Carbohydrates

• Carbohydrates


  A polyhydroxy aldehyde or ketone; the polymers and derivatives of such compounds
• Saccharides


  Also called carbohydrates, from Greek word for something sweet
• Monosaccharide


  A single molecule; one carbohydrate/saccharide unit
• Oligosaccharide


  A combination of two to ten molecules or saccharide units
• Polysaccharide


  A polymer (chain of repeating units) with more than ten saccharide units
• Hydrolysis


  Chemical reaction/breaking of polysaccharide into smaller saccharides
• Glucose


  The body's primary fuel, the exclusive fuel of the brain, blood sugar, eaten directly from fruits or plants, formed by breaking down disaccharides or polysaccharides
• In the cell: oxidation of glucose


  glucose → CO2 + H2O + ENERGY (~4 Cal/g)
• All sugars are converted to glucose
• Fructose


  Found in fruits, plants, honey, and products sweetened by high fructose corn sweetener, an isomer of glucose with the same C6H12O6 formula but slightly different structures
• Sweetness of sugars (relative to sucrose)

  Fructose 173, Invert sugar (honey) 130, Sucrose 100, Glucose 74, Maltose 32, Lactose 16
• Disaccharides


  Table sugar (sucrose), milk sugar (lactose), malt sugar (maltose)
• Disaccharide formation


  The condensation reaction of two monosaccharides: 1 molecule of water is kicked out, glycosidic bond forms and the product is a disaccharide
• Sucrose


  Table sugar, also occurs in sugar beet and plant nectars, digested by hydrolysis: sucrose + water → glucose + fructose
• Lactose


  Found primarily in milk and milk products, also called "milk sugar": glucose + galactose
• Lactose intolerance


  Without enough lactase enzyme, lactose fermentation leads to CO2, H2 gases and lactic acid, causing gastric disorders and diarrhea
• Soy milk is a good substitute for lactose intolerance
• Simple sugars


  Polyhydroxy aldehyde or ketone, plenty of OH groups so very soluble in water and easily transported in the bloodstream
• Simple sugars


  • Candy, fruits, sweetened desserts
• Starch


  The main energy storage system of many plants, a polymer of 100 to 6000 glucose units with 1,4-glycosidic bonds
• Starch


  • Helical arrangement of α-linked glucose, no appreciable inter polymer H-bonding, more soluble in water than cellulose
• Amylose


  Has glucose units joined in a continuous chain, like beads in a string
• Amylopectin


  Has branched chain of glucose after every 25 units
• Cellulose


  Structural material of plants, i.e., plant fiber, composed of 1800 to 3000 units glucose units with 1,4-glycosidic bonds, O atom joining the glucose units is pointed upwards
• Fiber


  Not digested, passes through the digestive tract unabsorbed, increases the bulk of food without adding significantly to their caloric content, leads to feelings of fullness and satiety with lower caloric content, resulting in natural weight control, adds bulk to stools, prevents constipation and several digestive tract disorders, may lower rates of colon cancer
• Too much fiber may result in insufficient caloric intake, abdominal discomfort, limited nutrient absorption
• Foods rich in starches


  • Pasta, rice, beans, potatoes
• Foods rich in fiber

  • Hulls of wheat, rice, and corn, structural material of fruits and vegetables
• Glycogen


  Animal starch, composed of branched chain of glucose, arranged in granules in muscles and tissue
• Starch and cellulose can be distinguished by their reaction with iodine solution
• We should choose a diet with plenty of vegetables, fruits, and whole grain products, and use sugars only in moderation
• 1/2 cup of rice has 110 Calories versus pasta at 99, and potatoes at 68
• Diabetes mellitus


  Metabolic disorder with high blood sugar over prolonged period of time, can lead to damage to blood vessels, eyes, and nerves
• In the Philippines, 6.3% of adult population or 3,993,300 adults have diabetes mellitus
• You have completed the core learning material for carbohydrates, checkout the supplemental materials, record your learning experience, and participate in discussions