Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
Why is the Electron Transport Chain (ETC) located in the cristae of the mitochondria?
- correct answer Part of cellular respiration to create ATP. The cristae increases the
surface area of the inner membrane which allows faster production of ATP since
there's more places to do the process
What is the functional significance of the folds in the inner mitochondrial membrane
for the ETC? - correct answer The inner folds create the inter-membrane space that is
between them. The folds let more ETC enzymes and ATP synthase to be packed into
the mitochondrion.
What species gives up electrons in redox reactions and potentials? - correct answer
The species that is the getting oxidized.
What species takes on electrons in redox reactions and potentials? - correct answer
The species that is getting reduced.
How do you determine redox potential by combining half-reactions? - correct answer
1: Divide the equation into half-reactions
2: Balance each half-reaction for mass and charge
3: Equalize the # of electrons transferred
4:Add the half-reactions together
, Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
If Tin (II) chloride solution is mixed with an acidic potassium permanganate solution,
predict the redox reaction. - correct answer Tin (II) chloride solution = Sn2+, H2O,
and Cl-
Acidic potassium permanganate = K+, H2O, MnO4-
- Add it all into the same beaker
-Find what the strongest oxidizing and reducing agents
- Add the 2 half reactions together to find the product
How do you convert redox potential into free energy change? - correct answer Delta
G = -RT ln K
The Electron Transport Chain (ETC) full redox reaction catalyzed: reducing/oxidizing
species - correct answer Substrate: H2 (reduced) goes to the substrate (oxidized)
The acceptor: NAD + or FAD goes to H2 (NADH or FADH2)
Reduced e- carrier goes through oxidized e- carrier and thru and thru then to 2H +
1/2 O2 goes to H2O
How many protons are pumped by complex 1 in the ETC? - correct answer Pumps 4
protons
, Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
How many protons are pumped by complex 2 in the ETC? - correct answer Does not
pump protons directly, does send out 2 protons to the next complex in the form of
reduced ubiquinol
Ubiquinol - correct answer Also known as coenzyme Q, is a lipid with a quinone ring
structure at the top
- can be reduced with 2 electrons, then travels to complex III next
How many protons are pumped by complex 3 in the ETC? - correct answer Transfers 4
protons across the membrane per pair of electrons
How many protons are pumped by complex 4 in the ETC? - correct answer 4 protons:
2 protons per pair of electrons
ETC Complex I - correct answer NADH - Q (ubiquinol)
oxidorecductase
electrons from NADH
Mechanical/Conformational change
Oxidoreductase - correct answer - large, multi-subunit protein complex
- Accepts e- from NADH and passes them to FMN ( flavin mononucleotide like FAD)
, Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
- passes e- thru Fe/S clusters to ubiquinone 1 at a time
- uses this electrical work to pump 4 H+ ions out of the matrix into the
intermembrane space
Complex I net reaction: - correct answer NADH + 5H+ N + Q -> NAD+ + QH2 + 4H+
P
Protons are transferred thru proton "wires" - series of AA that undergo protonation
and deprotonation
ETC Complex III - correct answer Q-Cytochrome C oxitoreductase
- electrons to Cytochrome from QH2
QH2 oxidation gives 2 protons per QH2 consumed in the P-side ubiquinone binding
site, giving 2H+ p per step of the Q cycle
- The 1 electron reduced semi ubiquinone radical in the N-side ubiquinone binding
site consuming 2 protons from the N-side upon becoming fully reduced to ubiquinol
(QH2) resulting in net flow of protons to P-side
ETC Complex II - correct answer Succinate-Q dehydrogenase
- e- from FADH2
Succinate Dehydrogenase - correct answer Oxidizes succinate to fumarate
- 2 electrons are passed to FAD, forming FADH2
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
Why is the Electron Transport Chain (ETC) located in the cristae of the mitochondria?
- correct answer Part of cellular respiration to create ATP. The cristae increases the
surface area of the inner membrane which allows faster production of ATP since
there's more places to do the process
What is the functional significance of the folds in the inner mitochondrial membrane
for the ETC? - correct answer The inner folds create the inter-membrane space that is
between them. The folds let more ETC enzymes and ATP synthase to be packed into
the mitochondrion.
What species gives up electrons in redox reactions and potentials? - correct answer
The species that is the getting oxidized.
What species takes on electrons in redox reactions and potentials? - correct answer
The species that is getting reduced.
How do you determine redox potential by combining half-reactions? - correct answer
1: Divide the equation into half-reactions
2: Balance each half-reaction for mass and charge
3: Equalize the # of electrons transferred
4:Add the half-reactions together
, Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
If Tin (II) chloride solution is mixed with an acidic potassium permanganate solution,
predict the redox reaction. - correct answer Tin (II) chloride solution = Sn2+, H2O,
and Cl-
Acidic potassium permanganate = K+, H2O, MnO4-
- Add it all into the same beaker
-Find what the strongest oxidizing and reducing agents
- Add the 2 half reactions together to find the product
How do you convert redox potential into free energy change? - correct answer Delta
G = -RT ln K
The Electron Transport Chain (ETC) full redox reaction catalyzed: reducing/oxidizing
species - correct answer Substrate: H2 (reduced) goes to the substrate (oxidized)
The acceptor: NAD + or FAD goes to H2 (NADH or FADH2)
Reduced e- carrier goes through oxidized e- carrier and thru and thru then to 2H +
1/2 O2 goes to H2O
How many protons are pumped by complex 1 in the ETC? - correct answer Pumps 4
protons
, Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
How many protons are pumped by complex 2 in the ETC? - correct answer Does not
pump protons directly, does send out 2 protons to the next complex in the form of
reduced ubiquinol
Ubiquinol - correct answer Also known as coenzyme Q, is a lipid with a quinone ring
structure at the top
- can be reduced with 2 electrons, then travels to complex III next
How many protons are pumped by complex 3 in the ETC? - correct answer Transfers 4
protons across the membrane per pair of electrons
How many protons are pumped by complex 4 in the ETC? - correct answer 4 protons:
2 protons per pair of electrons
ETC Complex I - correct answer NADH - Q (ubiquinol)
oxidorecductase
electrons from NADH
Mechanical/Conformational change
Oxidoreductase - correct answer - large, multi-subunit protein complex
- Accepts e- from NADH and passes them to FMN ( flavin mononucleotide like FAD)
, Chem 153A Final Study Guide {Latest
Updated 2026/2027} Questions and
Answers (Graded A+) - Chamberlain
- passes e- thru Fe/S clusters to ubiquinone 1 at a time
- uses this electrical work to pump 4 H+ ions out of the matrix into the
intermembrane space
Complex I net reaction: - correct answer NADH + 5H+ N + Q -> NAD+ + QH2 + 4H+
P
Protons are transferred thru proton "wires" - series of AA that undergo protonation
and deprotonation
ETC Complex III - correct answer Q-Cytochrome C oxitoreductase
- electrons to Cytochrome from QH2
QH2 oxidation gives 2 protons per QH2 consumed in the P-side ubiquinone binding
site, giving 2H+ p per step of the Q cycle
- The 1 electron reduced semi ubiquinone radical in the N-side ubiquinone binding
site consuming 2 protons from the N-side upon becoming fully reduced to ubiquinol
(QH2) resulting in net flow of protons to P-side
ETC Complex II - correct answer Succinate-Q dehydrogenase
- e- from FADH2
Succinate Dehydrogenase - correct answer Oxidizes succinate to fumarate
- 2 electrons are passed to FAD, forming FADH2
