Chapter 2 (Test 2)

Question 1

Endospores

Answer 1

Resistant to heat, chemicals, radiation, UV
Survival structures
Bacillus, Clostridium
 species
No Archaea

Question 2

Endospore conversion back to

Answer 2

to vegetative cell

Question 3

Structure of the bacterial endospore

Answer 3

Spore coats-layers of spore-specific proteins
Cortex-loose peptidoglycan
Exosporium-thin protein covering
Core-cell constituents
DNA

Question 4

Chemical constituents of the bacterial endospore

Answer 4

• Dipicolinic acid-calcium complex in core

- Small acid-soluble proteins (SASPs)

Question 5

Dipicolinic acid-calcium complex in core

Answer 5

10% of spore
Reduces water availability
Increases heat resistance
Increases chemical resistance
Intercalates in DNA 
Prevents heat denaturation

Question 6

Small acid-soluble proteins (SASPs)

Answer 6

Bind DNA—UV, desiccation, dry heat

Carbon and energy source for outgrowth

Question 7

Gliding motility

Answer 7

Filamentous or rod-shaped cells:
Cyanobacteria—Polysaccharide secreted onto surface pulls cell along
Flavobacterium—Proteins on cell surface

Question 8

Microbial taxis

Answer 8

Movement towards or away from a an agent
Cell surface receptors
Chemotaxis of peritrichously flagellated cell

Question 9

Other taxes

Answer 9

Phototaxis—light
Osmotaxis—high ionic strength
Hydrotaxis—water
Aerotaxis—oxygen