SCIENCE 4TH QTR

• Biomolecules


  Any molecules that are produced by a living organism
• Molecules


  Two or more atoms join together chemically
• Carbohydrates

  The main source of energy of the body
• Carbohydrates

  • Composed of carbon, hydrogen and oxygen atoms in a 1:2:1 ratio
  • Most common/abundant biomolecule on Earth
  • Also known as saccharides
• Saccharides

  Derived from the Greek word "sakcharon" meaning "sugar" and the Latin word "saccharum" meaning "sugar"
• Carbohydrates

  Can be described as simple or complex depending on the length or number of units they contain
• Classifications of carbohydrates

  • Monosaccharides
  • Disaccharides
  • Polysaccharides
• Monosaccharides

  Simplest form of carbohydrates, building blocks of complex carbohydrates
• Monosaccharides

  • Have the same chemical formula C6H12O6 but different structural formulas
  • Smallest carbohydrate molecules
  • Also known as simple sugars
• Monosaccharides

  • Glucose
  • Fructose
  • Galactose
• Glucose

  Most important simple sugar, primary form of sugar stored in the body as a source of energy
• Fructose

  Also called levulose or fruit sugar, the primary carbohydrate derived from fruits and honey
• Galactose

  Found in dairy products, fruits and vegetables, must be transformed into glucose by the liver before it can be utilized by the body for energy
• Disaccharides

  Consist of two monosaccharide units connected together by a glycosidic linkage
• Glycosidic linkage

  A type of covalent bond that links a carbohydrate molecule to another
• Disaccharides

  • Sucrose
  • Maltose
  • Lactose
• Sucrose

  Most well-known disaccharide, a combination of glucose and fructose, commonly known as table sugar
• Maltose

  Made up of the combination of two glucose units, an intermediate in the intestinal digestion of glycogen and starch
• Lactose

  The principal carbohydrate in milk, made up of galactose and glucose
• Lactase

  A digestive enzyme that breaks down lactose into its simple sugar units
• Lactose intolerance

  A low level of lactase in the digestive system does not effectively hydrolyze milk, causing gastric distress and diarrhea
• Relative sweetness of simple carbohydrates

  • Fructose: 173
  • Glucose: 74
  • Maltose: 31
  • Lactose: 16
• Polysaccharides

  Large polymers of sugar, composed of many monosaccharides linked together through glycosidic linkages
• Examples of polysaccharides

  • Starch
  • Glycogen
  • Cellulose
  • Chitin
• Storage polysaccharides

  Serve as reserve food
• Structural polysaccharides

  Make up the cell walls of plants
• Starch

  A soft, white and tasteless powder that is soluble in warm water but insoluble in cold water, consists of long chains of glucose units
• Cellulose


  A linear polymer of glucose, the principal structural component of plant cell walls, an indigestible carbohydrate that forms dietary fiber
• Cellulase


  An enzyme used to breakdown cellulose, present in the digestive tracts of animals like cows, sheep, goats and horses
• Glycogen


  Also known as animal starch, a polysaccharide made of glucose units with a more complex branched structure, stored in the liver and muscles as a readily available glucose reservoir
• Chitin


  The major constituent of the exoskeleton of fungi and arthropods, consists of a long chain of N-acetylglucosamine - a derivative of glucose
• Summary of carbohydrate classifications

  • Monosaccharides: Glucose, Fructose, Galactose
  • Disaccharides: Sucrose, Maltose, Lactose
  • Polysaccharides: Starch, Cellulose, Glycogen, Chitin
• Compound


  a mixture of 2 or more elements.
• Element

  is a pure substance that has 1 phase
• Mixture


  can be homogenous (1 phase) or heterogenous (2 or more phases)
• Organic Compounds


  Carbon-based
• Carbon dating


  the process of determining the age of a fossil.
• Carbon - 14 print


  isotope of carbon
• Atom


  building block of matter
• Elementary Particles


  building block of atom