Bacteria Flashcards

1
Q

What are some common morphology of bacteria?

A

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

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2
Q

Eukaryotes are __________ than most Prokarya

A

larger

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3
Q

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

A
  • greater rate of nutrient/waste exchange
  • higher metabolism
  • faster growth
  • faster evolution
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4
Q

Where are very small cells common?

A

Marine environments

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5
Q

What is the largest part of bacterial cells?

A

the nucleoid region

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6
Q

How does DNA compress within the nucleoid?

A
  • cations to shield negative charges
  • positively charges proteins
  • supercoiling
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7
Q

How does bacteria maintain its shape?

A

Bacterial cytoskeleton

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8
Q

What is MreB?

A

a protein that is a homolog of actin

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9
Q

What is FtsZ?

A

a protein that is a homolog of tubulin

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10
Q

Define Cell Envelope

A

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

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11
Q

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

A

permeability, structural

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12
Q

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

A

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

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13
Q

How does h2o cross the membrane?

A

aquaporin protein channels (osmosis)

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14
Q

What is facilitated diffusion?

A
  • materials move through protein channels using concentration gradient
  • does NOT use ATP
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15
Q

What is co-transport?

A

Form of active transport (uses ATP)

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16
Q

Define protein secretion

A
  • shipping proteins outside the cell
  • uses ATP energy
17
Q

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

A

Large pores in the matrix

18
Q

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

A

Porins and TonB proteins in outer membrane

19
Q

Name and describe the 4 main flagella arrangements

A

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

20
Q

Flagella are composed of three basic pieces:

A
  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)
21
Q

How do cells move their flagella?

A

Proton motive force (PMF)

22
Q

Define chemotaxis

A

Chemoreceptor proteins temporarily sense changes in attractants and repellants

23
Q

Describe methods of nonflagellar activity

A

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

24
Q

What are adherence molecules?

A

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

25
Q

Define stalk

A

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

26
Q

What are capsules?

A
  • 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
27
Q

What are S-layers?

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