Brainscape's Knowledge GenomeTM

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


See full index

1 PID Unit > 4 lecture peptidoglycan synthesis and antibiotics > Flashcards

4 lecture peptidoglycan synthesis and antibiotics Flashcards

1
Q

what blood pressure is considered to be hypotensive?

A

Any systolic blood pressure below 90/x is considered hypotension.

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

what is macular erythroderma?

A

a skin condition characterized by flat reddened skin.

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

what is the number one thing you do for a septic patient to control their blood pressure?

A

give them fluids and electrolytes.

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

If you take cultures and find out that the bacteria you are dealing with is MRSA, what antibiotic do you quickly give?

A

1) vancomycin

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

What does CA-MRSA mean? What toxin does it release?

A

1) Community associated Methacillin resistant S. Aureous.2) The toxin it releases is enterotoxin C

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

Why would you ever give IVIG’s?

A

During sepsis with excess superantigen release. IG’s bind up the Toxin.

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

The peptidoglycan wall is bound by which two types of covalent bonds?

A

1) glycosidic2) peptide

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

what happens to bacteria that do not have an intact cells wall?

A

they lyse due to turgor pressure

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

When does peptidoglycan synthesis/hydrolysis occur in normal bacterial cultures?

A

during cell division

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

T/F Peptidoglycan is unique to bacteria?

A

True. (many antibiotic targets)

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

Where is the gram - peptidoglycan layer located?

A

within the periplasm

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

what percentage of gram + peptidoglycan is cross linked? Gram -?

A

1) 75%2) 25%

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

what is the reason for the decreased cross linking in gram - bacteria compared to gram +?

A

It is because the peptidoglycan of a gram - bacteria is partially covalently bound to lipoproteins.

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

what kind of covalent bond binds NAG to NAM?

A

Beta 1-4 glycosidic bond

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

how do you make NAM?

A

NAG + lacteal group

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

what group carries the tetrapeptide with alternating L and D amino acids?

A

The NAM is the polysaccharides that carries the four amino acids. Therefore, it is the where the cross linking is occuring. NAM to NAM

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

What makes the peptide cross link that connects the 4th amino acid of one NAM to the 3rd amino acid of another NAM?

A

5 glycine residues

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

To make NAG into Nam, where does the lacteal group have to be attached?

A

The lacteal group attaches to the C3 carbon

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

T/F Only MA carries the tetrapeptide chains?

A

True. Recall that MA=NAM

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

What is so significant about the D amino acids in the bacterial cell wall?

A

The body cannot breakdown/process D amino acids and they are only found in bacteria.

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

Which amino acids make up the tetrapeptide link?

A

1) L-alanine2)D-Glutamate3)L-lysine or diaminopimelic acid4)D-alanine

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

Penicillin and cephalosporin do what?

A

They block the enzymes that form the crosslink between the 3rd and 4th amino acid that is connected to NAM. This disrupts the formation of peptidoglycan.

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

Where does Vancomyocin function?

A

Vancomyocin binds to the 5 amino acid chain of NAM and prevents the transpeptidase reaction. This prevents the cross linking.

24
Q

What are PBP’s?

A

Penicillin binding proteins

25
Q

how many PBP’s does E.coli have? S. Aureus?

A

E. Coli= 6S. Aureus=4

26
Q

where does synthesis of peptidoglycan begin?

A

in the cytoplasm

27
Q

fructose-6-phosphate is the sugar base for which compound in peptidoglycan synthesis?

A

UDP-NAG

28
Q

PEP enzyme helps with the conversion of NAG to NAM. What is the antibiotic that inhibits this enzyme by acting as an analog?

A

phosphonomycin

29
Q

what is the name of the carrier lipid that carriers UDP-NAM to the outer peptidoglycan structure?

A

Undecaprenol phosphate (AKA Bactoprenol)

30
Q

what does bacitracin do to stop bacterial cell wall synthesis?

A

it inhibits the regeneration of BP from BPP. Recall this is the carrying lipid.

31
Q

How is cross linking of the peptidoglycan wall carried out?

A

Through transpeptidation. It does it through displacing the terminal D-alanine.

32
Q

How do all beta lactam antibiotics work?

A

They prevent transpeptidation of the peptidoglycan.

33
Q

what does lysozyme do to bacteria?

A

it hydrolyses the glycosidic linkages of peptidoglycan.

34
Q

Name 3 specific bacteria that you would not use antibiotics to destroy the peptidoglycan wall?

A

1) mycoplasma (no cell wall)2) mycobacterium (very thick/tough cell wall)3) chlamydia

35
Q

How does the antibiotic cycloserine work?

A

It prevents the formation of UDP-NAM(aa5) form UDP-NAM(aa3). So it prevents the addition of the last two D-alanines

36
Q

T/F Group A strep are 10X more sensitive to bacitracin than most other bacteria?

A

Yes. This helps to differentiate Group A strep.

37
Q

What characteristics define Group A strep?

A

Gram + coccichainsCatalase NegativeBacitracin sensitive

38
Q

T/F Bacitracin should be taken orally when you have a known enteric Group A strep infection?

A

False.Bacitracin is topical only. Ingestion is toxic.

39
Q

Augmentin is made from 2 drugs which are?

A

1)Amoxicillin2) Clavulanic acid

40
Q

what is the defining chemistry of a bata lactam antibiotic?

A

a four sided ring with one Nitrogen and 3 carbons.

41
Q

Some beta lactams have a sulfer atom attached which can induce what in the body?

A

Type 1 hypersensitivity reactions.

42
Q

What do beta lactam antibiotic bind to?

A

they bind to the penicillin binding proteins (PBP)

43
Q

T/F PBP’s are associated with transpeptidation reactions?

A

True. Recall this is the target of Beta lactams.

44
Q

What leads to beta lactam resistance such as penicillin resistance?

A

If the bacteria replaces the normal PBP with PBP2a you get antibiotic resistance to the beta lactams.

45
Q

T/F penicillins normally target gram + bacteria?

A

True. However, there are some that can extent to hit gram (-) as well.

46
Q

T/F Augmentin is considered a broad spectrum antibiotic?

A

true

47
Q

T/F Penicillin is considered a narrow spectrum antibiotic?

A

True

48
Q

Where did Beta lactams come from?

A

molds originally

49
Q

T/F Carbapenems and penems are the most narrow type of beta lactam antibiotics?

A

False. They are the most broad and is why they are frequently used.

50
Q

T/F you would give cephalosporin to help kill MRSA?

A

False. MRSA is resistant so you would have to use vancomycin.

51
Q

T/F Monobactums contain a nucleus and a beta lactam ring?

A

true. They are a single (mono) lactam ring structure with no other fused rings.

52
Q

What is the purpose of a Beta lactamase inhibitor?

A

They minimally help stop the breakdown of Beta lactams allowing the antibiotic effects to work better. Released from bacteria.

53
Q

What toxin does CA-MRSA strain USA400 make?

A

Enterotoxin C

54
Q

What decreases the cross linking of peptidoglycan in gram neg. bacteria?

A

Being covalently bound to lipoproteins

55
Q

Streptococcus pyogenis falls into which group?

A

Group A strep

56
Q

What is the most commonly used beta lactamase inhibitor?

A

Clavulanic acid

1 PID Unit (12 decks)

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