Module 3 Flashcards

(93 cards)

1
Q

Cocci

A

spherical

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

Bacilli

A

rod shaped

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

Vibrio

A

curved rod

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

Spirilla

A

rigid helices

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

Spirochetes

A

flexible helices

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

Mycelium

A

multinucleated filamen

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

Pleomorphic

A

variable in shape

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

Diplococci

A

2 spheres

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

Streptococci

A

chain of spheres

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

Staphylococci

A

cluster of spheres

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

Tetrads

A

groups of 4 (cube)

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

Sarcinae

A

groups of 8 (cube)

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

Coccobacilli

A

short rods

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

What is the plasma membrane?

A
  • membrane that encompasses the cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 4 functions of the plasma membrane?

A
  1. separates cell from its environment
  2. selectively permeable barrier
  3. location of vital metabolic processes
  4. detects and responds to chemicals in surroundings with the aid of receptor molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are integral proteins, what is their function and where are they found?

A
  • protein that passes through both layers of the cell membrane
  • acts as a transport channel
  • found in cell membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the different between a peripheral membrane pr- and an integral pr-?

A

integral pr- DOES pass through membrane whereas other one DOESN’T

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

What does an peripheral membrane protein do?

A

regulates signaling

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

What are Membrane Lipids composed of?

A
  • composed of polar and non-polar ends, making it amphipathic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the polar ends of the membrane lipids

A

They are the head of the lipid and are hydrophilic, meaning they interact with water

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

What are the non-polar ends of the membrane lipid

A

They are the tail of the lipid and are hydrophobic, meaning they stay away from water

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

What are bacterial membranes

A

highly organized, asymmetric, flexible, dynamic membranes

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

How do bacterial membranes differ from eukaryotic membranes

A

bacterial membranes lack sterols and instead contain hopanoids

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

What are hopanoids?

