For example, some ingredients may be safe in products such as cleansers that we wash off the skin immediately, but not in products that we leave on the skin for hours. Similarly, ingredients that are safe for use on the hair or nails may be unsafe when used on the skin or near the eyes.
Carbohydrates are the main energy source for the brain. Without carbohydrates, the body could not function properly. Sources include fruits, breads and grains, starchy vegetables and sugars. Make at least half of the grains you consume whole grains.
(See Figure 1 for a simple structural formula and a space filled model of ATP.) As far as known, all organisms from the simplest bacteria to humans use ATP as their primary energy currency. The energy level it carries is just the right amount for most biological reactions. Nutrients contain energy in low-energy covalent bonds which are not very useful to do most of kinds of work in the cells. These low energy bonds must be translated to high energy bonds, and this is a role of ATP.