CH 22 Flashcards

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1
Q

3 major cell types of prokaryotes

A

Rods (bacillus), sphere (coccus), spiral (spirilla or spirochetes)

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2
Q

Almost all prokaryotes have a

A

cell wall

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3
Q

Function of cell wall, what is it made of

A
  1. Lies outside the plasma membrane
  2. Protects and prevents cell lysis
  3. Bacteria’s cell wall is made of peptidoglycan (PG)
  4. Archaea’s cell wall is made with other structural polysaccharides
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4
Q

what do gram stains do??

A

Gram stains help determine the cell wall type.
- A positive gram stain is purple. Shows bacteria with thick peptidoglycan layer
- A negative gram stain is pink. thin PG layer PLUS outer lipid bilayer membrane (has 2 phospholipid bilayers), outer lipopolysaccharide (LPS) layer that is toxic and resists drugs & immune system

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5
Q

True of False: many prokaryotes have a capsule or slime layer

A

True

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6
Q

4 functions of capsule/slime layer

A
  1. sticky carbs and proteins secreted outside cell wall
  2. adheres (glues) cells together or to surface (throat, rock, etc)
  3. resists attack from immune system (divide and grow before being discovered)
  4. holds in moisture (self preservation)
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7
Q

Some proteins have a hairlike protein ______.

A

fimbriae. Helps cells stick to surfaces and each other. Help bacteria colonize.

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8
Q

Sex pilus (pili=plural)

A

pulls 2 bacteria cells together for DNA transfer (conjugation), forms mating bridge. NOT SEXUAL REPRODUCTION, can exchange beneficial traits

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9
Q

taxis meaning. what are the 3 types

A

movement directed toward or away from a positive or negative stimulus
chemotaxis, phototaxis, geotaxis (magneto taxis)

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10
Q

how do prokaryotes move?

A

rotating flagellum protein fibers, not homologous to eukaryote flagellas

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11
Q

what do spirochetes have?

A

internal flagella

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12
Q

slime gliding

A

less understood, slime ejected through pours

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13
Q

where is the DNA located?

A

nucleoid (organized region of DNA and proteins)

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14
Q

what type of ribosomes? microtubules yes or no?

A

free ribosomes. no mictrotubules

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15
Q

in-folded plasma membranes

A

folds in the membrane that increase membrane surface area, enhance cell’s efficiency. only some have it. this is for aerobic cellular respiration or for O2 producing photosynthesis. BACTERIA THAT HAVE THIS LOOK SIMILAR TO MITOCHONDRIA AND CHLOROPLASTS

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16
Q

How many chromosomes in prokaryotes? what type of DNA

A

one chromosome, circular DNA with binding proteins. no histones, archaeans have histones, which ties them closer to eukaryotes. genes are much closer together

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17
Q

many have plasmids.

A

plasmids are the tiny DNA circular rings with few genes IN ADDITION TO THE MAIN BACTERIAL DNA. they usually carrynextra beneficial traits. plasmids can replicate independently of the main bacterial DNA. add diversity. random number plasmids per daughter cell

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18
Q

Binary fission

A

simple, asexual reproduction, cell divides into two genetically identical cells EXCEPT FOR PLASMIDS. short generation time

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19
Q

some bacteria can form resting spores

A

during environmental stress, bacteria can transform into endo/resting spore, where they can remain dormant and survive harsh conditions. some are pathogens, very resilient

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20
Q

akinetes

A

resting spore for when pond dries up rehydrates cyanobacteria. specifically cyanobacteria

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21
Q

importance of DNA mutations

A

prokaryotes have a low rate of point mutations. however because they have such a rapid generation time and rate of cell division, there are a lot of mutations. so it offsets it.

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22
Q

one mutation can change

A

phenotypes. they only have 1 chromosome, genes are more directly correlated to phenotype. all mutations (except lethal ones) are passed on in clones (from binary fissions)

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23
Q

Griffith’s experiment

A

Recombination by transformation. used mice. living S cells, mouse dies. Living R cells, mouse lives. Heat killed S cells, mouse lives. Heat killed S cells + living R cells = mouse dead. dead S cells lyse, releasing DNA. R cells pick up DNA and incorporate into genome.

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24
Q

horizontal gene transfer

A

DNA fragments from donor cells are absorbed directly by recipient. Homologous DNA with new alleles exchanges with DNA in chromosomes (recombination). Donor’s DNA combines with recipient DNA.

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25
Q

Recombination by transduction

A

DNA is carried by bacteriophage virus (virus that only infects bacteria). Phages inject viral DNA into bacteria. Uses host/cell resources to make more phages.

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26
Q

Transduction mistake

A

a phage capsule will accidentally trap bacterial DNA instead of viral DNA (whoops!) new alleles inserted into recipient cell (recombination). cross over incorporates new DNA alleles into chromosome. RECOMBINANT CELL IS DIFFERENT FROM BOTH DONOR AND RECIPIENT CELL!

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27
Q

Recombination by conjugation

A

requires F factor in donor. F factor builds sex pilus. it’s located on the F-plasmid or in chromosome. during conjugation, it transfers a strand of the f plasmid to the donor.

