Appendages and Internal Structure

Question 1

What are the function of capsules and slime layers?

Answer 1

Attach to surfaces
Protect from phagocytosis

Question 2

Capsule vs Slime layer

Answer 2

Capsule more well-organized, pressed against the cell, and protects better against phagocytosis
Slime layer are not closely attached to the cell, they are used to form biofilms

Question 3

What can block capsule development?

Answer 3

Cyclic polysaccharide

Question 4

What is flagella made up of?

Answer 4

Filament, hook, shaft, and basal body

Question 5

What is basal body made up of?

Answer 5

Bushing (reduces friction)
Stator (generates torque)
Rotor (does rotation)

Question 6

How is flagellum built?

Answer 6

Flagellin is exported from the cytoplasm through a type III protein export apparatus

Question 7

How does flagellum move?

Answer 7

PTM; H+ move through stator. Torque is transmitted to the rotor.

Question 8

What is chemotaxis?

Answer 8

Descriptor for flagellum movement. Bacteria move towards chemoattractants

Question 9

What is “run” mode?

Answer 9

C-ring has counterclockwise rotation, bacteria move in one direction

Question 10

What is “tumble” mode?

Answer 10

C-ring has clockwise rotation, flagellum move in different direction, bacteria “tumbles”

Question 11

What structure is the C-ring part of?

Answer 11

Stator

Question 12

Function of pili

Answer 12

Attachment to surfaces
Motility
Electron transfer between cells

Question 13

Methods of motility using pili

Answer 13

Gliding
Twitching

Question 14

What are nanowires?

Answer 14

thin, long tubular extension of cell membrane that extends from one cell to another that allows sharing of nutrients and electrons

Question 15

What do bacteria use for storage? What do they store?

Answer 15

Granules can store carbon, phosphate, or sulfur

Question 16

What form is carbon stored in bacteria?

Answer 16

glycogen granules, PHB, or PHA granules

Question 17

What form is phosphate stored?

Answer 17

Volutin, acts as energy storage

Question 18

What can microcompartments store?

Answer 18

1. Enzymes
2. Pigments for photosynthesis
3. Gas
4. Magnetite

Question 19

What pigments are used for photosynthesis?

Answer 19

phycobilisomes and chlorosomes

Question 20

What is magnetite? How is it stored?

Answer 20

iron compound stored in magnetosomes

Question 21

What are carboxysomes?

Answer 21

carbon fixation by RuBisCo

Question 22

What are endospores?

Answer 22

Metabolically inactive cells that are highly resistant to damage

Question 23

What causes formation of endospore? When does it germinate?

Answer 23

Forms during starvation, germinates in response to nutrient availability

Question 24

Can any bacteria form a spore?

Answer 24

No, only a few genera can

Question 25

Describe process to form a spore

Answer 25

Stage 0: normal growth
Stage 1: bacterial division (duplicate DNA)
Stage 2: Asymmetric septation (split the cell)
Stage 3: Engulfment (larger cell surrounds spore)
Stage 4: Cortex Synthesis (around spore)
Stage 5: Coat Synthesis (around spore)
Stage 6: Lysis of mother cell (larger cell lyse, leaving spore)
Stage 7: Free spore

Question 26

Describe the core of an endospore

Answer 26

DNA is tightly compacted around SASP which makes it UV resistant.
DIpicolinic acid draws water away making it heat resistant

Question 27

Describe the cortex of an endospore?

Answer 27

made up of special peptidoglycan which are loose and expansible