EBIO 1210 EXAM 2 STUDY GUIDE WITH COMPLETE SOLUTIONS
Know where in the cell each stage takes place -- Answer ✔✔ -Glycolysis: Cytosol
-Pyruvate oxidation: Mitochondrial matrix
-Citric acid cycle: Mitochondrial matrix
-Oxidative phosphorylation: Inner mitochondrial membrane
Understand the fate of the carbons that enter the system as one 6-carbon glucose --
Answer ✔✔ Glucose → pyruvates → acetyl-CoA → CO2
-A 6-carbon glucose molecule is split into two 3-carbon molecules called pyruvates
-Pyruvate is needed in order to create acetyl CoA
-The 3-carbon pyruvate molecule made in glycolysis loses a carbon to produce a new, 2-
carbon molecule called acetyl CoA
-The carbon that is removed takes two oxygens from pyruvate with it, and exits the
body as carbon dioxide
-CO2 is the waste product that you release when you exhale
Identify the electron carriers (NADH and FADH2) and understand the general flow of
electrons through each stage -- Answer ✔✔ -Glycolysis: NADH is an output and goes
to the final stage
-Pyruvate oxidation: NADH is an output and goes to the final stage
-Citric acid cycle: NADH and FADH2 are outputs and go to the final stage
-Oxidative phosphorylation: NADH and FADH2 are inputs
Identify the final (terminal) electron acceptor of the mitochondrial electron transport
chain and understand its essential role in aerobic respiration -- Answer ✔✔ -Oxygen
-Without oxygen, ATP levels drop quickly, and we die
Understand how the electron transport chain creates a proton gradient -- Answer ✔✔ -
Proton pumping
-The proton gradient produced by proton pumping during the electron transport chain
is used to synthesize ATP
, Know how the proton gradient drives the synthesis of ATP via the protein ATP
synthase (the spinning turbine) -- Answer ✔✔ Protons flow down their concentration
gradient into the matrix through the membrane protein ATP synthase, causing it to spin
(like a water wheel) and catalyze conversion of ADP to ATP.
Understand the roles of active transport and passive transport (facilitated diffusion)
across the inner mitochondrial membrane during oxidative phosphorylation -- Answer
✔✔ -Active transport: movement of protons from the mitochondrial matrix to the
intermembrane space
-Passive transport: the movement of protons through the mitochondrial ATP synthase
occur
Relative amounts of ATP production in respiration -- Answer ✔✔ -Glycolysis = a little
ATP
-Pyruvate oxidation = no ATP
-Citric acid cycle = a little ATP
-Oxidative phosphorylation= lots of ATP; most ATP is made here
Explain how the uncoupling protein results in in the production of heat instead of ATP
in brown fat cells -- Answer ✔✔ -It provides a channel across the membrane through
which protons (H+) flow back into the matrix
-Protons don't cross the membrane via ATP synthase → almost no ATP is made
-Energy is released as heat
Understand how some compounds (e.g. cyanide) act as inhibitors of oxidative
phosphorylation and why they can be harmful/deadly -- Answer ✔✔ -Cyanide:
Binds to protein complex IV of the ETC and prevents transfer of electrons from the
protein
-Dinitrophenol:
Lethal to humans but sold as an unregulated weight-loss product
Binds to protons (H+) and diffuses across cell membranes because the molecule is
nonpolar
Destroys proton gradient
-Oligomycin:
Antibiotic that inhibits ATP synthase by blocking its proton channel
Know where in the cell each stage takes place -- Answer ✔✔ -Glycolysis: Cytosol
-Pyruvate oxidation: Mitochondrial matrix
-Citric acid cycle: Mitochondrial matrix
-Oxidative phosphorylation: Inner mitochondrial membrane
Understand the fate of the carbons that enter the system as one 6-carbon glucose --
Answer ✔✔ Glucose → pyruvates → acetyl-CoA → CO2
-A 6-carbon glucose molecule is split into two 3-carbon molecules called pyruvates
-Pyruvate is needed in order to create acetyl CoA
-The 3-carbon pyruvate molecule made in glycolysis loses a carbon to produce a new, 2-
carbon molecule called acetyl CoA
-The carbon that is removed takes two oxygens from pyruvate with it, and exits the
body as carbon dioxide
-CO2 is the waste product that you release when you exhale
Identify the electron carriers (NADH and FADH2) and understand the general flow of
electrons through each stage -- Answer ✔✔ -Glycolysis: NADH is an output and goes
to the final stage
-Pyruvate oxidation: NADH is an output and goes to the final stage
-Citric acid cycle: NADH and FADH2 are outputs and go to the final stage
-Oxidative phosphorylation: NADH and FADH2 are inputs
Identify the final (terminal) electron acceptor of the mitochondrial electron transport
chain and understand its essential role in aerobic respiration -- Answer ✔✔ -Oxygen
-Without oxygen, ATP levels drop quickly, and we die
Understand how the electron transport chain creates a proton gradient -- Answer ✔✔ -
Proton pumping
-The proton gradient produced by proton pumping during the electron transport chain
is used to synthesize ATP
, Know how the proton gradient drives the synthesis of ATP via the protein ATP
synthase (the spinning turbine) -- Answer ✔✔ Protons flow down their concentration
gradient into the matrix through the membrane protein ATP synthase, causing it to spin
(like a water wheel) and catalyze conversion of ADP to ATP.
Understand the roles of active transport and passive transport (facilitated diffusion)
across the inner mitochondrial membrane during oxidative phosphorylation -- Answer
✔✔ -Active transport: movement of protons from the mitochondrial matrix to the
intermembrane space
-Passive transport: the movement of protons through the mitochondrial ATP synthase
occur
Relative amounts of ATP production in respiration -- Answer ✔✔ -Glycolysis = a little
ATP
-Pyruvate oxidation = no ATP
-Citric acid cycle = a little ATP
-Oxidative phosphorylation= lots of ATP; most ATP is made here
Explain how the uncoupling protein results in in the production of heat instead of ATP
in brown fat cells -- Answer ✔✔ -It provides a channel across the membrane through
which protons (H+) flow back into the matrix
-Protons don't cross the membrane via ATP synthase → almost no ATP is made
-Energy is released as heat
Understand how some compounds (e.g. cyanide) act as inhibitors of oxidative
phosphorylation and why they can be harmful/deadly -- Answer ✔✔ -Cyanide:
Binds to protein complex IV of the ETC and prevents transfer of electrons from the
protein
-Dinitrophenol:
Lethal to humans but sold as an unregulated weight-loss product
Binds to protons (H+) and diffuses across cell membranes because the molecule is
nonpolar
Destroys proton gradient
-Oligomycin:
Antibiotic that inhibits ATP synthase by blocking its proton channel
