L14: Chemiosmotic Theory

Question 1

Who tf is Mitchel

Answer 1

• chemioosmotic theory, oxxidative phylprylation and photophosphoryaltion t

Question 2

Explore TEA vs Depth

Answer 2

• different TEAs are available in diff nich related to depth in envir
  *reduction potential of TEA decrease with depth => less energy the more you go down

Question 3

What do chemotrophs do

Answer 3

*transfer e- brained from energy source to most oxidisng TEA allowing they to generate energy by respiration

Question 4

Discuss TEA in water coloumn

Answer 4

• the stronger the oxidation potenital of compound the easier to reduce the better TEA
  *better TEA means we can pump more H+ per electron because they are falling further

Question 5

Best/ Worse TEAs, best metallic ones?

Answer 5

*O2 is best, accept easily
*CO2 is worse, not easily reduced

Question 6

Winogradsky TEAs

Answer 6

*has aerobes, microaerophieles at specific intervals based on TEA
*some use one, some use many

Question 7

Basics of Aerbic respiration

Answer 7

*chemotrophic metabolism using O2 as TEA
*NAD+ drives oxidation of e donar
*NADH, NADPH, FADH generated by metabolism due to oxidation of the energy soruce (reducing power)
*this is passed to ETC then to TEA from here two things can happen
- O2 => H2O via terminal oxidase or e- used for biosynthetic reactions
*this flow generated proton/pH gradient which fuels process

Question 8

Aeorbic respirartion yeild,, caviet

Answer 8

3 ATP per NADH
2 ATP per FADH

the ATP per reducing power is not the same as in mitochondira, and can also vary amongst bac species

• composition of etc also changes depending on difference conditions and this effect efficacy and yeld

Question 9

Where does CO2 come from

Answer 9

metabolic pathways like the TCA cycle

Question 10

What are microareophiles

Answer 10

*obligate aeorobes that requrie low O2
*have a high affinity for O2 terminal oxidase and explore nutrient/O2 gradeints
*some can fix N2

Question 11

What are facultative anaeobe example

Answer 11

*E.coli, can switch between arobic respitation or fermentation depending on O2

fermentation of glucose can produce lactate or ethanol + CO2

Question 12

What is fermentation (energy, C, Edonor, EA, water)

Answer 12

• in chemotrophs that used organic compounds as e-donors (energy source) and e-acceptros
  *C source: organic compounds
  *Energy: by oxidation of organic productions

*NAD+ drives oxidation of donor
*NAD+ is regnerated by transfer of e from NADH to organic compounds

waste products: reduced organic compounds like organic acids, alcholos and H2 gas

Question 13

Fermentation ATP, proton gradeint and heat

Answer 13

ATP: produced by substrate level phosphorylation which does
PEP => pyruvate + ATP via pyruvate kinase

Proton gradient: maintained by hydrolysis by H+-ATaseP but some fermenters do not have this enzyme

Heat: can be generated if protons leak back intro the cell resulting in a futile cycle, this competes with other organisms for glucose so some organisms allow when glucose is high

Question 14

What is more effiect fermentation or respiration

Answer 14

F is less effiecent for ATP yeild, cells use much more glucose (energy source) to produce the same amount of ATP

Question 15

What is aneorbic respiration, TEA, e- behaviour, cycles, similar to?

Answer 15

*alternate TEA with ETC
*e-s dont drop as far (to reach O) so there are fewer H+s: low energy yield

example: dissimilaory sulfate or nitrate reduction (denitrification)

NAD+ drives oxidation of e donor

similar to methanogensis where e- are transferred to CO2 yielding CH4 as waste

Question 16

Can anaerobic respiration still work TCA cycle

Answer 16

ETC can still oxidise NADH to NAH so yes

Question 17

Descibe TEA of anaro respiration + key go through example

Answer 17

can be inorganic, metalic or organic

fumarate => succinate via fumarate reductase
- membrane bound enzyme part of ETC, inertnal resource so not related to depth