The lemon is a small evergreen tree (Citrus limon) originally native to Asia, and is also the name of the tree's oval yellow fruit. The fruit is used for culinary and nonculinary purposes throughout the world – primarily for its juice, though the pulp and rind (zest) are also used, mainly in cooking and baking. Lemon juice is about 5% (approximately 0.3 mole per litre) citric acid, which gives lemons a sour taste, and a pH of 2 to 3. This makes lemon juice an inexpensive, readily available acid for use in educational science experiments. Because of the sour flavor, many lemon-flavored drinks and candies are available, including lemonade.
Full of useful antioxidants, and that is the saving grace of the lemon. Otherwise, these suckers are VERY sour, and you'll definitely be getting those sour lips if you eat one on its own. Sugar can be a big help in defusing the sour flavor, but you're better off just adding lemon juice or lemons to larger meals as light flavoring.