chapter 6

• Biological macromolecules


  Large molecules necessary for life that are built from smaller organic molecules
• Major classes of biological macromolecules

  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids
• Biological macromolecules are organic, meaning they contain carbon
• Carbon


  The "foundation" element for molecules in living things, due to its bonding properties
• Carbon

  • Contains four electrons in its outer shell, allowing it to form four covalent bonds
  • Allows for the formation of long and branching chains of carbon compounds
  • Can bond with atoms of other elements like nitrogen, oxygen, and phosphorus
  • Can form ring structures
• The diversity of molecular forms of biological macromolecules accounts for their diversity of functions
• Carbohydrates


  Macromolecules that provide energy to the body, particularly through glucose
• Carbohydrate formula


  (CH2O)n, where n is the number of carbon atoms
• Carbohydrate subtypes


  • Monosaccharides
  • Disaccharides
  • Polysaccharides
• Monosaccharides

  Simple sugars, the most common of which is glucose
• Disaccharides

  Form when two monosaccharides undergo a dehydration reaction
• Common disaccharides


  • Lactose
  • Maltose
  • Sucrose
• Polysaccharides


  Long chains of monosaccharides linked by covalent bonds
• Examples of polysaccharides


  • Starch
  • Glycogen
  • Cellulose
  • Chitin
• Starch


  The stored form of sugars in plants, made up of amylose and amylopectin
• Glycogen


  The storage form of glucose in humans and other vertebrates
• Cellulose


  One of the most abundant natural biopolymers, a major component of plant cell walls
• Cellulose


  • Made up of glucose monomers linked in a specific way, giving it rigidity and high tensile strength
  • Cannot be broken down by human digestive enzymes, but can be digested by herbivores with the help of cellulase-producing bacteria
• Chitin


  A nitrogenous carbohydrate that makes up the exoskeleton of arthropods
• Carbohydrates serve different functions through differences in molecular structure
• Obesity is a worldwide health concern, and many diseases are becoming more prevalent due to obesity
• Registered dietitians


  Help plan food and nutrition programs for individuals in various settings, often working with patients to prevent and treat diseases
• To become a registered dietitian

  • Earn at least a bachelor's degree in a relevant field
  • Complete a supervised internship program
  • Pass a national exam
  • Take courses in nutrition, chemistry, biochemistry, biology, microbiology, and human physiology
• Camas bulbs have been an important food source for many Indigenous peoples of Vancouver Island and the western area of North America
• Inulin


  A type of carbohydrate used as dietary fiber, but not readily digested by humans
• Preparing camas bulbs for consumption

  1. Bake slowly in an underground firepit covered with specific leaves and soil

  2. Heat breaks down the long chains of inulin into digestible mono and di-saccharides
• While the blue camas is a food source, the white death camas is particularly toxic and deadly
• Carbohydrates


  Starch is the most common stored form in plants, some plants like camas create inulin
• Inulin


  • Used as dietary fibre, not readily digested by humans
  • Gives a bitter, gummy taste when raw
• Making camas bulbs digestible and tasty

  1. Bake slowly in underground firepit with leaves and soil

  2. Heat breaks down inulin into digestible sugars
• Properly baked camas bulbs taste like baked pear and cooked fig
• Blue camas is a food source, white death camas is toxic
• Lipids


  Diverse group of hydrophobic (water-fearing) compounds
• Functions of lipids


  • Store energy
  • Provide insulation
  • Building blocks of hormones
  • Important component of cell membranes
• Triglycerides

  Fat molecules composed of glycerol and fatty acids
• Fatty acids


  Long hydrocarbon chains with acidic carboxyl group, can be saturated or unsaturated
• Saturated fatty acids

  • Palmitic acid, stearic acid, butyric acid
• Unsaturated fatty acids

  • Oleic acid (monounsaturated), linoleic acid (polyunsaturated)
• Saturated fats are solid at room temperature, unsaturated fats are liquid
• Unsaturated fats help improve blood cholesterol, saturated fats contribute to plaque formation