A

Sterol-like molecules that stabilize the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the bacterial cell wall
- rigid structure outside the plasma membrane
26
What are 3 functions of the bacterial cell wall?
1. provides characteristic chape to cell 2. protects the cell from cell explosion (osmotic lysis) 3. can contribute to pathogenicity
27
What is peptidoglycan?
mesh-like polymer composed of identical subunits
28
What is in peptidoglycan?
- several different amino acids - chains of linked peptidoglycan subunits which are crosslinked by peptides
29
What are 3 things found in Gram (+) cell walls
- primarily peptidoglycan - large amounts of teichoic acids - some bacteria have layer of pr- on the surface of the peptidoglycan
30
What are teichoic acids and what is their function?
- polymers of glycerol or ribitol joined by phosphate groups - play a role in maintaining the cell wall structure
31
What is the periplasmic space
space that lies between plasma membrane and cell wall
32
what are exoenzymes?
enzymes secreted by gram (+) bacteria
33
what happens when something remains in the periplasmic space?
usually attaches to the plasma membrane
34
what are exoenzymes similar to and why?
periplasmic enzymes found gram (-) bacteria because they perform many of the same functions
35
what is a role of the periplasmic space?
degrading nutrients for transport across the membrane
36
What is found in gram (-) cell walls?
- thin layer of peptidoglycan - surrounded by an outer membrane - large periplasmic space
37
What is the outer membrane of a gram (-) cell composed of?
Lipids, lipoproteins, and lipopolysaccharides
38
Can teichoic acids be found in gram (-) cell walls?
NO
39
True or False: Gram (-) cell walls are more complex than gram (+)
TRUE!
40
What is the purpose of Braun's lipoproteins?
connects outer membrane to peptidoglycan in a gram (-) cell
41
Is the periplasmic layer the same in both gram (+) and gram (-) cells? why or why not?
No, the gram (-) has a much larger periplasmic space with many enzymes present
42
What are 5 roles of Lipopolysaccharides (LPS)?
- protection from host defenses (O side chain) - contributes to the (-) charge on cell surface - helps stabilize the outer membrane structure - may contribute to surface attachment and biofilm formation - aids in creating a permeability barrier
43
What lipid can act as a toxin?
Lipid A
44
Why is the outer membrane more permeable than the plasma membrane?
due to the presence of porin and transporter pr-
45
What do porin pr- do?
form channels through which small molecules (600-700 daltons) can pass
46
What is Osmotic lysis?
when the liquid outside a cell moves inside, causing it to burst (the movement of water causes swelling and lysis due to osmotic pressure)
47
When can Osmotic lysis occur?
when cells are in hypotonic solutions
48
How does the cell wall protect against osmotic lysis?
- lysozyme breaks the bond between the N-acetyl glucosamine and N-acetylmuramic acid - penicillin inhibits peptidoglycan synthesis
49
Where are intracytoplasmic membranes observed?
- in many photosynthetic bacteria - in prokaryotes with respiratory activity
50
What are Mesosomes and what is their function?
- plasma membrane infoldings - function not agreed upon
51
What are capsules?
- sticky outer later usually composed of polysaccharides - well organized and not easily removed from cell
52
What are slime layers and what makes them different from capsules?
similar to capsules except they diffuse, they're unorganized and easily removed from cell
53
What is Glycocalyx?
network of polysaccharides extending from the surface of the cell
54
what can slime layers or capsules also be referred to as?
Glycocalyx IF they're composed of polysaccharides
55
What are S-Layers?
regularly structured layers of protein or glycoprotein
56
In bacteria, the S layer is ________ to the cell wall
external
57
Are S-layers uncommon in Archaea
NO - they're quite common
58
What are the 3 main functions of Capsules, Slime Layers, and S-Layers
1. facilitate attachment to surfaces 2. protection 3. facilitate motility of gliding bacteria
59
What are 3 examples of protection that capsules do?
protection from: - host defenses - harsh environmental conditions - viral infection or predation by bacteria - chemicals in environment - osmotic stress
60
Archaeal Membranes contain ________ linkages instead of ________ linkages
ether, ester
61
What is a distinctive feature of Archaea?
Membrane lipids
62
How many layers in Archaeal Membranes?
some are monolayer instead of bilayer (can be both)
63
What do Archaeal cell walls consist of and what do they lack?
- they lack peptidoglycan - usually consists of complex heteropolysaccharides
64
Methanogens have walls containing ____________
pseudomurein
65
What is the cytoplasmic matrix?
substance in which the nucleoid, ribosomes and inclusion bodies are suspended
66
What are the 3 main functions of the cytoplasmic matrix?
1. plays a role in cell division 2. pr- localization 3. determination of cell shape
67
What are 3 features of the cytoplasmic matrix
- mostly water - lacks membrane-bound organelles - major part of the protoplasm
68
What is the protoplasm
plasma membrane + everything within
69
What are inclusion bodies?
granules of organic and inorganic material that are stockpiled by the cell for future use
70
What are the components of an inclusion body?
- enclosed by a single layered membrane - membranes vary in composition (pr-, lipids)
71
What are ribosomes and what is their function?
- complex structures consisting of proteins and RNA - function: site of protein synthesis
72
What is the Nucleoid and what does it contain?
- irregularly shaped region in the cytoplasm - contains chromosomes
73
Is the nucleoid membrane bound?
no
74
What are chromosomes?
- closed, circular, doubled stranded DNA molecule - looped and coiled extensively
75
What are plasmids?
small, closed circular DNA molecules - similar to chromosomes
76
What are 2 differences between plasmids and chromosomes?
1. plasmids are much smaller than chromosomes 2. chromosomes contain essential genes for survival whereas plasmids contain advantageous genes
77
What is curing
the loss of a plasmid
78
What are Fimbriae and what is their function?
- short, thin, hairlike proteinaceous appendages - function: mediate attachment to surfaces, can be required for twitching or gliding motility
79
What type of Fimbriae is required for twitching or gliding motility?
type IV Fimbria
80
What is Sex Pili and what is their function?
- to fimbriae except longer, thicker and less per cell - required for mating
81
CCW Flagellum rotation = __________
forward motion (run)
82
CW Flagellum rotation = ___________
disrupts run, causing a tumble
83
monotrichous
one flagellum
84
polar flagellum
flagellum at the end of cell
85
amphitrichous
one flagellum at each end of cell
86
lophotrichous
cluster of flagella at one or both ends
87
peritrichous
spread over entire surface of cell
88
Name and explain 2 other types of motility:
1. Spirochetes - exhibit flexing and spinning movements of axial filaments which are composed of flagella 2. Gliding Motility - cells coast along solid surfaces
89
What is chemotaxis?
movement towards a chemical attractant OR away from a chemical repellant
90
What do chemoreceptors do?
detect concentrations of attractants or repellents
91
In the presence of an attractant:
- tumbling down - runs in direction of attractant up
92
What is bacterial endospore?
- formed by gram (+) bacteria - resistant to numerous environmental conditions
93
What are 4 things the bacterial endospore is resistant to?
- heat - radiation - chemicals - desiccation