Jack and Jill (nursery rhyme) and brown paper were a home cure used as a method to draw out bruises on the body. Jack is the most common name used in English-language nursery rhymes and represented an archetypal Everyman hero by the 18th century, while Jill or Gill had come to mean a young girl or a sweetheart by the end of the Middle Ages. However, the woodcut that accompanied the first recorded version of the rhyme showed two boys (not a boy and a girl) and used the spelling Gill not Jill. The true origin of the rhyme is unknown, but there are several
S-ribosylhomocysteine lyase S-ribosylhomocysteine lyase In enzymology, a S-ribosylhomocysteine lyase () is an enzyme that catalyzes the chemical reaction Hence, this enzyme has one substrate, S-(5-deoxy-D-ribos-5-yl)-L-homocysteine, and two products, L-homocysteine and (4S)-4,5-dihydroxypentan-2,3-dione. This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is S-(5-deoxy-D-ribos-5-yl)-L-homocysteine L-homocysteine-lyase [(4S)-4,5-dihydroxypentan-2,3-dione-forming]. Other names in common use include S-ribosylhomocysteinase, and LuxS. This enzyme participates in methionine metabolism. Furthermore, LuxS is involved in the synthesis of autoinducer AI-2 (autoinducer-2), which plays a role in quorum sensing in a certain number of bacterial species. LuxS converts S-ribosylhomocysteine to homocysteine and