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TLS Online TPP Program

#Question id: 563

Both water and glucose share an —OH that can serve as a substrate for a reaction with the terminal phosphate of ATP catalyzed by hexokinase.  Glucose, however, is about a million times more reactive as a substrate than water.  The best explanation is that:

#Section 2: General Biology

  1. glucose has more —OH groups per molecule than does water.

  2. the larger glucose binds better to the enzyme; it induces a conformational change in hexokinase that brings active-site amino acids into position for catalysis.

  3. the —OH group of water is attached to an inhibitory H atom, while the glucose —OH group is attached to C.

  4. water and the second substrate, ATP, compete for the active site resulting in a competitive inhibition of the enzyme.

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TLS Online TPP Program

#Question id: 403

#Section 2: General Biology

For the reaction A -> B, DG'° = –60 kJ/mol.  The reaction is started with 10 mmol of A; no B is initially present.  After 24 hours, analysis reveals the presence of 2 mmol of B, 8 mmol of A. Which is the most likely explanation?
TLS Online TPP Program

#Question id: 403

#Section 4: Fundamentals of Biological Engineering

For the reaction A -> B, DG'° = –60 kJ/mol.  The reaction is started with 10 mmol of A; no B is initially present.  After 24 hours, analysis reveals the presence of 2 mmol of B, 8 mmol of A. Which is the most likely explanation?
TLS Online TPP Program

#Question id: 404

#Section 4: Fundamentals of Biological Engineering

When a mixture of 3-phosphoglycerate and 2-phosphoglycerate is incubated at 25 °C with phosphoglycerate mutase until equilibrium is reached, the final mixture contains six times as much 2-phosphoglycerate as 3-phosphoglycerate.  Which one of the following statements is most nearly correct, when applied to the reaction as written?  (R = 8.315 J/mol·K; T = 298 K)  3-Phosphoglycerate -> 2-phosphoglycerate
TLS Online TPP Program

#Question id: 405

#Section 4: Fundamentals of Biological Engineering

When a mixture of glucose 6-phosphate and fructose 6-phosphate is incubated with the enzyme phosphohexose isomerase (which catalyzes the interconversion of these two compounds) until equilibrium is reached, the final mixture contains twice as much glucose 6-phosphate as fructose 6-phosphate.  Which one of the following statements is best applied to this reaction outlined below? (R = 8.315 J/mol·K; T = 298 K) Glucose 6-phosphate -> fructose 6-phosphate
TLS Online TPP Program

#Question id: 406

#Section 2: General Biology

Hydrolysis of 1 M glucose 6-phosphate catalyzed by glucose 6-phosphatase is 99% complete at equilibrium (i.e., only 1% of the substrate remains). Which of the following statements is most nearly correct? (R = 8.315 J/mol·K; T = 298 K)
TLS Online TPP Program

#Question id: 406

#Section 4: Fundamentals of Biological Engineering

Hydrolysis of 1 M glucose 6-phosphate catalyzed by glucose 6-phosphatase is 99% complete at equilibrium (i.e., only 1% of the substrate remains). Which of the following statements is most nearly correct? (R = 8.315 J/mol·K; T = 298 K)