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Author	Topic: My research about food.
mayday3003 04-14-2003 12:53 AM	All foods are made up of 7 main components: Carbohydrates (simple and complex) Proteins Fats Vitamins Minerals Fiber Water Carbohydrates provide your body with its basic fuel. Your body thinks about carbohydrates like a car engine thinks about gasoline. The simplest carbohydrate is glucose. Glucose, also called "blood sugar" and "dextrose," flows in the bloodstream so that it is available to every cell in your body. Your cells absorb glucose and convert it into energy to drive the cell. Specifically, a set of chemical reactions on glucose creates ATP (adenosine triphosphate), and a phosphate bond in ATP powers most of the machinery in any human cell. If you drink a solution of water and glucose, the glucose passes directly from your digestive system into the bloodstream. Glucose, fructose and galactose are monosaccharides and are the only carbohydrates that can be absorbed into the bloodstream through the intestinal lining. Lactose, sucrose and maltose are disaccharides (they contain two monosaccharides) and are easily converted to their monosaccharide bases by enzymes in the digestive tract. Monosaccharides and disaccharides are called simple carbohydrates. They are also sugars -- they all taste sweet. They all digest quickly and enter the bloodstream quickly. When you look at a "Nutrition Facts" label on a food package and see "Sugars" under the "Carbohydrates" section of the label, these simple sugars are what the label is talking about. There are also complex carbohydrates, commonly known as "starches." A complex carbohydrate is made up of chains of glucose molecules. Starches are the way plants store energy -- plants produce glucose and chain the glucose molecules together to form starch. Most grains (wheat, corn, oats, rice) and things like potatoes and plantains are high in starch. Your digestive system breaks a complex carbohydrate (starch) back down into its component glucose molecules so that the glucose can enter your bloodstream. It takes a lot longer to break down a starch, however. If you drink a can of soda full of sugar, glucose will enter the bloodstream at a rate of something like 30 calories per minute. A complex carbohydrate is digested more slowly, so glucose enters the bloodstream at a rate of only 2 calories per minute The word "carbohydrate" comes from the fact that glucose is made up of carbon and water. The chemical formula for glucose is: C6H12O6 What you can begin to see from this description is that there are actually lots of different things happening in your body around glucose. Because glucose is the essential energy source for your body, your body has many different mechanisms to ensure that the right level of glucose is flowing in the bloodstream. For example, your body stores glucose in your liver (as glycogen) and can also convert protein to glucose if necessary. Carbohydrates provide the energy that cells need to survive. A protein is any chain of amino acids. An amino acid is a small molecule that acts as the building block of any cell. Carbohydrates provide cells with energy, while amino acids provide cells with the building material they need to grow and maintain their structure. Your body is about 20-percent protein by weight. It is about 60-percent water. Most of the rest of your body is composed of minerals (for example, calcium in your bones). Amino acids are called "amino acids" because they all contain an amino group (NH2) and a carboxyl group (COOH), which is acidic. As far as your body is concerned, there are two different types of amino acids: essential and non-essential. Non-essential amino acids are amino acids that your body can create out of other chemicals found in your body. Essential amino acids cannot be created, and therefore the only way to get them is through food. Here are the different amino acids: Non-essential Alanine (synthesized from pyruvic acid) Arginine (synthesized from glutamic acid) Asparagine (synthesized from aspartic acid) Aspartic Acid (synthesized from oxaloacetic acid) Cysteine Glutamic Acid (synthesized from oxoglutaric acid) Glutamine (synthesized from glutamic acid) Glycine (synthesized from serine and threonine) Proline (synthesized from glutamic acid) Serine (synthesized from glucose) Tryosine (synthesized from phenylalanine) Essential Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine From this discussion you can see that your body cannot survive strictly on carbohydrates. You must have protein. Fats We all know about the common fats that different foods contain. Meat contains animal fat. Most breads and pastries contain vegetable oils, shortening or lard. Deep fried foods are cooked in heated oils. Fats are greasy and slick. You commonly hear about two kinds of fats: saturated and unsaturated. Saturated fats are normally solid at room temperature, while unsaturated fats are liquid at room temperature. Vegetable oils are the best examples of unsaturated fats, while lard and shortening (along with the animal fat you see in raw meat) are saturated fats. However, most fats contain