Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cells to Organisms - Lectures > Lecture 7. Bacterial Cell Envelope Part 2. > Flashcards

Lecture 7. Bacterial Cell Envelope Part 2. Flashcards

(42 cards)

Start Studying
1
Q

What is beyond the outer membrane and cell wall ?

A
  1. Capsules, EPS and biofilms
  2. S-layers
  3. Fimbriae and pili
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does EPS stand for ?

A

Extra cellular polysaccharides

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

What do capsules, EPS and biofilms have in common ?

A
  1. Outermost layer of protection
  2. Common structure, biogenesis and export pathways
  3. Assists in adhesion and solid surfaces
  4. Protects against antibiotics, antimicrobial peptides and host immune responses
    5
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where are capsule polysaccharides retained ?

A

On cell surfaces

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

What happens to EPS ?

A

They are secreted

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

What happens to biofilms ?

A

Product of multiple extra cellular bacteria producing EPS

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

What is a capsule ?

A

A type of glycocalyx

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

What is meant by distinct, gelatinous ?

A

Capsule

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

What is meant by slime layer ?

A

Irregular, diffuse

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

What does a capsule have in terms of water ?

A

High water content

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

What is the capsule important for ?

A

Virulence – resists phagocytosis

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

What is the function of capsule ?

A
  1. Barrier to toxic hydrophobic molecules
  2. Protection against dessication
  3. Resistance to bacteriophage
  4. Evade host defences
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does a capsule that avoids detection do ?

A

Hide surface structures – resist phagocytosis

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

What does a capsule do to avoid destruction ?

A

Prevent complement-mediated lysis

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

Where are opsonins directed to ?

A

Cell envelope components are deposited beneath the capsule layer

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

What is an opsonin ?

A

Substances that bind to foreign micro-organisms making them more susceptible to phagocytosis

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

What does capsule do to opsonin ?

Study These Flashcards
A

Inhibits access

18
Q

What often are invasive bacterial pathogens ?

19
Q

What are EPS important for ?

Study These Flashcards
A

The structure and function of biofilms

20
Q

What are bacteria in biofilm ….

Study These Flashcards
A
  1. Impervious to phagocytosis by neutrophils and macrophages
  2. Resistant to antimicrobial peptides and complement
  3. Semi-dormant - difficult to inhibit with antibiotics
21
Q

What are biofilm associated infections ?

Study These Flashcards
A
  1. S. aureus

2. S. epidermis

22
Q

What does Pseudomonas aeruginosa biofilms do ?

Study These Flashcards
A

Cause cystic fibrosis in lung infections

23
Q

What is a s-layer ?

Study These Flashcards
A

Extracellular layer coating the entire bacterial cell surface

24
Q

Where are s-layers found ?

Study These Flashcards
A
  1. Gram positive bacteria
  2. Gram negative bacteria
  3. Archaea
25
What are s-layers composed of ?
Protein or glycoprotein
26
What is the structure of s-layer ?
1. Protein subunits come together to form selection of arrays 2. Porous mesh 3. Protective barrier 4. Selective permeability
27
What are the functions of s-layer ?
1. Molecular sieve 2. Protection 3. Adherence to host cell surfaces
28
What are pili made of ?
Pilin protein
29
What are the two types of pili ?
1. Sex pili | 2. Ordinary pili
30
What do pili do ?
1. Attach to other bacteria | 2. Motility
31
Where are pili mostly found ?
Gram negative bacteria
32
What type of pili are found in P. aeruginosa ?
Type 4 pili
33
What do type 4 pili do ?
1. Adherence to surfaces 2. Biofilm formation 3. Twitching motility 4. Senses initial contact with surfaces
34
What are fimbriae ?
Bristle like fibers present in large numbers
35
What do fimbriae do ?
Help attach cells to a solid surface or tissues
36
What do fimbriae do to bacteria?
Help bacteria cling together
37
Where are fimbriae found ?
Gram negative and gram positive
38
Where do fimbriae recognise host molecules ?
Adhesin present at tip
39
What is the structure of fimbriae in E.coli ?
1. FimH tip protein - adhesin 2. 3nm thick tip fibrillum composed of 2 proteins 3. 7nm thick helical rod--subunits of fimA
40
What are virulence factors during bladder infection ?
Type 1 fimbriae fimH and P fimbriae
41
Where do fimbria adhere to in bladder infection ?
Uroepithelial cells of baldder
42
What is the receptor in bladder infection ?
Mannose containing glycoproteins

Cells to Organisms - Lectures (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions