Chemical substance In organic chemistry, there can be more than one chemical compound with the same composition and molecular weight. Generally, these are called isomers. Isomers usually have substantially different chemical properties, and often may be isolated without spontaneously interconverting. A common example is glucose vs. fructose. The former is an aldehyde, the latter is a ketone. Their interconversion requires either enzymatic or acid-base catalysis. However, tautomers are an exception: the isomerization occurs spontaneously in ordinary conditions, such that a pure substance cannot be isolated into its tautomers, even if these can be identified spectroscopically or even isolated in special conditions. A
Jeff Lewis (writer) Strikes Back" - Nominee<br> 1983: "Hill Street Blues" - David Milch, Jeffrey Lewis, Michael Wagner for "Gung Ho!" - Nominee<br> "'1984: "Hill Street Blues" - Teleplay by Jeffrey Lewis, Michael Wagner, Karen Hall, Mark Frost Story by Steven Bochco, Jeffrey Lewis, David Milch for "Grace Under Pressure"<br> 1984: "Hill Street Blues" - Teleplay by Jeffrey Lewis, Michael Wagner, David Milch, Mark Frost Story by Steven Bochco, Jeffrey Lewis, David Milch for "Parting Is Such Sweep Sorrow" - Nominee<br> 1985: "Hill Street Blues" - Teleplay by David Milch & Roger Director Story by Steven Bochco, Jeffrey Lewis, David Milch for "Watt