Exam 3 Quiz 3

Question 1

thermophiles

Answer 1

-soils in direct sunlight
-seen around hotsprings

Question 2

hyperthermophiles

Answer 2

-hot springs and steam vents
-more extreme hot ranges

Question 3

proteins/enzymes in thermophiles

Answer 3

-highly hydrophobic interior
-stabilizing solutes

Question 4

stabilizing solutes used in enzyme

Answer 4

• di-inositol phosphate
  -diglyceride phosphate

Question 5

membrane of thermophiles

Answer 5

-saturated, long chain fatty acid
-more hydrophobic environment
-higher melting point

Question 6

Archaea membrane in hyperthermophile environment have

Answer 6

biphatanol that gives a monolayer instead of bilayer

Question 7

internal pH

Answer 7

has to be between 5-9

Question 8

typical pH of neutrophiles on outside

Answer 8

7

Question 9

what is used to keep the pH at 7?

Answer 9

a buffer, typically sodium bicarbonate or potassium phosphate

Question 10

acidophiles

Answer 10

-more archaea seen here than bacteria
-seen when pH below 5.5
-[ ] of protons greater outside the cell

Question 11

how do acidophiles survive

Answer 11

-transport cations into cell to balance out (typically K+)
-proton transporters that protons in and back out
-highly impermeable membrane to deter protons from crossing

Question 12

Alkaliphiles

Answer 12

• [ ] of protons lower outside the cell
  -uses sodium mode of force, not proton mode of force
  -pH around 8 and higher

Question 13

what do most bacteria prefer?

Answer 13

isotonic (E. coli) or slightly hypotonic environments

Question 14

how do bacteria survive hypotonic conditions

Answer 14

mechanosensitive channels

Question 15

mechanosensitive channels

Answer 15

detect increased tension/pressure on membrane and will open channels to release excess solutes

Question 16

how do bacteria survive hypertonic environments

Answer 16

compatible solutes

Question 17

compatible solutes main idea*****

Answer 17

-draw in a solute or synthesize solute that allows you to even out
-make sure it doesn’t downplay a necessary enzymatic pathway
-CAN NOT inhibit cellular metabolism

Question 18

how are compatible solutes controlled?

Answer 18

genetically controlled

Question 19

genetically controlled

Answer 19

categorized by how much compatible solutes present

Question 20

haplophiles

Answer 20

grow optimally in the presence of NaCl

Question 21

mild haplophile

Answer 21

1-6% NaCl

Question 22

moderate haplophile

Answer 22

7-15% NaCl

Question 23

extreme haplophile

Answer 23

15-30% NaCl

Question 24

Halotolerant organisms

Answer 24

grow best in the absence of NaCl but can withstand a small concentration in the environment

Question 25

bacteria and archaea use what for their compatible solute

Answer 25

inorganic substance, typically KCl

Question 26

aerobe

Answer 26

-requires gaseous oxygen for metabolism
-e- acceptor
-21% oxygen concentration

Question 27

microaerophile

Answer 27

-cannot withstand atmospheric oxygen levels but requires a low level of oxygen
-found in deeper ocean and deep soil
-2-10% oxygen

Question 28

anaerobes

Answer 28

do not use gaseous oxygen in metabolism

Question 29

aerotolerant

Answer 29

does not use oxygen inmetabolism but can be in the presence of oxygen

Question 30

obligate/strict anaerobe

Answer 30

cannot be in the presence of oxygen or will die

Question 31

facultative anaerobes

Answer 31

-can use oxygen in respiration but can also live in its absence
-only will convert to a different source if there is no oxygen available
-can use anerobic respiration or fermentation as other option

Question 32

thioglycollate broth ingredients

Answer 32

-sodium thioglycollate that reduces O2 (not perfect system bc vented cap)
-redox indicator that tells you where O2 is in tube by turning pink
-small amount of agar to add viscosity

Question 33

aerobes in T broth

Answer 33

grow at top in the pink layer

Question 34

facultative anaerobes in T broth

Answer 34

prefer O at the top near pink but can grow throughout

Question 35

aerotolerant in T broth

Answer 35

all throughout broth without any bias

Question 36

anaerobes in T broth

Answer 36

only found at the bottom of the tube where O not present

Question 37

Microaerophile in T broth

Answer 37

not used/ not good because you will not form a good gradient bc of the 2-10% O requirement

Question 38

oxygen in cellular respiration

Answer 38

can be converted into toxic oxygen byproducts or reactive oxygen species

Question 39

reactive oxygen species

Answer 39

not good, highly reactive with proteins or anything thats around

Question 40

examples of toxic byproduct

Answer 40

-singlet oxygen
-superoxide anion
-hydrogen peroxide
-hydroxyl radical

Question 41

first byproducts made

Answer 41

superoxide anion and hydrogen peroxide , they need enzymes to prevent these from sticking in their cells

Question 42

enzymes that combat hydrogen peroxide

Answer 42

catalase and peroxidase

Question 43

enzyme that combats superoxide anion

Answer 43

superoxide dismutase

Question 44

how do superoxide anion and hydrogen peroxide form

Answer 44

in electron transport chain, flavoproteins, quinones, and Fe-S proteins allow for side reactions where they form

Question 45

aerotolerant prevention methods

Answer 45

use protein-free manganese complexes

Question 46

strict anaerobes

Answer 46

-see only superoxide reductase which is odd because anaerobes don’t need oxygen
-also no oxygen byproduct formed