An enzyme synthesized in the laboratory is found to have little activity when compared to the enzyme ...

An enzyme synthesized in the laboratory is found to have little activity when compared to the enzyme extracted from cell culture. Both enzymes were examined and have identical amino acid composition.
 
  What is the best explanation for the lack of activity of the synthesized enzyme?
 
  A) The van der Waals radius was altered during laboratory synthesis.
  B) The synthetic enzyme was not made of amino acids.
  C) The ATP required for self-assembly was present in the cell extract but not in the laboratory synthesis.
  D) Denaturation of the synthesized enzyme was not complete.
  E) The synthesized enzyme was not folded correctly because molecular chaperones were not present.