Chemistry When it comes to nutrition, terms like carbohydrate, lipid, monosaccharide, protein and cholesterol can sound almost like a foreign language. With all the conflicting reports of what affects your body and what does harm, it is no wonder that people are so confused. Yet the importance of these substances is so vital that by understanding what these things are, as well as how they are used by our bodies can certainly benefit our health and overall well being.

Carbohydrates:

By definition, a carbohydrate is group of chemical compounds that exist when hydrogen and oxygen (H2O) are then combined with carbon (Ed., Encarta). Carbohydrates are the largest group of organic compounds found in nature (Encarta). Humans, animals, plants and bacteria all use carbohydrates, and the uses for them varies depending on the organism using them. Plants use them for structural uses - as in the cellulose and hemicellulose that are their main structural elements (Encarta). The cell coatings of the connective tissues in vertebrate animals have carbohydrates in them; both animals and plants use various forms of carbohydrates to store energy (Encarta). Chitin is a carbohydrate, and is the primary ingredient for the exoskeleton of invertebrate animals (Encarta).

Saccharides:

Monosaccharides are sugars, basically, with the same molecular formula, though each have different molecular structures (Kimball, Carbohydrates). There are three primary types of monosaccharides, and they are:

1- glucose (sugar used for energy for cellular respiration)

2- galactose (sugar found in milk, yogurt, dairy)

3- fructose (sugar found in honey)

Kimball, Carbohydrates).

Disaccharides are also sugars; they differ from the monosaccharides in that they are more complex sugars, while the former are commonly referred to as the simple sugars...

According to Kimball, the three most common disaccharides are:
1- sucrose (table sugar glucose + fructose)

2- lactose (milk sugar glucose + galactose)

3- maltose (product of starch digestion glucose + glucose)

Polysaccharides are not sugars, but one of three things - starches, glycogen or cellulose (Kimball, Carbohydrates). Potatoes, rice, breads, and corn are just a few of the sources of starches. When starches are digested, glucose and maltose are produced in varying mixtures (Kimball, Carbohydrates).

Glycogen is most often found in animals because this is where their excess glucose is polymerized and then stored (Kimball, Carbohydrates). Whenever energy is again in need, the glycogen is broken back down into its original form - glucose (Kimball, Carbohydrates).

Cellulose is the major component of the foundation of plants - wood is primarily cellulose, as is paper, and cotton (Kimball, Carbohydrates). Cellulose is a tough material, perfect for the cell walls of plants.

Lipds:

Lipids are fats, and are one of the vital nutrients of animal, and human nutrition (Haas, Fats, Lipids and Oils). Like carbohydrates, they are used primarily as stored energy though lipids are also used an insulation for the body (Haas). Lipids are divided into four subclasses:

1- Saturated fats - like animal fats (butter)

2- Monounsaturated - olive, and peanut oil

3- Polyunsaturated - corn oil, soy bean oil, sunflower oil, cottonseed oil, safflower oil

4- Trans Fats - partially hydrogenated fats with fewer double bonds

Haas).

Cholesterol:

Cholesterol is one of the more complex compounds found in the body, and is made up of alcohol, animal fat and oil (Haas). Cholesterol is related to an entire group of compounds called…