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Carbohydrates Carbohydrates • Carbohydrates are made up of CARBON, HYDROGEN and OXYGEN. • These atoms are usually in a ratio of 1:2:1.(Consider Glucose: C6H12O6) • Other Carbohydrates include: Galactose- a sugar in milk and yogurt Fructose- a sugar found in honey Why do living organisms need Carbohydrates? • They are the primary source of ENERGY. Sugars, the main components of complex carbohydrates, are broken down by cells to supply the energy a cells needs for all of the cell’s activities. The simplest carbohydrates are called MONOSACCHARIDES Monosaccharide means “simple sugar” Remember the prefix MONO means _____ And saccharide means __________!!!!! Some examples of monosaccharides are: Glucose, Galactose, and Fructose. Notice all three have the same molecular formula. C6H12O6. But they have different structures. This is called an ISOMER!! Monosaccharides Disaccharides A disaccharide is a combination of two monosaccharides. Example: When Glucose and Fructose combine Sucrose is formed. Sucrose is common TABLE SUGAR. Glucose + Fructose = SUCROSE Polysaccharides • The larger carbohydrates are called: polysaccharides. The prefix “poly” means many. So, if poly means many, saccharide means __________. So a polysaccharide means “many sugars”!!! Polysaccharides are polymers of sugar molecules linked together by COVALENT BONDS!! Types of Polysaccharides 1).Glycogen- a type of animal starch used to store excess sugar, which can release energy when needed. 2). Cellulose-a type of polysaccharide found in plants. Paper, cotton, and the outer shell of corn. (Remember from Botany, the cell walls of plants are made of Cellulose!!!) and think of corn….we can’t digest it very well…GROSS!! 3). Starch- chains of glucose units used by plants as food storage. Ex. carrots CHECK OUT THIS SITE!!!!! http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Carbohydrates.html Types of Carbohydrates • Monosaccharide-Example: • Disaccharide-Example: • Polysaccharide-Example: Why are carbohydrates important for me? • Alternative names: Starches; Simple sugars; Sugars; Complex carbohydrates; Diet carbohydrates; Simple carbohydrates • Definition Carbohydrates are one of the main dietary components. This category of foods includes sugars, starches, and fiber. • Function The primary function of carbohydrates is to provide energy for the body, especially the brain and the nervous system. Your liver breaks down carbohydrates into glucose (blood sugar), which is used for energy by the body. What foods do I eat that contain Carbs?? Complex carbohydrates, often referred to as "starchy" foods, include: • whole grain breads and cereals • starchy vegetables (carrots, potatoes) • legumes (beans) Simple carbohydrates that contain vitamins and minerals occur naturally in: • fruits • milk and milk products • vegetables Simple carbohydrates are also found in processed and refined sugars such as: These should be eaten sparingly!!!!! They have NO nutrietional value. • candy • table sugar • syrups (not including natural syrups such as maple) • regular carbonated beverages like cokes. What kind of carbs should I eat?? • • • • • • For most people, between 40% and 60% of total calories should come from carbohydrates, preferably from complex carbohydrates (starches) and naturally occurring sugars. Complex carbohydrates provide calories, vitamins, minerals, and fiber. Foods that are high in processed, refined simple sugars provide calories, but they have few nutritional benefits. It is wise to limit such sugars. To increase complex carbohydrates and healthy nutrients: Eat more fruits and vegetables. Eat more whole grains, rice, breads, and cereals. Eat more legumes (beans, lentils, and dried peas). What happens causes Diabetes? When Sugar Management Goes Awry: • Digestible carbohydrates are broken down in the intestine into their simplest form, sugar, which then enters the blood. As blood sugar levels rise, special cells in the pancreas churn out more and more insulin, a hormone that signals cells to absorb blood sugar for energy or storage. As cells sponge up blood sugar, its levels in the bloodstream fall back to a preset minimum. So do insulin levels. Sugar gone awry cont’d In some people, this cycle doesn't work properly. People with type 1 diabetes (once called insulin-dependent or juvenile diabetes) don't make enough insulin, so their cells can't absorb sugar. People with type 2 diabetes (once called non-insulin dependent or adult onset diabetes) usually start out with a different problem - their cells don't respond well to insulin's "open up for sugar" signal. This condition, known as insulin resistance, causes both blood sugar and insulin levels to stay high long after eating. Over time, the heavy demands made on the insulin-making cells wears them out, and insulin production slows, then stops.