With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Pi's fraction representation never ends.
text_B: Glutamate-1-semialdehyde is a molecule formed from by the reduction of tRNA bound glutamate , catalyzed by glutamyl-tRNA reductase .. tRNA. tRNA. glutamate. glutamate. glutamyl-tRNA reductase. glutamyl-tRNA reductase. It is isomerized by glutamate-1-semialdehyde 2,1-aminomutase to give aminolevulinic acid in the biosynthesis of porphyrins , including heme and chlorophyll .. glutamate. glutamate. glutamate-1-semialdehyde 2,1-aminomutase. glutamate-1-semialdehyde 2,1-aminomutase. aminolevulinic acid. aminolevulinic acid. porphyrins. porphyrins. heme. heme. chlorophyll. chlorophyll
not_related.