cell
Selectively permeable
Contains carbohydrates, proteins and cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the main component of a cytoplasmic membrane

A

The phospholipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the proteins a cytoplasmic membrane contains (5)

A 
Channels and transporter proteins 
Signal receptor proteins 
Metabolic proteins 
Attachment proteins 
Surface antigen proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are channel and transporter proteins in a cytoplasmic membrane

A

They move substances in and out of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How do some antibiotics enter cells

A

By targeting bacteria with transporter and channel proteins to get into the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are signal receptor proteins in cytoplasmic membranes

A

Proteins that bind to signals from the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are some things a signal receptor protein may tell a the bacterium to do

A

Start or stop replicating
Move away from harm
Produce enzymes for metabolism
Produce enzymes to inactivate some antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are metabolic proteins in cytoplasmic membranes

A

Energy producing proteins located along the folds in the cytoplasmic membranes (because bacteria do not have mitochondria which are membrane bound organelles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Mesosomes

A

The folds or invagination on cytoplasmic membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are attachment proteins on cytoplasmic membranes

A

Attach bacterium to specific cells in the host
(Certain bacteria can only attach to certain cells)
Essential for infection to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are surface antigens on cytoplasmic membranes

A

Any protein on the surface of the bacteria that can be recognized by the host’s immune system
“Molecular ID tags”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What can surface antigens aid in when staining

A

Can be used to identify different strains of the same species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Functions of the cytoplasmic membrane (6)

A

Encloses cytoplasm

Barrier function

Regulates movement of molecules in/out of the cell

Interacts with environment via signal receptors

Site for energy production

Attachment

47
Q

Cytoplasm

A

The fluid that fills the cell (60-70%)

48
Q

Where is the cytoskeleton

A

Molecular scaffold that spans across the cytoplasm

49
Q

true or false

the cytoplasm is metabolically active

A

True

50
Q

Ribosomes

A

Complex structures consisting of protein and ribosomal RNA

Site or protein synthesis (where RNA is read to assemble proteins)

51
Q

What is the process of translation

A

Where RNA is read and used to assemble proteins

52
Q

Chromosomal DNA

A

A single, circular strand of DNA that contains all essential genes

53
Q

True or false

There are fewer genes in chromosomal DNA in eukaryotic cells

A

True

54
Q

Where is chromosomal DNA located

A

In the nucleoid

55
Q

What are plasmids

A

“Extra” circular pieces of DNA containing 1-2 genes (not a part of chromosomal DNA) (located outside the nucleoid)

56
Q

Are the genes located on plasmids essential to life

A

No, but they are beneficial to survival by providing advantages

57
Q

What are some advantages of some genes in plasmids

A

Proteins that provide antibiotic resistance

Genes for specific toxins or attachment proteins

Genes that enable bacteria to produce capsules

58
Q

Do all bacteria have plasmids

A

No, some have one, more than one or none

59
Q

Do plasmids replicate independently of chromosomal DNA

A

Yes

60
Q

True or false

Plasmids are very resistant to degradation and can even survive after the bacteria have been destroyed

A

True

61
Q

What are 3 ways plasmids are transferred between cells

A

Replication
Transformation
Conjugation

62
Q

Transfer of plasmids via Replication

A

When a bacteria cell divides, plasmids also duplicate and an equal number of plasmids are given to the daughter cell

63
Q

Transfer of plasmids via transformation

A

Where the cell membrane opens up and allows the cell to take up a plasmid from the environment from a bacteria that has died but the plasmid survived

64
Q

Transfer of plasmids via conjugation

A

When the direct contact between 2 bacteria cells through the creation of a temporary bridge allows the transfer of plasmids

65
Q

The cell wall surrounds

A

The cytoplasmic membrane

66
Q

Categories of cell walls

A

Gram positive
Gram negative
Acid fast

(Based on staining properties)

67
Q

The type of cell wall helps identify

A

The genus

68
Q

Functions of the cell wall

A

Maintains shape

Protects from lysis Due to osmotic pressure

Protects from toxic materials

Attachment

Prevents phagocytosis by WBCs in the immune system

69
Q

Two ways to break down the cell wall

A

Lysozymes: breaks linkages of cell wall

Beta-lactames: class of antibiotics that prevent proper synthesis of the cell wall

70
Q

Penicillin and cephalosporins are in what class of antibiotics

A

Beta-lactames

71
Q

Cell wall structure and components

A

Primary component: peptidoglycan (2 different polysaccharides linked together)

Peptide cross links: short peptide chains that link peptidoglycans together

72
Q

Gram positive wall

A

Thick: 40-90% of cell mass

20-80 layers of peptidoglycan Joined by peptide cross links

73
Q

What is transpeptidase

A

Enzyme required to make the peptide cross links in cell walls

74
Q

What is teichoic acid in the cell wall

A

Long molecules that help embed the cell wall to the cytoplasmic membrane

Also on the surface of the cell to help attach bacteria to other bacteria

75
Q

Why are gram positive bacteria susceptible to the beta-lactam class of antibiotics?

