Question

What monosaccharides make up lactose?

Answer 1

The monosaccharides that make up lactose are galactose and glucose.

Explanation:

The structure of galactose, `"C"_6"H"_12"O"_6`, is

The structure of glucose, `"C"_6"H"_12"O"_6`, is

The `"OH"` on `"C-1"` of galactose can combine with the `"OH"` on `"C-4"` of glucose to form lactose

We could write the equation for the formation of lactose as

`underbrace("C"_6"H"_12"O"_6)_color(red)("galactose") + underbrace("C"_6"H"_12"O"_6)_color(red)("glucose") → underbrace("C"_12"H"_22"O"_11)_color(red)("lactose") + "H"_2"O"`