The inoculating loop is used as a tool to inoculate microbes on plates. So it is necessary to flame the inoculating loop to destroy any kind of microorganisms that may contaminate ou interfer the culture medium. The fire, together with ethanol, helps to sterilize the loop, allowing it to inoculate a pure culture.
In glucose the hydroxyl group at carbon four is below the plane of the ring. In galactose the hydroxyl group at carbon four is above the plane of the ring.
