BIOCHEM C785 FINAL COMPLETE TEST PAPER
WITH CORRECT ANSWERS
◉ Separate the redox reaction into its component half-reactions.
O2+2Mg⟶2MgOO2+2Mg⟶2MgO
Use the symbol e−e− for an electron.
Answer: oxidation half-reaction:
Mg⟶Mg2++2e−
reduction half-reaction:
O2+4e−⟶2O2−
◉ Label the compounds.
Answer: View
Ch 13 Q 3
◉ Label the compounds. 2
Answer: View
Ch 13 Q 4
,◉ Consider the reaction of pyruvate with NADH and the standard
reduction potentials, 𝐸′°, of pyruvate and NAD+.
Redox pair. E'°, V
pyruvate/lactate. -0.19
NAD+/NADH. -0.32
pyruvate+NADH↽−−⇀lactate+NAD+
Answer: The NAD+/NADH pair has the greater tendency to lose
electrons because the NAD+/NADH 𝐸′°NAD+/NADH E′° value is the
most negative.
◉ Select the redox pair that is the stronger oxidizing agent.
Answer: pyruvate/lactate
◉ Assuming that the concentrations of each reactant and product
are 1 M and that the reaction is performed at pH 7 and 25 °C,
determine the Δ𝐸′°ΔE′° for the reaction.
Based on the Δ𝐸′°ΔE′° value, select the direction in which the
reaction proceeds. A
nswer: Δ𝐸′°=0.13
,Δ𝐸′°=𝐸′°cathode−𝐸′°anode=(−0.19 V)−(−0.32 V)=0.13 V
The reaction proceeds to the right.
◉ The glycolysis pathway is shown. Place the enzymes used in each
of the ten labeled steps of the pathway. Be sure to scroll down
completely until pyruvate is formed.
Answer: Ch 14 Question 1
◉ The structures of five of the compounds of glycolysis are given.
Without using a reference, arrange them in order from the start of
glycolysis to the end of glycolysis.
Answer: Ch 14 Question 2
◉ In the first step of glycolysis, the given two reactions are coupled.
reaction 1: glucose+Pi⟶glucose-6-phosphate+H2O
Δ𝐺= +13.8 kJ/mol
reaction 2:ATP+H2O⟶ADP+Pi
Δ𝐺= −30.5 kJ/molreaction
, 1. Is reaction 2 spontaneous or nonspontaneous?
2. Complete the net chemical equation.
3. Calculate the overall ΔG for the coupled reaction.
4. Is the first step in glycolysis spontaneous (favorable)?
Answer: 1. spontaneous
2. ATP + glucose ⟶ glucose-6-phosphate + ADP
3. reaction 1Δ𝐺 = +13.8
reaction 2Δ𝐺 = −30.5
overall Δ𝐺 = −16.7 kJ/mol
4. yes
◉ Hexokinase catalyzes the first step of glycolysis, in which glucose
is phosphorylated to form glucose-6-phosphate.
Which of these statements are accurate?
Answer: - Hexokinase is a type of transferase that catalyzes the
transfer of a phosphoryl group from ATP to a hexose.
WITH CORRECT ANSWERS
◉ Separate the redox reaction into its component half-reactions.
O2+2Mg⟶2MgOO2+2Mg⟶2MgO
Use the symbol e−e− for an electron.
Answer: oxidation half-reaction:
Mg⟶Mg2++2e−
reduction half-reaction:
O2+4e−⟶2O2−
◉ Label the compounds.
Answer: View
Ch 13 Q 3
◉ Label the compounds. 2
Answer: View
Ch 13 Q 4
,◉ Consider the reaction of pyruvate with NADH and the standard
reduction potentials, 𝐸′°, of pyruvate and NAD+.
Redox pair. E'°, V
pyruvate/lactate. -0.19
NAD+/NADH. -0.32
pyruvate+NADH↽−−⇀lactate+NAD+
Answer: The NAD+/NADH pair has the greater tendency to lose
electrons because the NAD+/NADH 𝐸′°NAD+/NADH E′° value is the
most negative.
◉ Select the redox pair that is the stronger oxidizing agent.
Answer: pyruvate/lactate
◉ Assuming that the concentrations of each reactant and product
are 1 M and that the reaction is performed at pH 7 and 25 °C,
determine the Δ𝐸′°ΔE′° for the reaction.
Based on the Δ𝐸′°ΔE′° value, select the direction in which the
reaction proceeds. A
nswer: Δ𝐸′°=0.13
,Δ𝐸′°=𝐸′°cathode−𝐸′°anode=(−0.19 V)−(−0.32 V)=0.13 V
The reaction proceeds to the right.
◉ The glycolysis pathway is shown. Place the enzymes used in each
of the ten labeled steps of the pathway. Be sure to scroll down
completely until pyruvate is formed.
Answer: Ch 14 Question 1
◉ The structures of five of the compounds of glycolysis are given.
Without using a reference, arrange them in order from the start of
glycolysis to the end of glycolysis.
Answer: Ch 14 Question 2
◉ In the first step of glycolysis, the given two reactions are coupled.
reaction 1: glucose+Pi⟶glucose-6-phosphate+H2O
Δ𝐺= +13.8 kJ/mol
reaction 2:ATP+H2O⟶ADP+Pi
Δ𝐺= −30.5 kJ/molreaction
, 1. Is reaction 2 spontaneous or nonspontaneous?
2. Complete the net chemical equation.
3. Calculate the overall ΔG for the coupled reaction.
4. Is the first step in glycolysis spontaneous (favorable)?
Answer: 1. spontaneous
2. ATP + glucose ⟶ glucose-6-phosphate + ADP
3. reaction 1Δ𝐺 = +13.8
reaction 2Δ𝐺 = −30.5
overall Δ𝐺 = −16.7 kJ/mol
4. yes
◉ Hexokinase catalyzes the first step of glycolysis, in which glucose
is phosphorylated to form glucose-6-phosphate.
Which of these statements are accurate?
Answer: - Hexokinase is a type of transferase that catalyzes the
transfer of a phosphoryl group from ATP to a hexose.
