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Flashcards in Price Lectures Exam 1 Deck (40)
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1

Infectious vs. contagious

Infectious--disease caused by living organism
Contagious--spreads from host to host
**All contagious diseases are infectious, but not vice versa**

2

Disease carrier

organism that appears healthy but is shedding the virus

3

What is virulence?

ability of organism to cause disease

4

what is LD50? how does it relate to virulence?

LD50 is number of organisms needed to kill 50% of population;
a LOWER LD50= MORE virulent

5

What does it mean if an organism is a facultative anaerobe?

is fine with or without oxygen

6

The cell envelope consists of all layers outside the _____

cytoplasm

7

What is the outer most layer of the envelope?

capsule

8

What is the significance of the capsule? (2)

1) antiphagocytic (new infections)
2) important for serotyping

9

When using the capsule for serotyping, what is the identifying structure?

K antigen

10

Glycocalyx vs. slime layer? Function(s) of each?

Glycocalyx--> TIGHTLY bound onto capsule; for adherence

Slime layer-->LOOSELY bound; adherence and antiphagocytic

11

Are flagella unique to gram positive or negative?

No; can be found or absent in either

12

Important antigen of flagella?

H antigen

13

What is phase variation?

Bacteria can change protein sequence of flagella to "hide" from antibodies made against original sequence

14

What is Conjugation? What type of gene transfer is it?

exchange of genetic information using sex pilus;
horizontal gene transfer

15

In conjugation, which cell produces the sex pilus?

the donor cell

16

Which bacterial family lacks peptidoglycan?

Mycoplasma

17

What two molecules alternate to make up the peptidoglycan backbone?

NAG and NAM

18

The composition of which component of the peptidoglycan varies between spp?

tetrapeptide chain

19

What are permeases?

proteins that regulates movement in and out of the cell (located in cytoplasmic membrane)

20

Location of hydrolytic enzyme secretion:
1) Gram +
2) Gram -

1) into external medium

2) periplasmic space

21

Detergents, polymyxins, and ionophores all target what bacterial structure?

cytoplasmic membrane

22

2 reasons plasmids are relevant?

1) can encode antibiotic resistance
2) can encode virulence factors (i.e. toxins)

23

tecichoic acids and endospores are unique to?

Gram positive bacteria

24

3 functions of techoic acids?

1) bind Mg2+
2) autolysis
3) protection from antimicrobial peptides

25

Name 4 structures unique to gram negative bacteria?

1) Lipoprotein
2) Outer membrane
3) Lipopolysaccharide (LPS)
4) periplasmic space

26

Function of lipoprotein?

anchors outer membrane to peptidoglycan

27

Function of outer membrane?

protects cell from host environment

28

Name the 3 major abundance proteins found in outer membrane

1) Matrix porins
2) specific porins
3) Non-porin OM proteins

29

Name the 3 portions of LPS

1) Lipid A
2) Core polysaccharide
3) O-specific polysaccharide (O antigen)

30

This portion of LPS is the "endotoxin"

Lipid A

31

Which portion of LPS shows the most variation between spp and confer antigenic specificity?

O-antigen

32

Bacteriostatic vs. bacteriocidal

bacteriostatic--reversibly alters growth
bacteriocidal--irreversibly inhibits growth

33

What are the 4 mechanisms of antibiotics

inhibit cell wall synthesis
inhibit membrane function
inhibit protein synthesis
inhibit nucleic acid synthesis

34

Penicillins, cephalosporins, bacitracin, cycloserine, vancomycin, and carbpenems mode of action?

inhibit cell wall synthesis

35

Polymyxins, amphotericin B, ketoconazole, ionophores mode of action?

inhibit cell membrane function

36

Which drug is anti-fungal?

Amphotericin B

37

Aminoglycosides, tetracyclines, chloramphenicol, erythromycin, and clindamycin mode of action?

inhibit protein syntesis

38

Which drugs target the SMALL ribosome subunit?

aminoglycosides and tetracyclines

39

which drugs target the LARGE ribosome subunit?

chloramphenicol, erythromycin, and clindamycin

40

Fluoroquinolones, rifampin, sulfonomides, trimethoprim, and metronidazole mode of action?

inhibit nucleic acid synthesis