problem roulette exam 4 Flashcards
Which of the following dehydrogenation reactions do NOT contribute NADH to Complex I?
Isocitrate dehydrogenase
a-ketoglutarate dehydrogenase
Malate dehydrogenase
acyl-CoA dehydrogenase
glutamate dehydrogenase
acyl-CoA dehydrogenase
Which enzyme passes electrons directly or indirectly to coenzyme Q without pumping protons?
Glycerol-3-phosphate dehydrogenase
All options are correct
Succinate dehydrogenase
Acyl-CoA dehydrogenase
All options are correct
From the choices below, select the one which is NOT shared between oxidative phosphorylation and photophosphorylation
involvement of cytochromes.
proton pumping across a membrane to create electrochemical potential.
use of iron-sulfur proteins.
chlorophyll.
participation of quinones.
chlorophyll
The action of the enzyme that catalyzes this reaction (in the direction indicated) is likely to be fully active in the ________ during __________.
The liver, after a meal
The liver, starvation
The muscle, starvation
The liver, intense exercise
The muscle, intense exercise
Submit
The liver, after a meal
Glutamate is metabolically converted to α-ketoglutarate and NH4+ by a process described as:
deamination.
oxidative deamination.
transamination.
reductive deamination.
hydrolysis.
oxidative deamination.
Fully reduced Electron Transferring Flavoprotein passes its electrons to Coenzyme Q. In what metabolic pathway was ETF reduced by an adenine nucleotide electron carrier?
Glyoxylate Pathway
Pentose Phosphate Pathway
Glycolysis
Beta-oxidation of fatty acids
Kreb’s Cycle
Beta-oxidation of fatty acids
Under times of metabolic stress, what is the correct order of use of BioMolecules in catabolic pathways to ensure enough energy is produced to get through the stress?
Monosaccharides, fatty acids, polysaccharides, amino acids, triglycerides
Polysaccharides, monosaccharides, triglycerides, amino acids.
Fatty acids, monosaccharides, triglycerides, amino acids
Fatty acids, monosaccharides, polysaccharides, amino acids, proteins
Monosaccharides, polysaccharides, triglycerides, amino acids.
Monosaccharides, polysaccharides, triglycerides, amino acids.
During oxidative phosphorylation, the proton motive force that is generated by electron transport is used to:
reduce O2 to H2O.
generate the substrates (ADP and Pi) for the ATP synthase.
create a pore in the inner mitochondrial membrane.
induce a conformational change in the ATP synthase.
oxidize NADH to NAD+.
induce a conformational change in the ATP synthase.
in the mitochondria a motive force for ATP/ADP exchange is the __________ and for importing inorganic phosphate into the matrix is the ___________.
membrane potential (negative in the matrix), proton gradient
Where in the chloroplast is Plastocyanin located?
On the lumenal side of the stromal membranes
On the stromal side of the membranes
On the outside of the outer membrane
On the Inside of the outer membrane
On the cytoplasmic side of the chloroplast
On the lumenal side of the stromal membranes
How many carbon dioxide molecules are fixed in the Calvin Cycle in order to produce one glyceraldehyde 3-phosphate?
3
1
None, the Calvin Cycle does not fix carbon
2
4
3
Which of the following statements about aminotransferases is true?
The PLP cofactor alone can accelerate the rate of the reaction almost as much as the full PLP-enzyme complex
The aminotransferase reaction is essentially irreversible
The enzyme requires that both the donor amino acid and the acceptor a-ketoacid are bound simultaneously
A single aminotransferase is able to catalyze amino group transfer to a-ketoglutarate from any of the 20 amino acids
PLP is covalently linked to the enzyme for the entire reaction cycle
The PLP cofactor alone can accelerate the rate of the reaction almost as much as the full PLP-enzyme complex
The active site of the first enzyme in carbon fixation in C3 plants coordinates a magnesium ion. Which amino acid is NOT involved in this coordination?
All of these amino acids coordinate the magnesium.
His
Lys
Asp
Glu
His
During the initial charging step of fatty synthesis, a(n) ________ group is covalently linked to a _________ of acyl carrier protein.
Malonyl; biotin prosthetic group
Malonyl; cysteine
Acetyl; cysteine
Malonyl; phosphopantetheine prosthetic group
Acetyl; biotin prosthetic group
Acetyl; phosphopantetheine prosthetic group
Malonyl; phosphopantetheine prosthetic group
In the bacterial pheophtyin-quinone reaction centers, how are P870’s electrons replaced?
From a tyrosine radical
Oxidation of H2S
Oxidation of water by the oxygen-evolving complex
Oxidation of NADH
They do not have to be replaced because this reaction center is in a cyclic electron transfer pathway.
They do not have to be replaced because this reaction center is in a cyclic electron transfer pathway.
Which prosthetic group is found on all aminotransferases?
Thiamine pyrophosphate (TPP)
Flavin mononucleotide (FMN)
Flavin adenine nucleotide (FAD)
Lipoate
Pyridoxal phosphate (PLP)
Pyridoxal phosphate (PLP)
Glutamine synthetase converts _____ to _____ whereas glutamate synthase converts ____ to _____.
glutamate; glutamine; α-ketoglutarate; glutamate
asparagine; glutamine; α-ketoglutarate; glutamate
α-ketoglutarate; glutamine; oxaloacetic acid; glutamate
α-ketoglutarate; glutamine; α-ketoglutarate; glutamate
formate; glutamine; ammonia; glutamate
Submit
glutamate; glutamine; α-ketoglutarate; glutamate
If all the Acytyl-CoA used to synthesize a palmitate (C16) fatty acid are in the mitochondria, there will be an additional expense in fatty acid synthesis of up to ________.
2 ATP
8 ATP
16 ATP
7 ATP
14 ATP
16 ATP
Cholesterol is synthesized from:
lipoic acid.
malate.
choline.
oxalate.
acetyl-CoA.
acetyl-CoA.
Which of the following electron carriers is lipid soluble?
All of these
Plastocyanin
Flavin nucleotides
Ubiquinone
Cytochrome c
Ubiquinone
In the mitochondrial shuttles, NADH and acetyl-CoA are carried across the mitochondrial membrane as “equivalents.” NADH is carried across the membrane as _________, and acetyl-CoA is carried across the membrane as _______.
citrate; malate
malate; pyruvate
pyruvate; citrate
citrate; malate
malate; citrate
Submit
malate; citrate
All aminotransferases have the same prosthetic group. Please identify it from the list below.
