Bacteria

Question 1

What are some common morphology of bacteria?

Answer 1

coccus - spherical
bacillus - rod
spirillum - spiral
pleiomorphic - varied shapes

Question 2

Eukaryotes are __________ than most Prokarya

Answer 2

larger

Question 3

What are the advantages to a high surface-volume ratio?

Answer 3

• greater rate of nutrient/waste exchange
• higher metabolism
• faster growth
• faster evolution

Question 4

Where are very small cells common?

Answer 4

Marine environments

Question 5

What is the largest part of bacterial cells?

Answer 5

the nucleoid region

Question 6

How does DNA compress within the nucleoid?

Answer 6

• cations to shield negative charges
• positively charges proteins
• supercoiling

Question 7

How does bacteria maintain its shape?

Answer 7

Bacterial cytoskeleton

Question 8

What is MreB?

Answer 8

a protein that is a homolog of actin

Question 9

What is FtsZ?

Answer 9

a protein that is a homolog of tubulin

Question 10

Define Cell Envelope

Answer 10

The layers that surround the cytoplasm of cells (membrane, wall, outer membrane)

Question 11

The cell membrane is a __________ barrier, Not a ____________ barrier

Answer 11

permeability, structural

Question 12

rigidity in cells can be caused by:
fluidity in cells can be caused by:

Answer 12

saturated fatty acid tails in the membrane.
unsaturated fatty acid tails in the membrane.

Question 13

How does h2o cross the membrane?

Answer 13

aquaporin protein channels (osmosis)

Question 14

What is facilitated diffusion?

Answer 14

• materials move through protein channels using concentration gradient
• does NOT use ATP

Question 15

What is co-transport?

Answer 15

Form of active transport (uses ATP)

Question 16

Define protein secretion

Answer 16

• shipping proteins outside the cell
• uses ATP energy

Question 17

How do nutrients get through Gram-positive bacterial cell walls?

Answer 17

Large pores in the matrix

Question 18

How do nutrients get through Gram-negative bacterial cell walls?

Answer 18

Porins and TonB proteins in outer membrane

Question 19

Name and describe the 4 main flagella arrangements

Answer 19

Monotrichous - one flagella at pole
Amphitrichous - a flagella at each pole
Lophotrichous - many flagella at pole
Peritrichous - many flagella all over cell body

Question 20

Flagella are composed of three basic pieces:

Answer 20

1. Filament of multiple flagellin proteins
2. Hook protein that connects filament to basal body
3. Basal body (disk-like structure that turns filament like a propellor)

Question 21

How do cells move their flagella?

Answer 21

Proton motive force (PMF)

Question 22

Define chemotaxis

Answer 22

Chemoreceptor proteins temporarily sense changes in attractants and repellants

Question 23

Describe methods of nonflagellar activity

Answer 23

Gliding motility - smooth sliding over surface (cyanobacteria)
Twitching motility - jerky movement using pili
Actin in host cells causing bacterial propulsion into adjacent cells

Question 24

What are adherence molecules?

Answer 24

pili, pilin protein fibers, other proteins that allow cells to stick to surfaces

Question 25

Define stalk

Answer 25

Extension of cell envelope that provides extra surface area for nutrient absorption (good for low-nutrient environments)

Question 26

What are capsules?

Answer 26

• Thick layer of polysaccharides that surround cells and provide protection, help bacteria form biofilm, and enhance survivability (found on many pathogens)
• Found in Gram-positive and Gram-negative cells

Question 27

What are S-layers?

Answer 27

• Array of interlocking proteins that most likely protect against predation or infection
• Found in Gram-positive, Gram-negative, and archaeal cells