Class 8

Where is the Electron Transport System

in the cytoplasmic membrane

why is the ETC in the cytoplasmic membrane

so the protons are separate from the electrons

what is the result of the ETC

pH gradient and electrochemical potential across membrane (PMF)

where is PMF stored

periplasm area

what prevents H+ from getting back into the cell

the selectively permeable plasma membrane

the PMV is a source of

energy

where is the concentration of protons (H+) high

extracellular fluid

what converts PMF → ATP

ATPase

what are the two components of the ATPase

F1 and F0

what does the PMF use to make ATP

ADP + Pi

How many H+ are needed per ATP

3-4 H+

How many ATP are needed per 2 electrons moving through the ETC

3 ATP

• extends into the cytoplasm

• large multiprotein extramembrane complex

• site for ATP synthesis or hydrolysis

• considered the ATP factory

F1

• embedded in plasma membrane 

• channel for H+

• flow of H+ causes rotational movement

• proton motor

F0

uses rotary motion to synthesize ATP

F1

uses PMF for rotary motion

F0

what does ATPase generate PMF for in fermenters

flagellar rotation

what is the total energy from 1 glucose for aerobic respiration

38 ATP

where do 34 of the ATP come from for aerobic respiration

from the NADH that feeds the ETC

what do the 38 ATP for aerobic respiration come from

glycolysis and citric acid cycle

how many ATP come from glycolysis for respiration, and how is it broken down

8

-2 from substrate level phosphorylation

-6 from oxidative phosphorylation

how many ATP come from the citric acid cycle for respiration, and how is it broken down

30

-2 from substrate level phosphorylation

-28 from oxidative phosphorylation

in what process is there no terminal electron acceptor to allow ETC

fermentation

what do the cells need to do to allow glycolysis to form ATP

recycle NADH back to NAD+

glycolysis and fermentation provide __________ than respiration

much less energy

since fermentation has no _______, we need _______ to convert to _________

ETC, NADH, NAD+

what does allowing additional ATP synthesis from substrate-level phosphorylation involve

coenzyme-a derivatives

why does bread have holes

releases CO2 gas

in aerobic respiration, what is the electron acceptor and what provides the electron

acceptor: O2

donor: NADH

what is the terminal electron acceptor in anaerobic respiration

something other than O2 (NO3-, Fe3+ etc..)

why is there less energy in anaerobic than aerobic

the E values on the redox tower, O2 is at the bottom so it is the best terminal electron acceptor for allowing most energy release, and anaerobic does not use O2D

what is similar about anaerobic and aerobic respiration

they both have ETC to create PMF

freshwater, marine sediments, and soil are examples of

anoxic environments

what are 4 examples of anaerobic respiration

1. Dissimilative nitrate reduction (denitrification)

2. sulfate reduction

3. methanogenesis (CO2 is acceptor)

4. proton reduction

what are the most common electron acceptors for anaerobic respiration

inorganic Nitrogen compounds

what is a bacteria that reduces NO3- to NO2-

E. coli

what is a bacteria that reduces NO3- to N2 (denitrification)

Pseudomonas stutzeri

what is denitrification

converting NO3- to N2

in denitrification, what is the electron donor

NADH

what are the electron acceptors in denitrification

the reduced N components

where are protons released, and why in denitrification

periplasm, to generate PMF

what does anaerobic respiration get help from to make ATP

ATPase in the periplasm

where are peripheral proteins located

on top of membrane

How many protons per NADH in aerobic respiration

8

how many protons per NADH in nitrate reduction

6

what does it mean when you have less protons pumped than if you have more

less means less PMF and less energy

why is energy higher from aerobic respiration than nitrate reduction

because O2 is lower on the redox tower than NO3- and aerobic respiration uses O2, therefore it generate more energy than NO3-