-Carbohydrate foods provide practical energy sources b/c of their availability, low cost, & storage capacity
-provide both quick & extended energy for the body
To transform solar energy into carbs; the stored fuel form of plants
Sunlight = Energy
-Plants containing chlorophyll are able to manufacture carbohydrate by combining CO2 and water
-Chemical name for a sugar molecule
Saccarideis used as a carbohydrate classname, the word comes from the Latin word meaning sugar
Sugars with a simple structure of one or two single sugar units
Large complex molecules of carbohydrates composed of many sugar units.
Carbohydrates are composed of:
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
Building blocks for all carbs that require no furthur digestion.
-basic single sugar in body metabolism.
- - form of sugar circulating in the blood & primary fuel for cells
- Fructose: mainly found in fruits; sweetest of simple sugars. (ex: honey)
- Galactose: comes from the digestion of milk sugar or lactose
Ex: Corn Syrup
- complex carbs composed of many single-sugar units.Starch: most significant polysaccharide in the diet. Found in grains, legumes, & other veggies. Breaks down more slowly & supply energy over a long period
- Whole grain – Food products such as flour, bread,and cereals that still retain its outer bran layer andthe inner germ endosperm and nutrients (see page 19)
- Glycogen: Carb formed within the body's tissues & crucial to metabolism & energy balance. Found in liver & muscles.
- Dietary Fiber: no direct energy value but is important to dietary assets.
- Cellulose: helps move food mass along, stimulates normal muscle action.
- Lignin: binds cellulose fibers, gives strength to plants
- Noncellulose polysaccharide: slows food mass from the stomach
- Simple double sugars composed of two single-sugar units linked.
- Sucrose: common table sugar; form of powdered/brown sugar; Glucose + Fructose
- Lactose: sugar in milk; formed in mammary glands; Glucose + Galactose
- Maltose: derived in the body from digestive breakdown of starch; used as a sweetener in processed foods; Glucose + Glucose
-provide practical energy sources because of their availability, low cost, & storage capacity
-structures vary from simple to complex, so they can provide both quick & extended energy for the body.
-Dietary fiber, and indigestible carbohydrate, serves separately as a body regulatory agent
(Relation to Energy)
- - Energy is necessary for life. Need fuel for energy. Basic fuel source.
- - Sugars and starches are main source of energy
Nutritive sweeteners that provide 2 – 3 Kcal per gram, sorbitol, mannitol and xylitol
Sugar alcohol formed in mammals fromglucose and converted to fructose
Specific proteins produced in cells that digestor change specific nutrients in specific chemical reactions with out being changed themselves in the process
Cells that are located on the microvilli within the lining of the intestinal tract
- Sugar alcohols andalternative sweeteners are often used assugar replacement.
- - Nutritive sweeteners- Sorbitol, mannitolxylitol are the alcohol form of sucrose
- - Nonnutritive sweeteners- aspartame andsaccharinOther
Functions of Carbohydrates
- -Basic fuel supply- 4 Kcal/g
- Fuel for the body
- Burn in the body to meet energy needs
- -Special tissue functions
- Liver – Glycogen reserves in the liver and muscle – createreserves to protect cells form depressed metabolic function andresulting in injury
- -Protein and fat- Regulates protein and fat production-Proteins are broken down for source of energy if nocarbohydrates – Ketones are the by product - The Ketones are strong acids and creates acidosis. This upsets the acid base balance
- Heart – Fatty acids are the preferred fuel for the heart muscle. Glycogen is used in emergency situationsmay cause cardiac disorder and angina
- Central nervous system
Food Sources for Carbs
- -Starches– fundamental complex carbohydrate foods for slowly available glucose
- -Sugars - not the villain in the story of health
- -Too much sugar
- 1. Some starch is broken down by salivaryamylase to maltose.
- 2. Salivary amylase in inactivated by strong acid
- 3. Enzymes (amylase) from pancreas breakdown starch into maltose
- 4. Enzymes in wall of small intestine breakdown disaccharides sucrose, lactose and maltose into monosaccharide glucose, fructose, and galactose
- 5. Absorption of glucose, fructose andgalactose into blood stream to be takento the liver
- 6. Some soluble fiber is fermented intovarious acid and gases by bacteria in the large intestines
- 7. Insoluble fiber is excreted in feces, butlittle other dietary carbohydrate ispresent.
Digestion of Carbs
- -mechanical and chemical
- -Mechanical is the process of chewing the food (mastication)
- -Pancreatic secretions are pancreatic amylasewhich breaks down disaccharides andmonosaccharides
- -Mouth– mixes with saliva and salivaryamylase (ptyalin) secreted by the parotidgland, located under ear and in back of jaw
- -Stomach- peristalsis wave like action of muscles fibers of the stomach wall
- Hydrochloric acid in the stomach stops the
- secretions of the parotid glands
- Small intestine – carbohydrate digestion iscomplete in the small intestines by enzymes secreted by the pancreas
- Intestinal secretions- sucrase, lactase, andmaltase they act in their respective disaccharideto create glucose, galactose and fructose
Ethnicity & Lactose Intolerance
-African American and Native American suffer from lactose intolerance more than Caucasian.
-100% of Native Americans endure some form of lactose intolerance
95% of African American suffer with some form of lactose intolerance
12% Caucasian suffer from lactose intolerance