FAD
Vitamin B12
Coenzyme A
Biotin
Pyridoxal phosphate
Pyridoxal phosphate
Which of the following is NOT required for the synthesis of Cholesterol from its initial precursor?
Coenzyme A
NADPH
ATP
Carbon dioxide
Carbon dioxide
What is the important intermediate at a branch point that leads to either AMP or GMP synthesis?
AICAR
Inosinate
Folate
Chorismate
Xanthylate
Inosinate
The first intermediate in cholesterol synthesis which contains all the carbon atoms which will eventually form the four fused ring cholesterol backbone is
Activated Isoprene
acetyl-CoA
squalene
mevalonate
lanosterol
squalene
The following enzyme in the palmitate synthesis pathway is positively regulated by citrate:
HMG-CoA reductase
Acetyl-CoA carboxylase
Malonyl/Acetyl-CoA-ACP transferase
Enoyl-ACP reductase
Ketoacyl synthase
Acetyl-CoA carboxylase
Which of the following molecules are negative regulators of fatty acid synthesis?
Citrate
Epinephrine
Palmityl-CoA
II and III only
None of these
I only
I and II only
III only
II and III only
The following molecules are produced by the first phase of the Q cycle:
Ubiquinol (fully reduced)
Semiquinone radical
Ubiquinone (fully oxidized)
II and III only
I only
I, II, and III
I and II only
I and III only
II and III only
When the [NADPH]/[NADP+] ratio in plants is high, photophosphorylation is primarily cyclic. What is/are the major product(s) of photophosphorylation in this circumstance?
ATP + NADPH
ATP
O2
NADPH
ATP
After each round of acyl chain elongation, the new acyl chain moves from
Detroit to Miami Beach when the snow starts
ACP to KS
Acetyl CoA to Malonyl CoA
ACP to Malonyl CoA
KS to ACP
ACP to KS
In cholesterol synthesis, the first molecule in the synthetic pathway that possesses a sterol nucleus is:
Lanosterol
Isoprene
Mevalonate
Squalene
Cholesterol
Lanosterol
Which of the following is involved in mitochondrial electron transport and not in electron transport in chloroplasts?
Cytochrome c oxidase
Plastoquinone
Cytochrome B6/f
Coenzyme Q
Iron-Sulfur Centers (Clusters)
Cytochrome c oxidase
Which of the following would NOT supply NADPH (from NADP+) that could be used for anabolic pathways?
Malic Enzyme
All of the above produce NADPH
Beta-Oxidation
Photosynthesis
Pentose Phosphate Pathway
Beta-Oxidation
Head-group Exchange is a strategy used for the synthesis of
Membrane phospholipids
Leukotrienes
Cholesterol
Triacylglycerols
Palmitate
Membrane phospholipids
In Photosystem II, which of the following directly oxidizes the Mn4CaO5 cluster?
A tyrosine radical
Water
A special chlorophyll in the P680 reaction center
An exciton
Oxygen (O2)
A tyrosine radical
What prosthetic group is required by acetyl-CoA carboxylase, covalently linked to a Lys residue?
Vitamin B12
Biotin
FADH2
Cardiolipin
Tetrahydrofolate
Biotin
Which of the following chemical transformations regulates Rubisco?
Decarboxylation
Phosphorylation/dephosphorylation
Reduction/Oxidation
Carbamoylation
Protonation
Carbamoylation
Coenzyme Q and cholesterol synthesis share which common precursor?
Squalene
NADH
Malonyl-CoA
Activated Isoprene
Lanosterol
Activated Isoprene
The fixation of atmospheric nitrogen is costly with respect to energy, and only certain organisms undergo nitrogen fixation. How many molecules of ATP are required to fix one N2 into 2 NH4+?
4
2
32
8
16
16
The synthesis of arginine starts with the amino acid , and uses reactions from the .
glutamine; citric acid cycle
glutamine; urea cycle
glutamate; urea cycle
glutamate; citric acid cycle
glutamate; glyoxylate cycle
glutamate; citric acid cycle
Succinate dehydrogenase is dysfunctional in a species of garden slug. While its metabolism is compromised on a number of levels, it can still undergo oxidative phosphorylation. What is the maximal P/O ratio for these organisms if NADH is used as an electron source?
1.5
1
2
4
2.5
2.5
Which of the following enzymes is present in the Calvin cycle, but not present in either glycolysis or the pentose phosphate pathway?
Aldolase
Transketolase
Ribulose 5-phosphate kinase
Phosphoglycerate kinase
Transaldolase
Ribulose 5-phosphate kinase
For the synthesis of one molecule of palmitate, the fatty acid synthase complex (in isolation) consumes the following reagents:
8 malonyl CoA, 14 NADPH
1 acetyl CoA, 7 malonyl CoA, 16 NADPH
1 acetyl CoA, 7 malonyl CoA, 14 NADPH
8 acetyl CoA, 14 NADPH
8 malonyl CoA, 16 NADPH
1 acetyl CoA, 7 malonyl CoA, 14 NADPH
Which of the following is a role for the transmembrane domain of the ATP Synthase at the end of the Respiratory Chain?
Contains the ADP/ATP binding site
Contains the catalytic domain for the ATPase
Contains the FMN that provides protons for ATP synthesis
Contains the proton pore
Contains the electron transport pore
Contains the proton pore
Many plants synthesize several different photopigments. With respect to photophosphorylation, the reason for this is:
Photopigments with different absorption maxima can absorb photons from the entire visible spectrum
If the reactants to synthesize chlorophyll are not available, other photopigments can replace chlorophyll in the photosystems
This provides several alternate routes of electron entry to the photosystems
Plants synthesize different photopigments depending on the nutrients available
The different standard reduction potentials of different photopigments allow them to operate under a variety of different redox conditions
Photopigments with different absorption maxima can absorb photons from the entire visible spectrum
The Oxygen Evolving Complex produces ____ electrons and pumps ____ H+ into the thylakoid lumen for every O2 produced.
2, 8
4, 4
8, 8
4, 2
2, 4
4, 4
Consider the following diagram showing feedback inhibition in the biosynthesis of amino acids. Which of the following types of regulation are observed in the lysine biosynthesis pathway?
Concerted inhibition
Sequential inhibition
Enzyme multiplicity
I and III
III only
I and II
I only
I, II and III
I, II and III
What structure, molecule or system replenishes the “electron hole” created in the P680 Reaction Center due to exciton transfer?
P700
FADH2
NADH
Oxygen evolving complex
Ferridoxin
Oxygen evolving complex
The following enzyme is the most important site of regulation for fatty acid biosynthesis:
Acetyl-CoA carboxylase
Ketoacyl reductase
Ketoacyl synthase
Malonyl/Acetyl-CoA-ACP transferase
Enoyl-ACP reductase
Acetyl-CoA carboxylase
The carbon skeletons of ketogenic amino acids may be incorporated directly into ____________, whereas the carbon skeletons of glucogenic amino acids may be incorporated directly into _____________.
LaTeX: \alphaα
-Ketoglutarate; Citrate and Malate
Malonyl-CoA; Citrate and DHAP
LaTeX: \alphaα
-Ketoglutarate; Acetyl-CoA
Succinyl-CoA and LaTeX: \alphaα
-Ketoglutarate; Acetyl-CoA
Acetyl-CoA; Succinyl-CoA and LaTeX: \alphaα
-Ketoglutarate
Acetyl-CoA; Succinyl-CoA and α
-Ketoglutarate
Which important intermediate of cholesterol synthesis, beginning with acetate, is itself transformed by three successive phosphoryl group transfer reactions?
Acetoacetyl-CoA
Isoprenes
Mevalonate
Squalene
Lanosterol
Mevalonate
CMP, UMP, and TMP all have _____ as a common precursor.
glutamine
aspartate
adenosine
inosine
S-adenosyl methionine
aspartate
Which of the following terms describes leptin?
Steroid hormone
Paracrine hormone
Eicosanoid hormone
Autocrine hormone
Endocrine hormone
Endocrine hormone
Free nitrogen (ammonia) can be incorporated into ___________ yielding __________ at a cost of ______________.
alpha -ketoglutarate, glutmate, 1 ATP
aspartate, asparagine, 1 ATP
glutamine, glutamate, 1 ATP
glutamate, glutamine, 1 ATP
glutamate, glutamine, 1 NAD(P)H
glutamate, glutamine, 1 ATP
If all the electrons used in the reductive steps of the synthesis of a palmitate (C16) fatty acid were instead fed into the respiratory chain for ATP synthesis, there could be a net production of up to _______ ATP.
20
17.5
35
40
28
35
Which of the following amino acids is the main carrier of nitrogen through the bloodstream during normal metabolic load?
Glu
Asn
Gln
Arg
Ala
Gln
In the urea cycle, fumarate is produced by the following enzyme:
Arginase
Argininosuccinate synthetase
Argininosuccinase
Carbamoyl phosphate synthetase
Ornithine transcarbamoylase
Argininosuccinase
Which of the following molecules in photophosphorylation is NOT an integral membrane protein?
Light Harvesting Complex
Photosystem I
Photosystem II
Cytochrome b6f complex
Plastocyanin
Plastocyanin
Which of the following statements describes insulin?
A “bottom-up” metabolic regulator that leads to a decrease in blood glucose levels
A peptide hormone that signals that blood glucose is low
A “top-down” metabolic regulator that leads to a decrease in blood glucose levels
A “bottom-up” metabolic regulator that signals that blood glucose is low
A “top-down” metabolic regulator that leads to an increase in blood glucose levels
A “bottom-up” metabolic regulator that leads to a decrease in blood glucose levels
Amytal is a barbituate that inhibits Complex I of the electron transport chain. Which of the following might happen if amytal is present in mitochondria:
Increased levels of NADH
ATP is not synthesized
QH2 is not produced
II and III only
II only
I, II, and III
I and II only
I only
I only
Pyrimidine nucleotides are synthesized de novo from what amino acid and using what extra source of energy?
Asp and ATP
Asn and NADPH
Ser and ATP
Glu and NADH
Asp and GTP
Asp and ATP
An amino acid that does not derive its carbon skeleton, at least in part, from α-ketoglutarate is:
threonine.
arginine.
proline.
glutamate.
glutamine.
threonine.
Electrons in photosystem I come from _____; electrons in photosystem II come from _____.
O2; Photosystem I
H2O; Photosystem I
Photosystem II; H2O
Photosystem II; O2
NADPH, Photosystem 1
Photosystem II; H2O
On which side of the chloroplast membrane is the ATP Synthase active site?
On the cytoplasmic side
On the lumenal side of the stromal membranes
On the Inside of the outer membrane
On the outside of the outer membrane
On the stromal side of the membranes
On the stromal side of the membranes
The molecule exported from the mitochondria to feed into fatty acid synthesis also regulates ___________and ______________.
Fatty acid synthase and PFK-1
carnitine acyltransferase and acetyl-CoA carboxylase
Fatty acid synthase and acetyl-CoA carboxylase
PFK-1 and acetyl-CoA carboxylase
PFK-1 and carnitine acyltransferase
PFK-1 and acetyl-CoA carboxylase
The Oxygen Evolving Complex of Photophosphorylation
Uses a Manganese Complex rather than Magnesium to remove electrons from molecular oxygen
Passes 4 electrons to P680+ and passes 4 protons to the chlorplast stroma
Passes 4 electrons to P700+
Links PSII with PSI through a pair of Cytochrome molecules
Accepts electrons and produces molecular oxygen, plus pumps 4 protons to the thylakoid lumen
Accepts electrons and produces molecular oxygen, plus pumps 4 protons to the thylakoid lumen
Which of the following nucleic acid derivatives is used in large amounts for fatty acyl chain synthesis?
FMN
NADP+
NADH
ACP
NADPH
NADPH
Nitrogen disposal via the urea cycle involves the input of ATP at two places, including a key adenylyl transfer reaction. What is the enzyme that catalyzes the adenylyl transfer?
Ornithine transcarbamoylase
Carbamoyl phosphate synthetase I
Argininosuccinate synthetase
Arginosuccinase
Argininosuccinate synthetase
Some herbicides inhibit electron transfer to plastocyanin. Which of the following is a likely effect of this herbicide?
ATP synthesis continues, but NADPH is not formed
NADPH synthesis continues, but ATP is not formed
ATP synthesis and NADPH synthesis are both prevented
The oxygen-evolving complex cannot donate electrons to Photosystem II
Excessive heat is generated, causing enzyme denaturation
ATP synthesis continues, but NADPH is not formed
In certain tissues, the yield of ATP from _______________ is reduced due to the use of the ___________________ rather than the _________________ for transport of electrons into the respiratory chain.
FADH2, glycerol 3-phosphate shuttle, malate-aspartate shuttle
NADH, glycerol 3-phosphate shuttle, malate-aspartate shuttle
FADH2, malate-aspartate shuttle, glycerol 3-phosphate shuttle
NADH, malate-aspartate shuttle, glycerol 3-phosphate shuttle
NADH, glyceraldehyde-3-phoshate shuttle, malate-aspartate shuttle
NADH, glycerol 3-phosphate shuttle, malate-aspartate shuttle
Which of the following is NOT a fate of glucose-6-phosphate in the fed state?
Synthesis of ribulose-5-phosphate
Conversion to glycogen
Oxidation via glycolysis, Kreb’s cycle, and the respiratory chain
Dephosphorylation to glucose
Conversion to acetyl CoA for fatty acid synthesis
Dephosphorylation to glucose
Which of the following characterizes C4 plants?
Low starch concentration in leaf cells, low light conditions, wet and humid environment
High photorespiration rate, high metabolic rates, high water loss
Low water loss, growth in high light/tropical conditions, high photosynthetic rates
High water loss, high photosynthetic rates, high metabolic rates
Low water loss, growth in high light/tropical conditions, high photosynthetic rates
About how many protons are passively transported through the F1/Fo complex in order to phosphorylate one molecule of ADP? (Assume 9 c subunits in Fo.)
4
2
2.5
3.5
3
3
Which of the following is TRUE about the reaction shown?
This reaction takes place in the cytosol of liver cells
This reaction is catalyzed by a transcarbamoylase
The enzyme that catalyzes this reaction is not a major regulatory point
Glutamate is an allosteric activator of the enzyme that catalyzes this reaction
This reaction accounts for the consumption of half of the high energy phosphoryl groups required to convert ammonium to urea
This reaction accounts for the consumption of half of the high energy phosphoryl groups required to convert ammonium to urea
When the [NADPH]/[NADP+] ratio in plants is low, photophosphorylation is primarily non-cyclic. What is/are the major product(s) of photophosphorylation in this circumstance?
I. ATP
II. NADPH
III. O2
All of these
II and III
I only
II only
I and III
II and III
For which group of molecules below is Inosinate (IMP) an important intermediate?
Amino Acids derived from 3-phosphoglycerate
the deoxyribonucleic acids
Purine nucleotides
Pyrimidine nucleotides
Amino acids derived from alpha-ketoglutarate
Purine nucleotides
Consider the following Z-diagram. Which of the following statements is NOT true?P680* has a higher electron affinity than P700*
The manganese cluster of the oxygen complex can be oxidized four times before it oxidizes water
Pheophytin (pheo) has a higher electron affinity than plastocyanin
Δ G of electron transfer from Fd to cytochrome b6f complex is negative
Without absorption of a photon, promotion of an electron from P680 to P680* would have a positive Δ G
Pheophytin (pheo) has a higher electron affinity than plastocyanin
If an uncoupler is added to the mitochondrial membrane, which of the following would NOT be an expected consequence?
An increase in temperature
An increase in the electrical potential across the mitochondrial membrane
A decrease in the measured P/O ratio
An increase in oxygen utilization
A decrease in the amount of ATP produced per mole of glucose consumed
An increase in the electrical potential across the mitochondrial membrane
Place the following electron-carriers into the proper order as found in plant chloroplasts.
1) Cytochrome b6f complex
2) Plastocyanin
3) P700
4) P680
5) NADPH
2, 1, 3, 4, 5
4, 2, 5, 1, 3
1, 3, 4, 2, 5
4, 1, 2, 3, 5
3, 2, 4, 1, 5
4, 1, 2, 3, 5
What is the P/O ratio for mitochondrial oxidation using NADH?
2
1.5/2/.5
2.5
3
3/2
2.5
The urea cycle involves the movement of the following two molecules across the mitochondrial membrane:
Carbamoyl phosphate and ornithine
Arginine and ornithine
Citrulline and ornithine
Carbamoyl phosphate and citrulline
Citrulline and arginine
Citrulline and ornithine
Expressing thermogenin (UCP1) generates heat because:
None of the options are correct.
It uncouples electron transport from pumping protons, causing the electrons to release their potential energy as heat.
It uncouples F1 and Fo causing rapid ATP hydrolysis which releases heat.
It uncouples Oxygen reduction from proton transport.
It uncouples proton transport from ATP production, causing the protons to release their potential energy as heat.
It uncouples proton transport from ATP production, causing the protons to release their potential energy as heat.
Fatty acid synthesis requires _____________ for each round, while beta oxidation yields _______________ for each round.
NADPH; FADH2
NADPH; NADH
2 NADPH; 1 FADH2 and 1 NADH
1 FADH2 and 1 NADH; 2 NADH
2 NADH; 1 FADH2 and 1 NADPH
2 NADPH; 1 FADH2 and 1 NADH
What is the result of activation of Complex I of the Respiratory Chain?
4 Protons are pumped from the intermembrane space to the Matrix
NADH gets reduced
Electrons accepted from NADH are passed to FAD
QH2 becomes oxidized
4 protons are pumped from the matrix to the intermembrane space
4 protons are pumped from the matrix to the intermembrane space
_______________ are synthesized as inactive _______________ and secreted to the stomach where _____________ activates them for degradation of dietary amino acids.
proteases, zymogens, phosphorylation
proteases, zymogens, low pH
zymogens, proteases, low pH
zymogens, proteases, high pH
proteases, zymogens, phosphorylation
proteases, zymogens, low pH
Carbamoyl phosphate is an important intermediate in the synthesis of which of the following groups of molecules?
Amino acids derived from Pyruvate
Aromatic amino acids
Deoxyribonucleotides
Pyrimidines
Purines
Pyrimidines
The cellular ATP/ADP ratio controls the rate of:
Oxidative phosphorylation
The TCA cycle
Glycolysis
I and II
I and III
I, II and III
I only
II and III
I, II and III
Chemical uncouplers of photophosphorylation have been identified. Like mitochondrial uncouplers, these agents cause an increase in temperature of plant tissue. Which of the following is another likely metabolic consequence of a partial uncoupler of photophosphorylation:
NADPH synthesis is halted
Protons accumulate in the thylakoid lumen
Via regulatory mechanisms, the plant increases the ratio of cyclic to non-cyclic pathways
Protons move more rapidly from stroma to the thylakoid lumen
Oxygen consumption increases
Via regulatory mechanisms, the plant increases the ratio of cyclic to non-cyclic pathways
The major pathways of Ammonium Assimilation lead to the synthesis of which one of the following amino acids?
Ser
Phosphoenolpyruvate
Gly
Asp
Gln
Gln
The Glucose-Alanine Cycle performs what specific role in metabolism?
Transport of Urea to the Urinary tract
Production of ATP and NADH when the Citric Acid Cycle is low on intermediates
Catabolism of Glucose to produce the precursors for several amino acids, including Ala
Transport of amino groups to the liver in a non-toxic form
Transfer of Ala to smooth muscle where it is converted to Oxaloacetate
Transport of amino groups to the liver in a non-toxic form
What molecule is central to carbohydrate (i.e. sugar) metabolism in the liver, being at a crossroads of at least 5 important possible fates and whose concentration controls regulatory enzyme activity in each of those fates?
Glutamate
Acetate
Glucose 6-phosphate
NADPH
ATP
Glucose 6-phosphate
Which of the following statements about aminotransferases is true?
PLP is covalently linked to the enzyme for the entire reaction cycle
The PLP cofactor is always bound to the enzyme with a covalent bond
A single aminotransferase is able to catalyze amino group transfer to a-ketoglutarate from any of the 20 amino acids
The enzyme requires that both the donor amino acid and the acceptor a-ketoacid are bound simultaneously
The aminotransferase reaction is readily reversible
The aminotransferase reaction is readily reversible
How many malonyl-CoA and acetyl-CoA are necessary to produce 1 molecule of Palmitate?
1 Malonyl-CoA and 7 Acetyl-CoA
7 Malonyl-CoA and 7 Acetyl-CoA
7 Malonyl-CoA and 1 Acetyl-CoA
1 Malonyl-CoA and 8 Acetyl-CoA
1 Malonyl CoA and 8 Acetyl-CoA
7 Malonyl-CoA and 1 Acetyl-CoA
A new electron carrier has been discovered. It directly passes 4 electrons to ubiqinol. How many ATPs is this carrier worth when fully charged?
1.5 ATPs
3 ATPs
6 ATPs
2 ATPs
2.5 ATPs
3 ATPs
Malonyl-CoA for acyl chain synthesis is produced by acetyl-CoA carboxylase. What prosthetic group is required for this enzyme?
NADH
Biotin
Transcobalamin
Magnesium
Thiamine pyrophosphate
Biotin
The component of plant reaction centers which is most analogous in function to Complex III in oxidative phosphorylation is:
Plastocyanin
Ferredoxin:NADP oxidoreductase
Cytochrome b6f complex
pheophytin
Cytochrome c2
Cytochrome b6f complex
What is the result of one round of electron transport by Complex I of the Respiratory Chain?
QH2 becomes oxidized
NADH gets reduced
4 Protons are pumped from the Intermembrane space to the Matrix
4 protons are pumped from the Matrix to the intermembrane space
Electrons accepted from NADH are passed to FAD
4 protons are pumped from the Matrix to the intermembrane space
The compartment of the chloroplast which is analogous to the intermembrane space of the mitochondria is:
thylakoid membrane
stroma
outer membrane
thylakoid lumen
granal stacks
thylakoid lumen
What is the main regulatory mechanism on Purine Synthesis?
Feedback inhibition, mostly by monophosphates
Phosphorylation/dephosphorylation of the first enzyme of the pathway
Inhibition of the formation of AICAR
Limitation of the starting reactant, which comes from Glycolysis
Competitive inhibition by Pyrimidine diphosphates
Feedback inhibition, mostly by monophosphates
Inosinate (IMP) serves as a precursor in pathways that generate which of the following?
Asp
Fumarate
NADH
Thymidine
Cytosine
Fumarate
Which of the following is the proper order of electron transport between Photosystem II and Photosystem I in higher plant membranes?
Pheophytin, plastocyanin, plastoquinone
Plastoquinone, Cytochrome b6/f, plastocyanin
Chlorophyll a, plastocyanin, plastoquinone
Cytochrome Q, Cytochrome a, Cytochrome c
Plastocyanin, plastoquinone, iron-sulfur center
Plastoquinone, Cytochrome b6/f, plastocyanin
A transaminase uses alpha-ketoglutarate and the molecule shown below as a substrate. The products of the reaction are glutamate and ______________.Glycerate
alpha-ketoglutarate
Oxaloacete
Carbamate
Pyruvate
Pyruvate
What is the form of sulfur that is incorporated into Cys (using Serine)?
Sulfate
Sulfide
Sulfite
H2S
Sulfide
Which of the following actually leaves a Photochemical Reaction Center, a critical reaction in Photophosphorylation?
A molecule of cytochrome c
An electron
A hydride ion
A molecule of oxygen (O2)
A photon of light
An electron
Passing two electrons from glycerol-3-phosphate through the respiratory chain yields:
6 ATP
10 ATP
1.5 ATP
None of the other answers is correct
2.5 ATP
1.5 ATP
If a plant cell chloroplast has an excess of NADPH relative to ATP, it would be logical to adjust the photosynthetic pathway such that:
(Refer to the following image if necessary.)
The light harvesting complex associates more tightly with photosystem II thus favoring the noncyclic mode.
The light harvesting complex associates more tightly with photosystem II thus favoring the cyclic mode.
The light harvesting complex associates more tightly with photosystem I thus favoring the cyclic mode.
None of these other answers would apply
The light harvesting complex associates more tightly with photosystem II thus favoring the noncyclic mode.
The light harvesting complex associates more tightly with photosystem I thus favoring the cyclic mode.
The key regulatory step in cholesterol biosynthesis is catalyzed by:
Acetyl CoA carboxylase
Mevalonate 5-phosphotransferase
HMG-CoA reductase
Phosphomevalonate kinase
HMG-CoA synthase
HMG-CoA reductase
The following electron carriers are capable of transporting exactly one electron except:
Ubiquinone
FeS cluster
Cytochrome c
Plastocyanin
CuA
Ubiquinone
In fatty acid synthesis, the step catalyzed by fatty acid synthase immediately after the dehydration step is: (The squiggle indicates the covalent linkage to ACP).
For the following two half reactions:
Cytochrome c (Fe3+) + e– LaTeX: \rightarrow cytochrome c (Fe2+) E’ (V) = 0.220
FAD + 2H+ + 2e– LaTeX: \rightarrow FADH2 E’ (V) = -0.219
We would expect the spontaneous complete reaction to be:
2 Cytochrome c (Fe3+) + FADH2 -> 2 cytochrome c (Fe2+) + FAD + 2H+
Which of the following molecules is NOT used in the reaction that produces Carbamoyl Phosphate, the nitrogen carrier, in the Urea Cycle?
Bicarbonate
Ammonia
ATP
All of the above molecules are used by carbamoyl phosphate synthetase I
Coenzyme A
Coenzyme A
Which is the correct path electrons follow in the oxygen evolving complex?
H2O, Tyr, Mn, P680
H2O, Mn, Tyr, P680
O2, Tyr, Mn, P680
O2, Mn, Tyr, P680
P680, Tyr, Mn, H2O
H2O, Mn, Tyr, P680
In comparing fatty acid biosynthesis with β oxidation of fatty acids, which of the following statements is incorrect?
A thioester derivative of crotonic acid (trans-2-butenoic acid) is an intermediate in the synthetic path, but not in the degradative path.
Fatty acid biosynthesis uses NADPH exclusively, whereas β oxidation uses NAD+ exclusively.
The condensation of two moles of acetyl-CoA in the presence of a crude extract is more rapid in bicarbonate buffer than in phosphate buffer at the same pH; the cleavage of acetoacetyl-CoA proceeds equally well in either buffer.
Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by mitochondrial enzymes.
A thioester derivative of D-β-hydroxybutyrate is an intermediate in the synthetic path, not in the degradative path.
Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by mitochondrial enzymes.
What amino acid serves as a reactant in most transamination reactions for amino acid synthesis?
Ala
Arg
Gln
Gly
Glu
Glu
One amino acid directly involved in the purine biosynthetic pathway is:
tryptophan
aspartate.
glutamate.
leucine.
alanine.
aspartate
The cellular respiration rate is regulated by ADP. This is an example of which regulatory mechanism?
Sequential Inhibition
Mass action
Acceptor control
Concerted regulation
Feedback regulation
Acceptor control
For every CO2 incorporated into 3-phosphoglycerate by Rubisco, ____________ is/are consumed (not counting ribulose 1,5-bisphosphate or water).
2 ATP
no other molecules
1 NADPH
1 ATP and 1 NADPH
1 ATP
no other molecules
Which of the following is an alternative route of entry into the electron transport chain that bypasses both complex I and complex II and transfers electrons directly to ubiquinone?
Malate dehydrogenase
alpha-ketoglutarate dehydrogenase
Glyceraldehyde-3-phosphate dehydrogenase
Glycerol-3-phosphate dehydrogenase
Succinate dehydrogenase
Glycerol-3-phosphate dehydrogenase
What important intermediate is the first in the purine synthesis pathway that has a complete double ring structure?
AICAR
Acetolactate
Inosinate
Spermidine
Squalene
Inosinate
A 30-carbon precursor of the steroid nucleus is:
lysolecithin.
farnesyl pyrophosphate.
geranyl pyrophosphate.
squalene.
isopentenyl pyrophosphate.
squalene
When the following reaction occurs in peripheral tissues (non-muscle) under normal turnover of cellular amino acids (not starvation conditions), a likely fate of the product shown in the upper right is:
Oxidative deamination to immediately release the nitrogen.
Immediate entry into the Urea cycle
Incorporation of a second nitrogen (at the expense of 1 ATP) prior to export to the bloodstream.
Direct export to the bloodstream for processing in the liver
Incorporation of a second nitrogen (at the expense of 1 ATP) prior to export to the bloodstream.
Which one of these is most commonly used as a reducing agent in the cell to facilitate fatty acid synthesis?
NADP+
FADH2
NAD+
NADH
NADPH
NADPH
In amino acid catabolism, the first reaction for many amino acids is a(n):
decarboxylation requiring thiamine pyrophosphate (TPP).
hydroxylation requiring NADPH and O2.
transamination requiring pyridoxal phosphate (PLP).
reduction requiring pyridoxal phosphate (PLP).
oxidative deamination requiring NAD+.
transamination requiring pyridoxal phosphate (PLP).
Which of the following does NOT describe a physiological consequence of high blood glucagon levels?
Polymerization of fatty acid synthetase
Decreased activity of phosphofructokinase in the liver
Inhibition of acetyl-CoA carboxylase
Increased activity of glycogen phosphorylase
Glucose released to the blood
Polymerization of fatty acid synthetase
The product of arginosuccinase that does not contain nitrogen:
Directly contributes electrons to the electron transport chain
Is directly transported across the mitochondrial membrane
Directly feeds into the citric acid cycle
Can be utilized in purine biosynthesis
Can be converted into malate via the action of cytosolic fumarase for transport into the mitochondria
Can be converted into malate via the action of cytosolic fumarase for transport into the mitochondria
The synthesis of DNA requires deoxyribonucleotides derived from ribonucleotides by reduction. What molecule provides the reducing equivalents for this reaction?
FADH2
NADP+
NAD+
NADPH
NADH
NADPH
Consider the following diagram of absorption spectra of various pigments.
Which order is the most likely path for the flow of exciton transfer?
Lutein –> chlorophyll a –> chlorophyll b
Phycocyanin –> Phycoerythrin –> beta-carotene
beta-carotene –> phycoerythrin –> phycocyanin
chlorophyll b –> phycocyanin –> phycoerythrin
beta-carotene –> Lutein –> phycoerythrin
beta-carotene –> phycoerythrin –> phycocyanin
I add an inhibitor of mitochondrial respiration that prevents electron transfer to cytochrome c. Which of the following outcomes is the most likely?
Buildup of both QH2 and NADH; decreased oxygen consumption
Buildup of QH2 but not NADH, increased oxygen consumption
Normal levels of QH2 and NADH; decreased oxygen consumption
Normal levels of QH2 and NADH; increased oxygen consumption
Buildup of QH2 but not NADH; decreased oxygen consumption
Buildup of both QH2 and NADH; decreased oxygen consumption
Which pair of amino acids would you expect to have essentially identical synthesis pathways (parallel reactions, same chemistry), differing only by the identity of one of the starting substrates?
Trp, Tyr
Val, Ile
Ser, Cys
Asp, Gln
Thr, Ser
Val, Ile
The overall reaction: QH2 + 2 cyt c (ox) + 2HN+ –> Q + 2cyt c (red) + 4HP+ is catalyzed by which electron transfer complex?
Complex II
Complex IV
Complex III
ATP synthase
Complex I
Complex III
What product from glycogen catabolism in very active skeletal muscle is sent to the liver through the blood as a part of the Cori Cycle?
NADH
Lactate (or Lactic Acid)
Glucose
Ketone Bodies
ATP
Lactate (or Lactic Acid)
Which of the following statements is/are correct about purine synthesis?
I. GTP is required for the synthesis of AMP.
II. ATP is required for the synthesis of AMP.
III. GTP is required for the synthesis of GMP.
IV. ATP is required for the synthesis of GMP.
II only
IV only
III only
I only
I and IV
II and IV
I and IV
In ATP synthase, the interaction of stalk with a beta-subunit in the F1 complex contributes to ATP synthesis by:
Decreasing the free energy for formation of a phosphodiester bond between ADP and Pi
Increasing the free energy for protons to cross the membrane
Allowing the c-ring to rotate with a free energy of ~0
Increasing the free energy of ATP dissociation from the beta subunit
Decreasing the free energy of ATP dissociation from the beta subunit
Decreasing the free energy of ATP dissociation from the beta subunit
Identify the correct order of the four biochemical mechanisms that are repeated many times to produce Palmitate from Acetyl-CoA and Malonyl-CoA
Dehydration, Reduction, Condensation, Reduction
Reduction, Condensation, Reduction, Dehydration
Condensation, Reduction, Reduction, Dehydration
Reduction, Dehydration, Reduction, Condensation
Condensation, Reduction, Dehydration, Reduction
Condensation, Reduction, Dehydration, Reduction
Which of the following important intermediates of cholesterol synthesis is missing from this list taken from the four summary steps: Acetate, Squalene, Cholesterol?
CDP-choline
Methyl-malonyl-CoA
Malonyl-CoA
Mevalonate
Phosphatidic Acid
Mevalonate
The difference between C-3 and C-4 plants is
The number of steps in the Calvin Cycle in one type of plant versus the other type of plant
The number of CO2 molecules required by cells with these pathways to keep the concentration of Oxaloacetate constant in the Kreb’s Cycle
The number of carbons that are in the initial compound into which carbon is fixed
The total number of carbons that are removed as CO2 by one turn of the Calvin Cycle in each plant type
The number of carbons in the final Cycle products of Calvin Cycle for different plants
The number of carbons that are in the initial compound into which carbon is fixed
Which of the following statements best describes the reactions of the Third Stage of Carbon Assimilation?
Dihydroxyacetone phosphate is used to produce either starch or sucrose
Triose phosphates are converted to pentose phosphates
Triose phosphates are reduced to form glyceraldehyde 3-phosphate
Decarboxylation of pentose phosphates to produce oxaloacetate
Carbon dioxide is incorporated into a pentose
Triose phosphates are converted to pentose phosphates
In the Urea Cycle, ________ made in the cytosol is passed into the mitochondria, which is converted in the next step to _____________ which is then passed back to the cytosol.
Ornithine, Citrulline
Citrulline, Ornithine
Ornithine, Argininosuccinate
Ornithine, Carbamoyl phosphate
Citrulline, Carbamoyl phosphate
Ornithine, Citrulline
The strategy of using multiple isozymes to catalyze an early shared step in amino acid synthesis, each of which is subject to a unique set of allosteric effectors is referred to as:
Uncompetitive inhibition
Sequential inhibition
Enzyme multiplicity
Concerted inhibition
Feedback inhibition
Enzyme multiplicity
What is the final electron acceptor in Oxidative Phosphorylation?
Cytochrome c
Carbon dioxide
Water
Hydrides
Molecular oxygen
Molecular oxygen
Which process occurs in photosynthesis?
I. Carbon atoms in CO2 become reduced.
II. Oxygen atoms in water become oxidized.
III. NADP is reduced to NADPH by electron transport processes.
III only
II only
None of these processes occur in photosynthesis.
I only
I, II and III
I, II and III
Precursors for the biosynthesis of the pyrimidine ring system include:
glycine and succinyl-CoA.
glycine, glutamine, CO2, and aspartate.
glutamate, NH3, and CO2.
carbamoyl phosphate and aspartate.
inosine and aspartate.
carbamoyl phosphate and aspartate.
Flavin mononucleotide
Biotin
Phosphopantethiene
Pyridoxal phosphate
Lipoic Acid
Pyridoxal phosphate
If a person’s urine contains unusually high concentrations of urea, which one of the following diets has he or she probably been eating recently?
High carbohydrate, very low protein
Very low carbohydrate, very high protein
Very high carbohydrate, no protein, no fat
Very high fat, very low protein
Very very high fat, high carbohydrate, no protein
Very low carbohydrate, very high protein
Heme groups are prosthetic groups in which Complex?
F1/Fo Particles
Oxygen Evolving Complex
Complex I
Complex III
Phosphate translocase
Complex III
How many protons must be pumped across the membrane in order to make 1 molecule of ATP? (Consider all processes. Assume, as we did in class, that the c-ring of Fo has 9 subunits).
3
4
2.5
10
6
4
Cytochrome c is a mobile electron carrier that moves among Complexes of the mitochondrial electron transport chain. Which Complexes does it move between?
IV and the F1/Fo ATPase
I and III
III and IV
II and IV
II and III
III and IV
Most bacteria can synthesize all twenty amino acids. But certain mutant strains, known as “auxotrophs” are unable to synthesize a particular amino acid, and require the addition of that amino acid to their growth media in order to grow well. A glycine auxotroph would fail to synthesize glycine, as well as the following molecule:
Serine
Cytosine Nucleotides
Guanine nucleotides
Cysteine
3-phosphoglycerate
Guanine nucleotides
Reactions catalyzed by which of the following proteins do NOT contribute electron carriers to the electron transport chain?
Succinate dehydrogenase
Malate dehydrogenase
Alcohol dehydrogenase
Glucose-6-phosphate dehydrogenase
Glucose-6-phosphate dehydrogenase
The synthesis of amino acids often involves transamination reactions, resulting in the synthesis of which Kreb’s Cycle intermediate?
Alpha-ketoglutarate
Malate
Oxaloacetate
Fumarate
Citrate
Alpha-ketoglutarate
Which of the following is true of non-cyclic phosphorylation in photosynthesis?
The same electrons used by the oxygen evolving complex are not used for ADP phosphorylation.
ADP phosphorylated by Cfo/CF1 is transported from chloroplasts and not used by them, so there is no phosphorylation/dephosphorylation cycle
Activated electrons from NADP+ reduction are passed through Plastocyanin to reduce P700+
NADH donates electrons to reduce P680, causing phosphorylation of ADP
Molecular oxygen is evolved and NADP+ is reduced
Molecular oxygen is evolved and NADP+ is reduced
Which of the following is involved in Photophosphorylation and NOT Oxidative Phosphorylation
Cytochrome c
Cytochrome B6f
Coenzyme Q
Iron-Sulfur Centers (Clusters)
Copper Centers
Cytochrome B6f
You add carbamoyl phosphate with an isotopically-labelled nitrogen to the cell. Which of the following nucleotides will contain the nitrogen label?
None of these
CTP
ATP
GTP
CTP
The initial reaction in the REDUCTIVE phase (Stage 2) of the Calvin cycle is the reverse of a particular reaction in another pathway. What is the driving force for this reaction in the Calvin cycle?
This reaction uses Mg2+ and the elevated concentration of Mg2+ during the day helps to drive it forward
This reaction is favorable due to the high concentration of ATP made in the light reactions of photosynthesis.
This reaction is favorable due to the high concentration of NADPH made in the light reactions of photosynthesis.
In the direction it runs in the Calvin cycle, there is a large and negative LaTeX: \DeltaΔ
G’0 so the reaction is naturally favorable.
Submit
This reaction is favorable due to the high concentration of ATP made in the light reactions of photosynthesis.
In photosynthesis, absorption of light energy in chloroplast “light reactions” ultimately leads to:
absorption of O2 and release of CO2.
absorption of CO2 and release of O2.
hydrolysis of ATP and reduction of NADP+.
use of iron-sulfur proteins.
synthesis of ATP and oxidation of NADPH.
absorption of CO2 and release of O2.
How many reducing equivalents are transferred to molecular oxygen for the ten protons pumped out of the inner mitochondrial membrane by Complexes I through IV?
10
2
6
1
4
2
Identify which of the following is not present in chloroplasts but is present in mitochondria
Electron transport system
Porphyrin rings
DNA
Matrix
Iron-Sulfur centers (clusters)
Matrix
Onto which side of the mitochondrial membrane, or into which space, are protons actively pumped during electron transport?
Into the Cytoplasm
Into the Lumen
Into the Stroma
Into the Lamellae
Into the Intermembrane Space
Into the Intermembrane Space
There is a defect in Complex III of some mitochondria that prevents protons frombeing pumped to the intermembrane space by this complex. All other complexes apparently function normally. How many total protons are pumped during oxidative phosphorylation in these mutant mitochondria if the initial electrons come from NADH?
10
6
4
8
2
6
If ornithine labelled with 15N is added to cells actively metabolizing amino acids, which of the following molecules will be rapidly labelled with 15N?
Urea
Arginine
Citrulline
I only
III only
All of these
II and III only
II only
II and III only
The order of the key intermediates in cholesterol synthesis is:
activated isoprenes, mevalonate, squalene, lanosterol
mevalonate, activated isoprenes, squalene, lanosterol
activated isoprenes, mevalonate, lanosterol, squalene
mevalonate, activated isoprenes, lanosterol, squalene
mevalonate, squalene, activated isoprenes, lanosterol
mevalonate, activated isoprenes, squalene, lanosterol
What molecule is the ultimate electron donor in Photophosphorylation?
Chlorophyll
NADH
Water
Oxygen
Carbon Dioxide
Water
Why are Reaction Centers named as such? (That is, why are they called Reaction Centers?
They release an electron, meaning they participate in oxidation-reduction
They split water
They produce molecular oxygen
They produce carbon dioxide
They capture an exciton of light
They release an electron, meaning they participate in oxidation-reduction
Which of the following statements is TRUE about the following molecule:
In the mitochondria shuttle system, this molecule is generated in the matrix via oxidation of malate
This molecule is transported across the mitochondrial membrane by a shuttle system
This molecule is a direct carbon precursor to alanine, cysteine, and glycine
This molecule can be converted to pyruvate in a single enzymatic step
This molecule is the alpha-keto acid of glutamate
In the mitochondria shuttle system, this molecule is generated in the matrix via oxidation of malate
The final reaction in synthesizing dNTPs is catalyzed by ribonucleotide reductase. This enzyme will:
Reduce the 2’ OH on an NTP using 2 electrons
Oxidize the 3’ OH on an NTP releasing 2 electrons
Catalyze the hydrolysis of the 2’OH from an NTP.
Oxidize the 3’ OH on an NTP releasing 2 electrons
Reduce the 3’ OH on an NTP using 2 electrons
Reduce the 2’ OH on an NTP using 2 electrons
The synthesis of Cysteine from Serine requires ___ electrons to reduce sulfate to sulfide.
2
10
4
6
8
8
Refer to the following diagram of the plant photosystems. Which of the following statements is FALSE?
To synthesize a molecule of NADPH, photons must be absorbed at both P680 and P700
Electron transfer in PSI can contribute to ATP synthesis or NADPH synthesis
Photon absorption decreases the electron affinity of the reaction center
Cytochrome b6f has a higher standard reduction potential than ferridoxin
P700 has a higher electron affinity than P680.
P700 has a higher electron affinity than P680.
When the ΔG’° of the ATP synthesis reaction is measured on the surface of the ATP synthase enzyme, it is found to be close to zero. This is thought to be due to:
stabilization of ADP relative to ATP by enzyme binding.
a very low energy of activation.
enzyme-induced oxygen exchange.
None of the above
stabilization of ATP relative to ADP by enzyme binding.
stabilization of ATP relative to ADP by enzyme binding.
The product of the following reaction (indicated with ???) has which of the following uses?
it can be converted into another amino acid in a one-step reaction
All choices are correct.
It can be used to make Arginine
It can be directly fed into the Urea cycle
It can be incorporated in proteins
All choices are correct.
Which of the following is true regarding Ubiquinone?
It must accept two protons and 4 electrons to go from a fully reduced to a fully oxidized state.
None of the above statements is true regarding Ubiquinone
It is assigned to neither Complex II nor Complex III since its role is to function as a carrier between them
It can accept one electron to become a relatively stable radical
It contains one FAD and one iron-sulfur center
It can accept one electron to become a relatively stable radical
Which of the following statements is NOT true of the major regulatory point for cholesterol synthesis.
I. It is immediately after reactions which are shared with the formation of ketone bodies.
II. It is at a step where 2 NADPH molecules are consumed.
III. A coenzyme A molecule is released.
IV. It introduces a branch point in a linear molecule.
IV only
All of the choices are true.
II only
III only
I only
IV only
What vertebrate organ/tissue is responsible for production of large amounts of Ketone Bodies from ketogenic amino acids?
Muscle
Kidney
Liver
Brain
Intestine
Liver
Eukaryotic cells synthesize which of the following from CDP-diacylglycerol?
Sucrose
Starch
Glycerol
Phospholipids
Cholesterol
Phospholipids
Conversion of ornithine to citrulline is a step in the synthesis of:
tyrosine.
urea.
pyruvate.
aspartate.
carnitine.
urea.
