Unit 2 Exotoxins And Endotoxins

Question 1

Common to all gram-negative bacteria

Answer 1

Endotoxins

Question 2

Composition: LPS of the cell envelope.

Answer 2

Endotoxins

Question 3

Released when gram-negative cell is destroyed. (requires bacterial cell death for its release)

Answer 3

Endotoxins

Question 4

Common to all gram-positive bacterla

Answer 4

Exotoxins

Question 5

Released by the living bacteria (does not require bacterial cell death for its release)

Answer 5

Exotoxins

Question 6

Can target specific host cells.
Can interrupt intracellular activities.
Can kill and help spread bacteria In tissues.

Answer 6

Exotoxins

Question 7

Organism type
Gram-positive and Gram-negative

Answer 7

Exotoxins

Question 8

Chemical nature
- Simple protein

Answer 8

Exotoxin

Question 9

Chemical nature
Protein-lipid-
polysaccharide

Answer 9

Endotoxin

Question 10

Stability to heating
- Stable

Answer 10

Endotoxin

Question 11

Stability to heating
- labile

Answer 11

Exotoxin

Question 12

Detoxification by
formaldehyde
- detoxified

Answer 12

Exotoxins

Question 13

Detoxification by
formaldehyde
- not detoxified

Answer 13

Endotoxin

Question 14

Neutralization by
homologous antibody
- Complete

Answer 14

Exotoxins

Question 15

Neutralization by
homologous antibody
- Partial

Answer 15

Endotoxins

Question 16

Biological activity
- individual to toxin

Answer 16

Exotoxins

Question 17

Biological activity
- Same for all toxins

Answer 17

Endotoxins

Question 18

Polypeptides with a molecular weight of 10,000-900,000

Answer 18

Exotoxins

Question 19

Highty antigenic: stimulate formation of high-titer antitoxin; antitoxin neutralizes toxin

Answer 19

Exotoxin

Question 20

Converted to antigenic, nontoxic toxoids by formalin, acid, heat.
and so on; toxoids are used to immunize

Answer 20

Exotoxins

Question 21

Usually bind to specific receptors on cells

Answer 21

Exotoxins

Question 22

Usually do not produce fever in the host

Answer 22

Exotoxins

Question 23

Frequently controlled by extrachromosomal genes
(eg, plasmids)

Answer 23

Exotoxins

Question 24

Lipopolysacchäride complexes; lipid A portion probably responsible for
toxicity

Answer 24

Endotoxins

Question 25

Relatively stable; withstand heating at temperatures above 60°C for hours without loss of toxicity

Answer 25

Endotoxins

Question 26

Weakly immunogenic; antibodies are antitoxic and protective; relationship between antibody titers and protection from disease is less clear than with exotoxins

Answer 26

Endotoxins

Question 27

Not converted to toxoids

Answer 27

Endotoxins

Question 28

Moderately toxic fatal for animals in tens to hundreds

Answer 28

Endotoxins

Question 29

Specific receptors not found on cells

Answer 29

Endotoxins

Question 30

Usually produce fever in the host by release of interleukin-1 and other mediators

Answer 30

Endotoxins

Question 31

Synthesis directed by chromosomal genes

Answer 31

Endotoxins