20 Percent-35 Percent. Fats should account for 20-35% of an adult's calorie intake, but eating too much can increase the risk of heart disease.

Norephinephrine. Iproniazid, the first antidepressant drug, was originally developed as a cure for tuberculosis.

Amylase. Alpha-amylase is an enzyme found in saliva.

Five Pints. The blood in both arteries and veins is actually red despite veins appearing to be blue.

Idiopathic. The term Idiopathic comes from the Greek phrase meaning "a disease of its own kind".

20. A child will usually lose his or her first tooth by age seven.