UNC BIOL 252 Exam 2 ACTUAL Exam
Questions and CORRECT Answers
How do cells generate energy - CORRECT ANSWER - ATP
ATP is used to drive energetically _____ reactions in ______ reactions - CORRECT
ANSWER - Unfavorable (such as molecular synthesis, active transport, motility)
Coupled
What must delta g be in order for a reaction to occur - CORRECT ANSWER - negative!
What are the 4 major pathways involved in producing ATP in eukaryotic cells? - CORRECT
ANSWER - Glycolysis, Krebs cycle, Electron Transport, and Oxidative Phosphorylation
What are the reactants and products in Glycolysis? - CORRECT ANSWER - Reactants:
glucose, ADP, H+, NAD+
Products: Pyruvate, ATP, and NADH
What are the reactants and products in the Krebs Cycle? - CORRECT ANSWER -
Reactants: Pyruvate, NAD+, FAD, GDP
Products: CO2, GTP, FADH, NADH
What are the reactants and products of the Electron Transport chain? - CORRECT
ANSWER - Reactants: NADH, FADH2, O2
Products:H2O
What are the reactants and products of oxidative phosphorylation? - CORRECT
ANSWER - Reactants: H+. ADP
Products: ATP
,How do we determine where in the cell each of these pathways occur? - CORRECT
ANSWER - People have fractionated the cell. They then took those fractions, and had
many test tubes with different organelles and the cytosol. For example there might be a tube
enriched in cytosol, another in mintochondria and so on. Then they observed what happened in
these tubes when a specific set of reactants for a pathway were added, Then they assayed for
ATP, to see where it was produced.
Where does glycolysis occur - CORRECT ANSWER - ATP is produced only in the
cytosolic fraction when ADP, inorganic phosphate (Pi), H+, O2, and glucose were added to the
different fractions. Therefore glycolysis occurs in the cytosol
Where does the Krebs cycle, electron transport, and oxidative phosphorylation take place? -
CORRECT ANSWER - ATP is produced only in the mitochondrial fraction when pyruvate
instead of glucose was added to the different fractions. Therefore all of these occur in the
mitochondria
How many membrane bound components does the mitochondria contain? - CORRECT
ANSWER -2
How can we determine where in the mitochondrion the Krebs cycle takes place? - CORRECT
ANSWER - Scientists have deduced the structure of mitochondria to contain an inner and
outer membrane in btwn which there is an intermembrane space. Inside there is also the
mitochondrial matrix. As this has been determined mitochondria is now able to be placed in a
hypotonic (low salt) solution causing it to swell and the outer membrane to burst. If done
carefully then one can stop the inner membrane from bursting and can exploit this for fractions
of components. Pyruvate consumption seems to only happen in the mitochondrial matrix
therefore suggesting that the Krebs cycle takes place in the mitochondrial matrix.
Where do E.T. and O.P. occur? - CORRECT ANSWER - When people took the inner
membranes they would support Electron Transport and Oxidative Phosphorylation but when they
fractionated the inner membranes and there were shenanigans (quizlet wouldn't let me say funky
sh** happened)
What did scientists find when the inner membrane of mitochondria was fractionated in respect to
E.T. and O.P. - CORRECT ANSWER - There were little stalks on the membrane.
,How did ATP and O2 consumption change when scientists exposed the following
inner membrane with stalks
inner membrane with no stalks
unsealed membrane with stalk
unsealed membrane with no stalk
stalks alone, no membrane present - CORRECT ANSWER - ATP and O2 consumption
represented respectively
inner membrane with stalks + +
inner membrane with no stalks - +
unsealed membrane with stalk - +
unsealed membrane with no stalk - +
stalks alone, no membrane present - -
What does the E.T chain depend on - CORRECT ANSWER - The inner membrane
What does O.P. need? - CORRECT ANSWER - A sealed vesicle with stalks as that is the
only one that makes ATP
How does the E.T.C work? - CORRECT ANSWER - The ETC chain takes place in the
inner membrane where high energy electrons are taken and low energy electrons are released.
This results in pumping of protons (H plus) across the membrane. Protons then get concentrated
in the intermembrane space.
How does one measure the concentration of protons in the intermembrane space? - CORRECT
ANSWER - By measuring the pH
What is the complex called by which protons flow back through? - CORRECT
ANSWER - ATP synthase
, What type of gradient is created by ETC and how does this spur OP - CORRECT
ANSWER - Elctrochemical gradient is created by ETC, protons flow down the gradient
and then go through ATP synthase (wheel that rotates) this causes ATP synthesis, which is the
premise of O.P.
ETC in detail - CORRECT ANSWER - ...
NADH what happened - CORRECT ANSWER - NADH goes to NAD+
NADH is an electron carrier with 2 electrons. When the reaction takes place a hydride ion is
released and so are 2 electrons
NADH dehydrogenase complex - CORRECT ANSWER - Takes the hydride ion and
pumps it across the membrane
Ubiquinone - CORRECT ANSWER - Accepts the 2 electrons.
This is a protein that sits in the bilayer, it diffuses in the complex until it bumps into cytochrome
b-c complex.
cytochrome b-c complex - CORRECT ANSWER - Electrons are transferred from
ubiquinone . This then results in proton transfer to the intermembrane space
Cytochrome C - CORRECT ANSWER - Electrons are now transferred to this
unrelated but important to note leaks out when mitochondria breaks and signals cell death when
it leaks out
Cytochrome Oxidase complex - CORRECT ANSWER - Electrons are then transferred
here and a proton is pumped into the intermembrane space.
Water - CORRECT ANSWER - 2 H+ -> H20
Questions and CORRECT Answers
How do cells generate energy - CORRECT ANSWER - ATP
ATP is used to drive energetically _____ reactions in ______ reactions - CORRECT
ANSWER - Unfavorable (such as molecular synthesis, active transport, motility)
Coupled
What must delta g be in order for a reaction to occur - CORRECT ANSWER - negative!
What are the 4 major pathways involved in producing ATP in eukaryotic cells? - CORRECT
ANSWER - Glycolysis, Krebs cycle, Electron Transport, and Oxidative Phosphorylation
What are the reactants and products in Glycolysis? - CORRECT ANSWER - Reactants:
glucose, ADP, H+, NAD+
Products: Pyruvate, ATP, and NADH
What are the reactants and products in the Krebs Cycle? - CORRECT ANSWER -
Reactants: Pyruvate, NAD+, FAD, GDP
Products: CO2, GTP, FADH, NADH
What are the reactants and products of the Electron Transport chain? - CORRECT
ANSWER - Reactants: NADH, FADH2, O2
Products:H2O
What are the reactants and products of oxidative phosphorylation? - CORRECT
ANSWER - Reactants: H+. ADP
Products: ATP
,How do we determine where in the cell each of these pathways occur? - CORRECT
ANSWER - People have fractionated the cell. They then took those fractions, and had
many test tubes with different organelles and the cytosol. For example there might be a tube
enriched in cytosol, another in mintochondria and so on. Then they observed what happened in
these tubes when a specific set of reactants for a pathway were added, Then they assayed for
ATP, to see where it was produced.
Where does glycolysis occur - CORRECT ANSWER - ATP is produced only in the
cytosolic fraction when ADP, inorganic phosphate (Pi), H+, O2, and glucose were added to the
different fractions. Therefore glycolysis occurs in the cytosol
Where does the Krebs cycle, electron transport, and oxidative phosphorylation take place? -
CORRECT ANSWER - ATP is produced only in the mitochondrial fraction when pyruvate
instead of glucose was added to the different fractions. Therefore all of these occur in the
mitochondria
How many membrane bound components does the mitochondria contain? - CORRECT
ANSWER -2
How can we determine where in the mitochondrion the Krebs cycle takes place? - CORRECT
ANSWER - Scientists have deduced the structure of mitochondria to contain an inner and
outer membrane in btwn which there is an intermembrane space. Inside there is also the
mitochondrial matrix. As this has been determined mitochondria is now able to be placed in a
hypotonic (low salt) solution causing it to swell and the outer membrane to burst. If done
carefully then one can stop the inner membrane from bursting and can exploit this for fractions
of components. Pyruvate consumption seems to only happen in the mitochondrial matrix
therefore suggesting that the Krebs cycle takes place in the mitochondrial matrix.
Where do E.T. and O.P. occur? - CORRECT ANSWER - When people took the inner
membranes they would support Electron Transport and Oxidative Phosphorylation but when they
fractionated the inner membranes and there were shenanigans (quizlet wouldn't let me say funky
sh** happened)
What did scientists find when the inner membrane of mitochondria was fractionated in respect to
E.T. and O.P. - CORRECT ANSWER - There were little stalks on the membrane.
,How did ATP and O2 consumption change when scientists exposed the following
inner membrane with stalks
inner membrane with no stalks
unsealed membrane with stalk
unsealed membrane with no stalk
stalks alone, no membrane present - CORRECT ANSWER - ATP and O2 consumption
represented respectively
inner membrane with stalks + +
inner membrane with no stalks - +
unsealed membrane with stalk - +
unsealed membrane with no stalk - +
stalks alone, no membrane present - -
What does the E.T chain depend on - CORRECT ANSWER - The inner membrane
What does O.P. need? - CORRECT ANSWER - A sealed vesicle with stalks as that is the
only one that makes ATP
How does the E.T.C work? - CORRECT ANSWER - The ETC chain takes place in the
inner membrane where high energy electrons are taken and low energy electrons are released.
This results in pumping of protons (H plus) across the membrane. Protons then get concentrated
in the intermembrane space.
How does one measure the concentration of protons in the intermembrane space? - CORRECT
ANSWER - By measuring the pH
What is the complex called by which protons flow back through? - CORRECT
ANSWER - ATP synthase
, What type of gradient is created by ETC and how does this spur OP - CORRECT
ANSWER - Elctrochemical gradient is created by ETC, protons flow down the gradient
and then go through ATP synthase (wheel that rotates) this causes ATP synthesis, which is the
premise of O.P.
ETC in detail - CORRECT ANSWER - ...
NADH what happened - CORRECT ANSWER - NADH goes to NAD+
NADH is an electron carrier with 2 electrons. When the reaction takes place a hydride ion is
released and so are 2 electrons
NADH dehydrogenase complex - CORRECT ANSWER - Takes the hydride ion and
pumps it across the membrane
Ubiquinone - CORRECT ANSWER - Accepts the 2 electrons.
This is a protein that sits in the bilayer, it diffuses in the complex until it bumps into cytochrome
b-c complex.
cytochrome b-c complex - CORRECT ANSWER - Electrons are transferred from
ubiquinone . This then results in proton transfer to the intermembrane space
Cytochrome C - CORRECT ANSWER - Electrons are now transferred to this
unrelated but important to note leaks out when mitochondria breaks and signals cell death when
it leaks out
Cytochrome Oxidase complex - CORRECT ANSWER - Electrons are then transferred
here and a proton is pumped into the intermembrane space.
Water - CORRECT ANSWER - 2 H+ -> H20
