TLS Online TPP Program

#Question id: 3833


Regarding DNA replication, which, if any, of the following statements is incorrect?

#Unit 3. Fundamental Processes
  1. DNA replication is said to be semi-conservative because for each DNA helix only one strand serves as a template for new DNA synthesis.

  2. The two DNA strands of the parental DNA helix are unwound using a DNA helicase.

  3. The replication fork marks the point at which DNA is actively being replicated from a single DNA duplex to form new DNA strands.

  4. The synthesis of new DNA strands always proceeds in the 5’ → 3’ direction.

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TLS Online TPP Program

#Question id: 70

#Unit 1. Molecules and their Interaction Relevant to Biology

The dimensions of living cells are limited, on the lower end by the minimum number of biomolecules necessary for function, and on the upper end by the rate of diffusion of solutes such as oxygen. Except for highly elongated cells, they usually have lengths and diameters in the range of

TLS Online TPP Program

#Question id: 71

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is not the priority rule for R, S Configuration?

TLS Online TPP Program

#Question id: 72

#Unit 1. Molecules and their Interaction Relevant to Biology

For the reaction catalyzed by the enzyme hexokinase: Glucose + ATP → glucose 6-phosphate + ADP the equilibrium constant, Keq, is 7.8 × 102. In living E. coli cells, [ATP] = 5 mM, [ADP] = 0.5 mM, [glucose] = 2 mM, and [glucose 6-phosphate] = 1 mM. Which of the following conclusions made on the basis of the above calculations is incorrect?

TLS Online TPP Program

#Question id: 73

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the Variation of Reaction Spontaneity (Sign of ΔG) given in Column I with the Signs of ΔH and ΔS given in column II.

COLUMN I

COLUMN II

 

 

 

  ΔH

ΔS

ΔG = ΔH – TΔS

1.

+

a. The reaction is both enthalpically and entropically opposed. It is nonspontaneous (endergonic) at all temperatures.

2.

 −

− 

b. The reaction is enthalpically opposed (endothermic) but entropically favored. It is spontaneous only at temperatures above T = ΔH/ΔS.

3.

+

+

c. The reaction is enthalpically favored but entropically opposed. It is spontaneous only at temperatures below T = ΔH/ΔS.

4.

+

d. The reaction is both enthalpically favored (exothermic) and entropically favored. It is spontaneous (exergonic) at all temperatures.

TLS Online TPP Program

#Question id: 73

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the Variation of Reaction Spontaneity (Sign of ΔG) given in Column I with the Signs of ΔH and ΔS given in column II.

COLUMN I

COLUMN II

 

 

 

  ΔH

ΔS

ΔG = ΔH – TΔS

1.

+

a. The reaction is both enthalpically and entropically opposed. It is nonspontaneous (endergonic) at all temperatures.

2.

 −

− 

b. The reaction is enthalpically opposed (endothermic) but entropically favored. It is spontaneous only at temperatures above T = ΔH/ΔS.

3.

+

+

c. The reaction is enthalpically favored but entropically opposed. It is spontaneous only at temperatures below T = ΔH/ΔS.

4.

+

d. The reaction is both enthalpically favored (exothermic) and entropically favored. It is spontaneous (exergonic) at all temperatures.

TLS Online TPP Program

#Question id: 74

#Unit 1. Molecules and their Interaction Relevant to Biology

The enthalpy and entropy of the initial and final states of a reacting system are shown in the table. Calculate the change in free energy for the reaction when the temperature is 4°C.