TLS Online TPP Program

#Question id: 66


Which of the following statements regarding isomerism is incorrect regarding biomolecules?

#Section C (Domain-Specific Knowledge)
  1. Stereoisomers that are mirror images of each other are called enantiomers.

  2. A carbon atom with four different substituents is said to be asymmetric, and asymmetric carbons are called chiral centers.

  3. Pairs of stereoisomers that are not mirror images of each other are called diastereomers.

  4. An equimolar solution of the two enantiomers (a racemic mixture) rotates the plane of plane-polarized light in a particular direction.

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TLS Online TPP Program

#Question id: 73

#Section C (Domain-Specific Knowledge)

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

#Section C (Domain-Specific Knowledge)

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.

TLS Online TPP Program

#Question id: 75

#Section C (Domain-Specific Knowledge)

The experimental approach taken in current biological investigations presumes that ________.

TLS Online TPP Program

#Question id: 76

#Section C (Domain-Specific Knowledge)

Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.

TLS Online TPP Program

#Question id: 77

#Section C (Domain-Specific Knowledge)

Which of the pairs of molecular structures shown depict enantiomers (enantiomeric forms) of the same molecule?

TLS Online TPP Program

#Question id: 469

#Section C (Domain-Specific Knowledge)

The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation is accompanied by a net gain of: