Prokaryotes

Question 1

what structural components do prokaryotes have?

Answer 1

single celled, contains ribosomes, dna, and has a cell membrane

Question 2

what is domain archaea?

Answer 2

the oldest taxonomic domain, contains organisms that live in extreme environments

Question 3

what are methanogens?

Answer 3

prokaryotes that produce methane as a by product, live in anaerobic muds, intestines, and are heterotrophs

Question 4

what are halophiles?

Answer 4

salt loving prokaryotes, use photosynthetic pigments to capture light energy

Question 5

what is domain bacteria?

Answer 5

-“true” bacteria, has aerobic and anaerobic forms
-photosynthetic, fermentation, and parasites

Question 6

what are the 7 key features of domain bacteria?

Answer 6

1. morphology
2. cell surface & cell wall
3. internal organelles
4. genome
5. reproduction
6. nutrition
7. oxygen requirements

Question 7

what is the morphology of domain bacteria?

Answer 7

-single celled
-shape: rods [bacilli], spherical [cocci], spiral [spirilla]
in pairs = diplo_
in lines = strepto_
in clusters = staphylo_

Question 8

what are the cell membrane contents of domain bacteria?

Answer 8

-contains peptidoglycan - sugars linked together with amino acids
-cell walls may be covered by a capsule: a sticky layer of polysaccharides or proteins

Question 9

how does peptidoglycan concentration influence bacterial type?

Answer 9

lots of peptido in cell wall = gram +, look purple
not lots of peptido in cell wall = gram -, look pink, also contain an outer membrane on top of the plasma membrane and are more pathogenic

Question 10

what are bacterial fimbriae ?

Answer 10

“spikes” that allow bacteria to stick to their substrate or other members of a colony
can also attach to host membranes

Question 11

what are bacterial pili?

Answer 11

appendages to pull cells together or transfer DNA

Question 12

what do bacterial endospores do?

Answer 12

allows the cell to become highly dormant and “hibernate” to let it remain in harsh conditions for very long periods of time

Question 13

how do bacterial internal organelles work?

Answer 13

-the bacterial plasma membrane can infold on itself to achieve specific functions

Question 14

what are the contents of a bacterial genome?

Answer 14

• a single circular, ds chromosome
  -very little protein with DNA, may see plasmids

Question 15

how do bacteria reproduce and how often can they?

Answer 15

-bacteria reproduce through binary fission
-can do so every 1-3 hours

Question 16

what are the three types of bacterial reproduction?

Answer 16

1. transformation
2. transduction
3. conjugation

Question 17

what is bacterial transformation?

Answer 17

-donor cell releases DNA into environment
-proteins on recipient surface membrane bind to the DNA molecules and let them into cell
-SS donor DNA is incorporated into host chromosome

Question 18

what is bacterial transduction?

Answer 18

-bacteriophages may sometimes accidentally [finish latyer]

Question 19

what is bacterial conjugation for F+ / F- cells?

Answer 19

-F+ cell forms a mating bridge with F- cell and transfers its F+ plasmid into the F- cell
-this creates two F+ bacterial cells

Question 20

what is bacterial conjugation for Hfr/F- cells?

Answer 20

-Hfr cell forms a mating bridge and incorporates F factor DNA from its circular chromosome into the F- cell
-this creates a recombinant F- bacterium

Question 21

what do the photo, auto, hetero, and chemo prefixes mean for bacterial nutrition?

Answer 21

photo = obtains energy from light
chemo = obtains energy from chemicals
auto = uses CO2 as energy source from self
hetero = needs organic nutrients as a carbon source

Question 22

what are the 3 types of oxygen requirements for bacteria?

Answer 22

obligate aerobes = need oxygen to survive
facultative aerobes = fine with or without oxygen but prefer without
obligate anaerobes = oxygen is poisonous

Question 23

what are 4 ways bacteria contribute to the environment?

Answer 23

1. chemical recycling of elements between living/nonliving components of environment
2. act as decomposers
3. nitrogen fixing = add nitrogen to environment
4. can form symbiosis with other organisms for mutual benefit

Question 24

what are bacterial exotoxins?

Answer 24

-secretions from a bacteria that can cause disease

Question 25

what are bacterial endotoxins?

Answer 25

toxins released from the cell wall of a bacteria when the bacteria dies