Lactose

<p><b >Lactose</b>&nbsp;is a disaccharide&nbsp;<a href="http://en.wikipedia.org/wiki/Sugar" title="Sugar" >sugar</a>&nbsp;that is found most notably in&nbsp;<a href="http://en.wikipedia.org/wiki/Milk" title="Milk" >milk</a>&nbsp;and is formed from&nbsp;<a href="http://en.wikipedia.org/wiki/Galactose" title="Galactose" >galactose</a>and&nbsp;<a href="http://en.wikipedia.org/wiki/Glucose" title="Glucose" >glucose</a>. Lactose makes up around 2₈% of milk (by weight), although the amount varies among species and individuals. It is extracted from sweet or sour&nbsp;<a href="http://en.wikipedia.org/wiki/Whey" title="Whey" >whey</a>. The name comes from<i >lac</i>&nbsp;or&nbsp;<i >lactis</i>, the&nbsp;<a href="http://en.wikipedia.org/wiki/Latin" title="Latin" >Latin</a>&nbsp;word for milk, plus the -ose ending used to name sugars. It has a formula of C<sub >12</sub>H<sub >22</sub>O<sub >11</sub>.</p>