28
Q

HFR (high frequency recombination) cell conjugation

A

HFR donor’s F factor is part of chromosome. The Hfr donor transfers part of chromosome and F factor to F- recipient, allowing new alleles to be inserted into recipient’s chromosome. However, it did not acquire the FULL F factor, so it cannot become F+ and can’t donate an F factor to anyone.

29
Q

Photoautotroph energy source, carbon source

A

Light, Co2, HCO3. pokaryotes

30
Q

Chemoautotroph

A

Energy source: Inorganic chemicals (NH3),
Carbon source: CO2, prokaryotes only

31
Q

Photoheterotroph

A

Energy source: Light
Carbon source: organic compounds. aquatic prokaryotes

32
Q

Chemoheterotroph

A

Energy source: organic compounds, carbon source ogrganic compounds.

33
Q

Food Webs

A

Autotrophs are primary producers.

34
Q

Carbon fixation

A

Turning atmospheric oxygen into usable forms (organic molecules) happens during photosynthesis. important for aquatic food webs. photo and chemoautotrophs can do this

35
Q

Photic zone

A

as far as light can reach in the ocean.

36
Q

how do organisms obtain energy in the aphotic zone?

A

inorganic compounds (CHEMOAUTOTROPHS) Barophilic.

37
Q

what is the source of carbon in heterotrophs?

A

other organisms

38
Q

what are the most important decomposers on earth?

A

chemoheterotrophic bacteria. secrete enzymes that hydrolyze (break down) dead material. absorptive feeding: enzymes break down food into monomers, which then absorb into chemoheterotroph via diffusion/active transport. releases CO2, N, P, K,

39
Q

Obligate anaerobes

A

oxygen is toxic to them. ex. tetanus bacteria. the first cells were probably like this as there was little oxygen in the atmosphere.

40
Q

facultative anaerobes vs. obligate aerobes

A

can be aerobic and anaerobic. requires O2 .

41
Q

which organism is responsible for the oxygen revolution?

A

cyanobacteria photosynthesis

42
Q

what form of nitrogen is usable to most life?

A

NH4 (ammonium) or organic N compounds

43
Q

Nitrogen fixation

A

converts N2 from atmosphere to NH4 ammonium. cyanobacteria can do this at the HETEROCYST or symbiotic in plant roots

44
Q

metabolic cooperation

A

prokaryotes often grow better together (cyanobacteria in filaments w/ heterocysts) (biofilms on teeth are complex community of organisms)

45
Q

symbiosis vs. free living

A

two species living in close relationship vs. independently live

46
Q

commensalism

A

one species benefits without any impact on other species (bacteria on our skin)

47
Q

where are mutualistic bacteria mostyl found?

A

in the digestive tract. help ward off pathogenic bacteria, produce vitamins, activate immune system

48
Q

2 types of pathogenic bacteria

A

endotoxic vs. exotoxic.
Exotoxic: bacteria actively secrete toxins and attack cell signal receptors.
Endotoxic: cell wall components are released when the bacteria die, causing a general inflammatory response. the outer membrane toxic of gram-negative bacteria

49
Q

true or false: antibiotics kill bacterial and eukaryotic cells

A

flase. they only kill bacterial cells by targeting the production of peptidoglycan.

50
Q

bioremediation

A

using living organisms like bacteria, fungi, and plants to break down pollutants and help the environment.

51
Q

branched hydrocarbons are unique to

A

archaeans. helps them thrive in extreme conditions and stabilizes them.

52
Q

which domains have a nuclear envelope

A

Eukaryotes

53
Q

which domains have membrane enclosed organelles

A

eukarya

54
Q

which domains have peptidoglycan in cell walls?

A

bacteria

55
Q

which domains have circular chromosomes?

A

archaea and bacteria

56
Q

which domains have histones

A

some archaea and all eukaryotes

57
Q

5 kingdoms of domain bacteria

A

proteobacteira, chlaymdias, spirochetes, cyanobacteria, gram positive bacteria

58
Q

Kingdom proteobacteria, examples

A

gram-negative; diverse metabolisms/nutrition
ex: N cycle bacteria, gastrointestinal; pathogens that cause food poisoning, E. coli, salmonella, vibrio choleri

59
Q

Chlamydias , examples

A

Gram-negative ; all are endoparasites (lives inside host)
ex. chlamydia STD

60
Q

Spriochetes, examples

A

spiral shape, many are free living but can cause disease
ex. syphilis (STD), lyme disease

61
Q

Cyanobacteria

A

Plant like, generate O2 by photosynthesis, some are N-fixers (using heterocysts), colonies of cyanbacteria (blooms)can produce harmful substances

62
Q

kingdom gram-positive bacteria, examples

A

includes many decomposers in soils, some sources of antibiotics, many pathogens
ex. anthrax, tetanus, staph, MRSA infection, strep throat, TB (tuberculosis), leprosy

63
Q

Domain Archaea

A

extremophiles and methanogens (produce methane (CH4) through anaerobic respiration . can be normal. do not cause human disease.

64
Q

halophiles

A

domain arcahea: love salty water. thermophiles lov

65
Q

thermophiles

A

love boiling point temperature, domain archaea