Exam 2: Electron Transport Chain Flashcards
Which stage of respiration is the ETC?
Stage 4
What is the final electron acceptor of the ETC?
Oxygen
Which molecules bring electrons to complexes?
NADH and FADH2
Which enzyme do protons move through?
ATP Synthase
Which type of phosphorylation is used in the ETC?
Oxidative phosphorylation
How many complexes are the ETC proteins organized into?
4 (I-IV)
Which complexes pump protons?
I, III, and IV
Where do the complexes pump protons to?
From the mitochondrial matrix into the intermembrane space
What transfers electrons between complexes?
Q and cytochrome c
Which complex does NADH bring electrons to?
Complex I
Which complex does FADH2 bring electrons to?
Complex II
What is Q?
The electron carrier, ubiquinone
Q transfers electrons (and protons) between which complexes?
Complex I to Complex II, and Complex II to Complex III
Cytochrome c transfers electrons between which complexes?
Complex III to Complex IV
What is chemiosmosis?
Movement of hydrogen ions into the mitochondria
=> A process in which the proton-motive force from the ETC electrochemical gradient is used to make ATP
Why is there a proton gradient?
The complexes pump protons out of the mitochondria, which means there are more protons on the outside than on the inside
What are the 2 units of ATP synthase?
F0 and F1
Which unit do protons enter ATP synthase through?
F0
Once protons enter the F0 unit, what spins?
the rotor
The rotor spins what?
the F1 unit
Where does ATP synthesis occur?
on the protein subunits of the F1 unit
How much ATP is made from the ETC?
25
What polyatomic ion does E coli use as an electron acceptor?
nitrate (NO3-)
Oxygen, the final electron acceptor, forms what after it receives the electrons?
Water
When does anaerobic respiration occur?
When there is no oxygen
What are two ways to produce ATP when there is no oxygen?
- Use something other than oxygen as the final electron acceptor
- Use only the ATP made from glycolysis (only 2 net atp)
What happens in lactic acid fermentation?
Pyruvate accepts electrons from NADH, forming NAD+ and lactate
Which types of organism undergo alcohol fermentation?
Yeast and bacteria
What happens in alcohol fermentation?
Pyruvate is converted to acetaldehyde and CO2, acetaldehyde accepts electrons from NADH, ethanol and NAD+ are produced
