Exam 1- ch 27

Question 1

what are the three domains of life?

Answer 1

bacteria, archaea, eukarya

Question 2

which domain of life contain prokaryotes? eukaryotes?

Answer 2

prokaryotes= bacteria and archaea
eukaryotes= plants, fungi, animals

Question 3

when did prokaryotes evolve

Answer 3

~3.5 billion years ago

Question 4

prokaryotic cell wall functions

Answer 4

cell shape; cell lysis in hypotonic solution

Question 5

prokaryotic bacteriacell wall content

Answer 5

peptidoglycan (aka MUREIN; sugars cross linked with peptidoglycan)

Question 6

archaeal cell wall content

Answer 6

pseudomurein

Question 7

eukaryotic cell wall content

Answer 7

cellulose (plants) or chitin (fungi) *animals obvi dont have cell wall

Question 8

explain gram positive cell wall

Answer 8

PURPLE because it traps the crystal violet; thick cell wall

Question 9

explain gram negative cell wall

Answer 9

RED because the alcohol rinses away the crystal violet; thin cell wall; double plasma membrane; has LPS on outermembrane= source of endosporins; TOXIC

Question 10

how does penicillin inhibit prokaryotic growth?

Answer 10

prevents transformation of the peptidoglycan wall; aka prevents new cell wall from forming

Question 11

what is a capsule made of and what is it’s function (2)

Answer 11

made of polysaccharides (aka protein); it makes the prokaryote adhere to substrate/ other ind to form a colony; provides protection from phagocytosis from host’s immune system

Question 12

function of an endospore

Answer 12

dormant state; protects bacterium in harsh conditions (like lacking essential nutrient, withstands boiling water)

Question 13

what are fimbriae and pilus

Answer 13

hair like appendages; both contribute to attachment; pilus also conjugates!

Question 14

3 ways prokaryotes are able to move via taxis; what is taxis?

Answer 14

taxis= ability to move in response to stimulus
chemotaxis, phototaxis, aerotaxis

Question 15

3 way prokaryotes can move themselves?

Answer 15

flagella (some lack), cork screw motion, production of slime layer

Question 16

where is the respiratory membrane? what does it do

Answer 16

cristae of the mitochondria; performs aerobic respiration/ ETC for ATP

Question 17

where is the thylakoid membrane? what is their purpose?

Answer 17

in chloroplasts; provides pigments for photosynthesis

Question 18

prokaryotic vs eukaryotic ribosome

Answer 18

prokaryotic= 50S and 30S subunits= 70S
eukaryotic= 60 S and 40S subunits= 80S

Question 19

where is the chromosome location in prokaryotes

Answer 19

nucleoid

Question 20

plasmid is __,__ DNA that replicate ___ of the chromosome

Answer 20

small, circular
independently

Question 21

prokaryotes reproduce quickly via __ __ (asexually); divide every _-__ hours some divide every __ minutes

Answer 21

binary fission
1-3 hours; 20 minutes

Question 22

reproduction via binary fission results in daughter cells being genetically ____ with __ mutation rates

Answer 22

identical
low

Question 23

rapid reproduction in prokaryotes allow for ??

Answer 23

mutations to accumulate rapidly in a population + short generation time means prokaryotes evolve quickly

Question 24

describe transformation (horizontal gene transfer)

Answer 24

donor cell releases DNA and the recipient cell takes it up from its enviroment

Question 25

describe transduction (horizontal gene transfer)

Answer 25

phage infected donor cell releases phage into recipient cell

Question 26

describe conjugation (horizontal gene transfer)

Answer 26

f plasmid from donor cell travels to recipient cell via pilus

Question 27

what happens with nitrogen fixation

Answer 27

prokaryotes convert atmospheric nitrogen (N2) to ammonia (NH3)

Question 28

archaea are either ___ or ___

Answer 28

extremophiles or methanogens

Question 29

archaea are more similar to ___ and are or arent pathogenic?

Answer 29

eukaryotes nonpathogenic

Question 30

methanogens (archaea) live in __ and __ to use ___ to OXIDIZE ___, which produces __ as a waste product

Answer 30

swamps and marches CO2 to oxidize H2 --> methane (C4)

Question 31

methanogens are strict __ and are poisoned by __

Answer 31

anaerobes, O2

Question 32

archaea represent __% of oceanic prokaryotes & generate ~__% of methane

Answer 32

20% 85%

Question 33

Bacteria *answer present or nonpresent* -nuclear envelope -membrane organelles -peptidoglycan cell wall -circular chromosome

Answer 33

absent absent present present

Question 34

Eukaryotes *answer present or nonpresent* -nuclear envelope -membrane organelles -peptidoglycan cell wall -circular chromosome

Answer 34

present present absent absent (linear)

Question 35

Archaea *answer present or nonpresent* -nuclear envelope -membrane organelles -peptidoglycan cell wall -circular chromosome

Answer 35

absent absent absent present!

Question 36

what kind of prokaryotes function as decomposers?

Answer 36

chemoheterotrophic

Question 37

what kind of bacteria break down food that is undigested by our intestines? what can they produce?

Answer 37

mutualistic bacteria! vitamins like K, B2, B12

Question 38

mutualistic bacteria can also protect us by preventing the growth of __ __ or __

Answer 38

pathogenic bacteria fungi

Question 39

what bacteria cause about half of all human disease?

Answer 39

pathogenic bacteria

Question 40

what pathogenic bacteria lives in throats of healthy people, but cause pneumonia when host defense is down

Answer 40

streptococcus pneumoniae

Question 41

what pathogenic bacteria is found in the skin, but can cause skin infections if they get inside a cut

Answer 41

staphylococcus aureus ; *methicillin-resistant s. aureus (MRSA) is a prob in hospitals

Question 42

what pathogenic bacteria causes diarrhea and colitis

Answer 42

C. difficile

Question 43

what is a vector

Answer 43

species (like arthropods/ insects) that transmit bacterial diseases; ex: lyme disease

Question 44

how do pathogenic prokaryotes typically cause disease

Answer 44

by producing exotoxins or endotoxins

Question 45

what is unique about exotoxins? what kind of cell wall are they present in?

Answer 45

exotoxins are secreted and causes disease even if prokaryotes that produce them are not present; both gram + and -

Question 46

what are two examples of exotoxins? the one that causes diarrhea (poor sanitation) and the one that causes food poisoning (improper canning)

Answer 46

V. cholerae C. botulinum (1 g can kill 1x106 people)

Question 47

what is unique about endotoxins? what kind of cell wall are they present in ?

Answer 47

released only when bacteria die and their cell wall breaks down; LPS components of the outer membrane of gram NEGATIVE cell walls

Question 48

example of endotoxin?

Answer 48

salmonella typhi (typhoid fever)