a mixture. For example, above you see the label from a bottle of olive oil. It contains both saturated and unsaturated fats, but the saturated fats are dissolved in the unsaturated fats. To separate them, you can put olive oil in the refrigerator. The saturated fats will solidify and the unsaturated fats will remain liquid. You can see that the olive oil bottler even chose to further distinguish the unsaturated fats between polyunsaturated and monounsaturated. Unsaturated fats are currently thought to be more healthy than saturated fats, and monounsaturated fats (as found in olive oil and peanut oil) are thought to be healthier than polyunsaturated fats. Fats that you eat enter the digestive system and meet with an enzyme called lipase. Lipase breaks the fat into its parts: glycerol and fatty acids. These components are then reassembled into triglycerides for transport in the bloodstream. Muscle cells and fat (adipose) cells absorb the triglycerides either to store them or to burn them as fuel. You need to eat fat for several reasons: As we will see in the next section, certain vitamins are fat soluble. The only way to get these vitamins is to eat fat. In the same way that there are essential amino acids, there are essential fatty acids (for example, linoleic acid is used to build cell membranes). You must obtain these fatty acids from food you eat because your body has no way to make them. Fat turns out to be a good source of energy. Fat contains twice as many calories per gram as do carbohydrates or proteins. Your body can burn fat as fuel when necessary. Vitamins Vitamin A (fat soluble, retinol) comes from beta-carotene in plants; when you eat beta-carotene, an enzyme in the stomach turns it into Vitamin A. Vitamin B (water soluble, several specific vitamins in the complex) Vitamin B1: Thiamine Vitamin B2: Riboflavin Vitamin B3: Niacin Vitamin B6: Pyridoxine Vitamin B12: Cyanocobalamin Folic Acid Vitamin C (water soluble, ascorbic acid) Vitamin D (fat soluble, calciferol) Vitamin E (fat soluble, tocopherol) Vitamin K (fat soluble, menaquinone) Pantothenic acid (water soluble) Biotin (water soluble) In most cases, the lack of a vitamin causes severe problems. The following list shows diseases associated with the lack of different vitamins: Lack of Vitamin A: Night blindness, xerophthalmia Lack of Vitamin B1: Beriberi Lack of Vitamin B2: Problems with lips, tongue, skin, Lack of Vitamin B3: Pellagra Lack of Vitamin B12: Pernicious anemia Lack of Vitamin C: Scurvy Lack of Vitamin D: Rickets Lack of Vitamin E: Malabsorption of fats, anemia Lack of Vitamin K: Poor blood clotting, internal bleeding A diet of fresh, natural food usually provides all of the vitamins that you need. Processing tends to destroy vitamins, so many processed foods are "fortified" with man-made vitamins. Minerals Minerals are elements that our bodies must have in order to create specific molecules needed in the body. Here are some of the more common minerals our bodies need: Calcium - used by teeth, bones Chlorine Chromium Copper Fluorine - strengthens teeth Iodine - combines with tryosine to create the hormone thyroxine Iron - transports oxygen in red blood cells Magnesium Manganese Molybdenum Phosphorus Potassium - important ion in nerve cells Selenium Sodium Zinc We do need other minerals, but they are supplied in the molecule that uses them. For example, sulfur comes in via the amino acid methionine, and cobalt comes in as part of vitamin B12. Food provides these Water As mentioned above, your body is about 60-percent water. A person at rest loses about 40 ounces of water per day. Water leaves your body in the urine, in your breath when you exhale, by evaporation through your skin, etc. Obviously, if you are working and sweating hard then you can lose much more water. Because we are losing water all the time, we must replace it. We need to take in at least 40 ounces a day in the form of moist foods and liquids. In hot weather and when exercising, your body may need twice that amount. Many foods contain a surprising amount of water, especially fruits. Pure water and drinks provide the rest. Fibers Fiber is the broad name given to the things we eat that our bodies cannot digest. The three fibers we eat on a regular basis are: Cellulose Hemicellulose Pectin Hemicellulose is found in the hulls of different grains like wheat. Bran is hemicellulose. Cellulose is the structural component of plants. It gives a vegetable its familiar shape. Pectin is found most often in fruits, and is soluble in water but non-digestible. Pectin is normally called "water-soluble fiber" and forms a gel. When we eat fiber, it simply passes straight through, untouched by the digestive system. Cellulose is a complex carbohydrate. It is a chain of glucose molecules. Some animals and insects can digest cellulose. Both cows and termites have no problem with it because they have bacteria in their digestive systems secreting enzymes that break down cellulose into glucose. Human beings have neither the enzymes nor these beneficial bacteria, so cellulose is fiber for us.
Cheryl2002 04-14-2003 08:42 AM	Wow....thanks for this wealth of info....