Chapter 4: Nutrition

• Disaccharides include sucrose (table sugar), lactose (milk sugar), maltose (malt sugar), trehalose (insect blood sugar), cellobiose (plant cell wall sugar), isomaltose (maltose with the two glucoses switched), gentiobiose (gentian root sugar), turanose (from sugar cane), melibiose (pea seed sugar), nigerose (from fungi), palatinose (corn syrup), and kojibiose (from rice fermentation).
• Monosaccharides include glucose (blood sugar), fructose (fruit sugar), galactose (milk sugar), ribose (ribonucleic acid component), deoxyribose (deoxyribonucleic acid component), glyceraldehyde (glycolysis intermediate), and xylulose (photosynthesis).
• The three major classes of carbohydrates are monosaccharides, disaccharides, and polysaccharides.
• The making of food calories

  1. Plants take 6 molecules of carbon dioxide from air

  2. Extract water from soil

  3. Use sun energy to rearrange molecules into glucose

  4. Oxygen is released into the air

  5. Glucose molecule stores the sun's energy in carbohydrate bonds
• When you need energy

  Your cells break down glucose and release the energy stored within the carbohydrate bonds
• Carbs are also found in lipids and protein (energy yielding nutrients)
• Small calorie (lower case c)

  Heat energy necessary to raise the temperature of one gram of water (1g of water 1 degree celsius)
• Using the small calorie to measure food would lead to large numbers on food labels (a single slice of toast would be 36,000 calories)
• Big Calorie (upper case C)


  The heat energy necessary to raise the temp of 1000 grams of water 1 degree celsius
• Kilocalorie


  1000 little calories = 1 Calorie = 1 Kilocalorie
• Energy is stored within the C-H bonds of glucose, proteins, and lipids
• Lipids


  Provide more energy than glucose or protein because they have a much greater abundance of carbohydragen bonds per gram
• Carbs and protein have the same number of carbohydragen bonds and they liberate the same amount of energy
• Bomb Calorimeter


  Can measure the energy content of food by burning the sample and measuring the heat released
• Carbohydrates and protein provide 4kcal per gram while lipids contain 9kcal per gram
• Simple Carbohydrates


  • Blood sugars
  • Fruit sugars
  • Milk sugar
  • Table sugars
• Alternative sweeteners


  Sugar alcohols and non-nutritive sweeteners that provide few or no calories
• Monosaccharides


  Have the same chemical formula (6 carbon, 12 hydrogen, 6 oxygen) but differ in the arrangement of the atoms, resulting in varying degrees of sweetness
• Monosaccharides


  • Glucose
  • Fructose
  • Galactose
• Glucose


  The dominant sugar in the body, the most important energy source for red blood cells and cells of the nervous system
• Fructose


  The sweetest tasting monosaccharide, found in fruit and honey
• Galactose


  Has a barely detectable sweetness, found in milk
• Disaccharides


  • Lactose (glucose + galactose)
  • Maltose (glucose + glucose)
  • Sucrose (glucose + fructose)
• Raw sugar, brown sugar and table sugar are all sucrose and do not contain any toxic substances
• Raw sugar and brown sugar are healthier than table sugar because they are less processed and contain more vitamins and minerals
• Food industries have replaced sucrose with high fructose corn syrup
• Microbes love simple sugars for energy
• Sugar Alcohols


  Could prevent dental cavities, not fully absorbed by the intestinal tract, provide 2 kcal/gram
• Sugar Alcohols


  • Sorbitol
  • Xylitol
  • Mannitol
• Glycogen


  The storage form of glucose in the body
• Starch


  The storage form of glucose in plants
• Dietary Fibers


  • Soluble fibers
  • Insoluble fibers
• Dietary fiber is the single most important complex carbohydrate for maintaining good health
• Amylopectin


  The branch type of starch that is quickly digested to glucose
• Amylose


  The linear thread of glucose molecules in starch that is slowly digested to glucose
• Most foods are a combination of amylopectin and amylose starches
• High starch potatoes


  Best for baking, mashing, and french frying because the starch granules swell and the plant cells separate when cooked
• Low starch waxy potatoes


  Good for salads because they hold their shape better when boiled
• The carbohydrate content plummets in sprouted mung beans and soy because the plant embryo burns the starch for energy during germination
• Glycogen


  The storage form of glucose in animal cells, stored in the liver and muscle cells