A

These antibiotics bind to and block the function of transpeptidase enzyme and prevent the formation of peptide cross links between peptidoglycan strands
(Makes susceptible to osmotic pressure lysis)

76
Q

Gram negative cell wall

A

Thin: 10% of cell mass

Only 1-2 layers of peptidoglycan

77
Q

Layers of a gram negative cell wall

A

Peptidoglycan layer: 1-2 layers, closest to cytoplasmic membrane

Outer membrane: 2 layers of lipids (inner layer is a single sheet of phospholipids, outer layer is a single sheet of lipopolysaccharides LPS)

Periplasmic space: space between the cytoplasmic membrane and outer membrane (peptidoglycan layer is in this space)

78
Q

What are lipopolysaccharides

A

The molecule that makes up the outermost layer of a gram negative cell wall (part of the outer membrane)

79
Q

What are lipopolysaccharides important for?

A

To bacteria: establishing infection

To host: to fight infection

80
Q

What are the 3 parts of a lipopolysaccharide

A 
O-antigen 
Core polysaccharide 
Lipid A (endotoxin)
81
Q

What is the O-antigen on lipopolysaccharides

A

Repeats of polysaccharide units (hydrophilic)

Smooth: bacteria with long chains

Rough: bacteria with short or no chain

82
Q

True or false

Some species or strains are distinguishable by the sugar molecule in their o-chain (gram negative wall)

A

True

83
Q

Why are the O antigens on gram negative cell walls important for bacteria to establish infection?

A

WBCs unable to grab onto smooth bacteria

Aid in attaching to epithelial cells

Some bacteria can alter the sugars that make the O-antigen: can evade the immune system

84
Q

The immune system can recognize sugars in the O antigen when fighting infection, what happens

A

The immune system targets these for destruction

The O chain will trigger non-specific inflammation

85
Q

Lipid A (AKA endotoxin)

A

The tail of lipopolysaccharides made of lipid chains

They are the same in all gram negative bacteria

Hydrophobic

Holds lipopolysaccharide in place

86
Q

True or false

Lipid A is one of the strongest activators of inflammation

A

True

87
Q

Endotoxic shock

A

Condition where excess inflammation causes blood vessels to dilate, drop blood pressure, and cause systemic shock
Caused by a release of large amounts of lipid A during gram negative infection
Can be fatal

88
Q

Why can endotoxic shock never happen in gram positive bacteria

A

Gram positive cell walls do NOT contain lipopolysaccharides (which have lipid A) only gram negative cell walls do

89
Q

Why do some bacteria do not gram stain?

A

They have no cell wall structures similar to gram positive and negative walls

90
Q

Acid fast bacteria

A

Their cell wall is similar to gram positive but contain large amounts of mycolic acid (waxy) (long chain of fatty acids)

Ex. Mycobacterium

91
Q

Mycoplasma

A

Do not have cell walls
Plasma membrane more resistant to osmotic pressure
Very pleiomorphic

92
Q

What does the Periplasmic space contain

A

Proteins to digest macronutrients

Proteins to break down toxic compounds before the cross the plasma membrane

Synthesis and storage of pathogenic factors

93
Q

Flagella

A

Threadlike projections that allow motility

All spirochetes and spirilla have them

94
Q

What does the immune system recognize in flagella

A

The proteins that make the flagella (act as antigens)

95
Q

Location and number of flagella on a bacterium determine

A

Type and speed of movement

96
Q

Bacteria with many flagella that move together tend to be

A

Faster

97
Q

True or false

You can see the flagella on bacteria

A

False

But you can see fast motility

98
Q

Benefits of motility on bacteria

A

Can move towards supportive environments

Can move away from harmful substances

99
Q

Flagella movement

A

Fastest

Flagella acts as a propeller to swim through lipids

100
Q

Spirochetes motility

A

Corkscrew motion due to Periplasmic flagella (specific to Spirochetes)

101
Q

Twitching motility

A

Mediated fimbriae, crawling on surface or through lipids

102
Q

Gliding motility

A

Pushed by slime made by the bacteria

103
Q

Chemotaxis

A

Process of identifying and then moving away from a chemical via receptors that tell the bacteria what to do

104
Q

Positive chemotaxis

A

Moving towards attractants

105
Q

Negative chemotaxis

A

Moving away from repellants

106
Q

Fimbriae (singular fimbria)

A

Short, thin, hair like protein structures that extend out of the cell wall

Primary function: attachment to surfaces

107
Q

Pili

A

Very large protein structures that extend from cell wall

2 functions:
Attachment
Forms connection during conjugation

108
Q

Capsules

A

Polysaccharide secreted around the cell wall
Sugar units well organized
Attached to cell, not easily removed

Primary functions:
Resistance/protection (from drying out)
Attachment

109
Q

Slime layers

A

Polysaccharide secreted around the cell wall
Sugar units are not uniform, loose coating, easily removed

Primary functions:
Resistance/protection 
Attachment
Motility
formation of biofilms
110
Q

Advantages of capsules and slime layers (5)

A

Resistance to phagocytosis and bacteriophages

Protection from drying out

Protects from detergents and antibiotics

Attachment

Motility (slime)

111
Q

Biofilms

A

Communities of bacteria (and yeast) embedded in a matrix that attach to a surface

Single or hundreds of different species of bacteria

Matrix sticks microbes to one another and onto a surface (usually moist)

112
Q

4 steps in biofilm formation

A

1) cell attachment to surface (by receptors, flagella, fimbriae)
2) cell produces exopolysaccharides (outside cell)
3) biofilm matures (increase in size and number)
4) cells from biofilm disperse and can reattach elsewhere

113
Q

Where are biofilms common to?

A 
Standing water
Rough surfaces 
Surgical implants 
Catheters 
Heart valves
Teeth
114
Q

Biofilms are self-sustaining so they are

A

Hard to treat with antibiotics or disinfectants

Microbiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions