Lehninger-Principles-of-Biochemistry-(8th-
Edition)
Part-II:-Bioenergetics-and-Metabolism
Question-Bank-with-Answers-(200)
Original-practice-questions-for-study-and-revision.-Includes-schematic-diagrams-where-helpful.
,Contents
1.-Bioenergetics-fundamentals
2.-Glycolysis-and-fermentation
3.-Gluconeogenesis,-pentose-phosphate-pathway,-and-sugar-interconversions
4.-Citric-acid-cycle-and-anaplerotic-reactions
5.-Oxidative-phosphorylation-and-mitochondrial-energetics
6.-Glycogen-metabolism-and-hormonal-regulation
7.-Fatty-acid-catabolism-and-ketone-bodies
8.-Fatty-acid-and-lipid-biosynthesis
9.-Amino-acid-catabolism-and-the-urea-cycle
10.-Nucleotide-metabolism-and-integration-of-metabolism
,1.-Bioenergetics-fundamentals
Figure-1.-Activation-energy-and-catalysis-(free-energy-profile,-schematic).
Figure-2.-Coupling-an-endergonic-step-to-ATP-hydrolysis-(schematic).
Q1.-(Type:-MCQ)-Which-statement-best-defines-the-biochemical-standard-state-ΔG°′?-
A.-ΔG-when-reactants-are-at-1-M-and-pH-0
B.-ΔG-when-[H+]-is-fixed-at-10^-7-M-and-other-solutes-are-1-M
C.-ΔG-when-all-solutes-are-at-their-cellular-concentrations
D.-ΔG-when-temperature-is-0-°C
, Answer:-B
Explanation:-ΔG°′-uses-pH-7-(so-[H+]-=-10^-7-M)-while-other-solutes-are-1-M-at-a-defined-
temperature-and-pressure.
Q2.-(Type:-Short-answer)-Write-the-relationship-between-ΔG,-ΔG°′,-and-the-reaction-quotient-Q.
Answer:-ΔG-=-ΔG°′-+-RT-ln-Q
Explanation:-When-Q-differs-from-the-equilibrium-constant,-the-actual-driving-force-changes-
relative-to-standard-conditions.
Q3.-(Type:-Calculation)-At-298-K,-a-reaction-has-ΔG°′-=-+5.7-kJ/mol.-If-Q-=-0.01,-is-the-reaction-
spontaneous?-(Use-R-=-8.314-J/mol·K.)
Answer:-Yes;-ΔG-≈-+5.7-kJ/mol-+-(2.478-kJ/mol)·ln(0.01)-≈-+5.7-−-11.4-=-−5.7-kJ/mol.
Explanation:-Because-ln(0.01)-=-−4.605,-the-RT-ln-Q-term-can-outweigh-a-positive-ΔG°′.
Q4.-(Type:-True/False)-If-ΔG-is-negative,-the-reaction-must-proceed-rapidly.
Answer:-False
Explanation:-ΔG-indicates-thermodynamic-favorability,-not-rate;-kinetics-depends-on-activation-
energy-and-catalysts.
Q5.-(Type:-MCQ)-Which-pair-correctly-matches-a-cofactor-with-the-type-of-chemistry-it-commonly-
supports?
A.-NAD+—group-transfer
B.-Biotin—carboxyl-group-transfer
C.-FAD—phosphoryl-transfer
D.-TPP—methyl-transfer
Answer:-B
Explanation:-Biotin-carries-activated-CO2-for-carboxylation-reactions.
Q6.-(Type:-Short-answer)-What-is-the-biochemical-meaning-of-Keq-for-a-reaction?
Answer:-Keq-is-the-value-of-Q-at-equilibrium-where-ΔG-=-0.
Explanation:-At-equilibrium,-forward-and-reverse-rates-are-equal-and-there-is-no-net-change-in-
concentrations.
Q7.-(Type:-MCQ)-High-phosphoryl-transfer-potential-compounds-share-which-key-feature?
A.-They-are-all-nucleotides
B.-Their-hydrolysis-products-are-strongly-stabilized-(resonance,-hydration,-ionization)
C.-They-only-exist-in-mitochondria
D.-They-have-very-long-hydrocarbon-chains
Answer:-B
Explanation:-Stabilization-of-products-lowers-free-energy-after-hydrolysis,-making-transfer-favorable.
Q8.-(Type:-Short-answer)-Explain,-in-one-sentence,-how-cells-use-ATP-hydrolysis-to-drive-an-
endergonic-process.
Edition)
Part-II:-Bioenergetics-and-Metabolism
Question-Bank-with-Answers-(200)
Original-practice-questions-for-study-and-revision.-Includes-schematic-diagrams-where-helpful.
,Contents
1.-Bioenergetics-fundamentals
2.-Glycolysis-and-fermentation
3.-Gluconeogenesis,-pentose-phosphate-pathway,-and-sugar-interconversions
4.-Citric-acid-cycle-and-anaplerotic-reactions
5.-Oxidative-phosphorylation-and-mitochondrial-energetics
6.-Glycogen-metabolism-and-hormonal-regulation
7.-Fatty-acid-catabolism-and-ketone-bodies
8.-Fatty-acid-and-lipid-biosynthesis
9.-Amino-acid-catabolism-and-the-urea-cycle
10.-Nucleotide-metabolism-and-integration-of-metabolism
,1.-Bioenergetics-fundamentals
Figure-1.-Activation-energy-and-catalysis-(free-energy-profile,-schematic).
Figure-2.-Coupling-an-endergonic-step-to-ATP-hydrolysis-(schematic).
Q1.-(Type:-MCQ)-Which-statement-best-defines-the-biochemical-standard-state-ΔG°′?-
A.-ΔG-when-reactants-are-at-1-M-and-pH-0
B.-ΔG-when-[H+]-is-fixed-at-10^-7-M-and-other-solutes-are-1-M
C.-ΔG-when-all-solutes-are-at-their-cellular-concentrations
D.-ΔG-when-temperature-is-0-°C
, Answer:-B
Explanation:-ΔG°′-uses-pH-7-(so-[H+]-=-10^-7-M)-while-other-solutes-are-1-M-at-a-defined-
temperature-and-pressure.
Q2.-(Type:-Short-answer)-Write-the-relationship-between-ΔG,-ΔG°′,-and-the-reaction-quotient-Q.
Answer:-ΔG-=-ΔG°′-+-RT-ln-Q
Explanation:-When-Q-differs-from-the-equilibrium-constant,-the-actual-driving-force-changes-
relative-to-standard-conditions.
Q3.-(Type:-Calculation)-At-298-K,-a-reaction-has-ΔG°′-=-+5.7-kJ/mol.-If-Q-=-0.01,-is-the-reaction-
spontaneous?-(Use-R-=-8.314-J/mol·K.)
Answer:-Yes;-ΔG-≈-+5.7-kJ/mol-+-(2.478-kJ/mol)·ln(0.01)-≈-+5.7-−-11.4-=-−5.7-kJ/mol.
Explanation:-Because-ln(0.01)-=-−4.605,-the-RT-ln-Q-term-can-outweigh-a-positive-ΔG°′.
Q4.-(Type:-True/False)-If-ΔG-is-negative,-the-reaction-must-proceed-rapidly.
Answer:-False
Explanation:-ΔG-indicates-thermodynamic-favorability,-not-rate;-kinetics-depends-on-activation-
energy-and-catalysts.
Q5.-(Type:-MCQ)-Which-pair-correctly-matches-a-cofactor-with-the-type-of-chemistry-it-commonly-
supports?
A.-NAD+—group-transfer
B.-Biotin—carboxyl-group-transfer
C.-FAD—phosphoryl-transfer
D.-TPP—methyl-transfer
Answer:-B
Explanation:-Biotin-carries-activated-CO2-for-carboxylation-reactions.
Q6.-(Type:-Short-answer)-What-is-the-biochemical-meaning-of-Keq-for-a-reaction?
Answer:-Keq-is-the-value-of-Q-at-equilibrium-where-ΔG-=-0.
Explanation:-At-equilibrium,-forward-and-reverse-rates-are-equal-and-there-is-no-net-change-in-
concentrations.
Q7.-(Type:-MCQ)-High-phosphoryl-transfer-potential-compounds-share-which-key-feature?
A.-They-are-all-nucleotides
B.-Their-hydrolysis-products-are-strongly-stabilized-(resonance,-hydration,-ionization)
C.-They-only-exist-in-mitochondria
D.-They-have-very-long-hydrocarbon-chains
Answer:-B
Explanation:-Stabilization-of-products-lowers-free-energy-after-hydrolysis,-making-transfer-favorable.
Q8.-(Type:-Short-answer)-Explain,-in-one-sentence,-how-cells-use-ATP-hydrolysis-to-drive-an-
endergonic-process.
