biological molecules

• Main categories of molecules in living organisms


  • Carbohydrates
  • Fats
  • Proteins
• Organic molecules


  Molecules that contain carbon
• Chemical elements present in carbohydrates, fats and proteins


  • Carbon
  • Hydrogen
  • Oxygen
  • Nitrogen
  • Sulfur
• Monomers


  Smaller molecules that larger molecules are made from
• Monosaccharide


  Simplest form of sugar molecule
• Disaccharide


  Two sugar molecules linked together
• Polysaccharide


  Many sugar molecules linked together
• Polysaccharides

  • Starch
  • Glycogen
  • Cellulose
• Fats/Lipids


  Large molecules made from smaller units of fatty acids and glycerol
• Oils


  Fats that are liquid at room temperature
• Proteins


  Molecules made of long chains of amino acids
• There are about 20 different amino acids
• Different combinations of amino acids result in different proteins
• Starch test


  1. Add iodine solution

  2. Observe color change to blue-black
• Reducing sugars test


  1. Add Benedict's solution

  2. Heat in water bath

  3. Observe color change to orange/brick red
• Protein test


  1. Add biuret solution

  2. Observe color change to violet/purple
• Fats/oils test


  1. Mix with ethanol

  2. Add to cold water

  3. Observe cloudy/milky emulsion
• Vitamin C test


  1. Add DCPIP solution

  2. Observe blue color disappearing
• DNA


  Molecule that contains instructions for growth and development of organisms
• DNA structure


  • Two strands wound in double helix
  • Contains chemical bases that pair up in specific ways (A-T, C-G)
• Biological molecules


  Molecules related to nutrients, which are substances needed for growth, repair and metabolism
• Main nutrients


  • Carbohydrates
  • Proteins
  • Lipids (fats and oils)
• Organic chemicals


  Chemicals that have carbon atoms combined with other atoms
• Metabolism


  All chemical reactions in cells, including respiration, which occurs in the mitochondria
• Covalent bond

  A bond formed when atoms share electrons to achieve a full outer shell
• Essential solvent


  Water, which is needed for metabolic reactions, producing plasma, and removing waste products like urea
• Composition of biological molecules

  • Carbohydrates: Carbon, hydrogen, oxygen
  • Lipids: Carbon, hydrogen, oxygen
  • Proteins: Carbon, hydrogen, oxygen, nitrogen, sulfur
• Monosaccharides


  Simple sugars, like glucose and fructose, that are the basic units of carbohydrates
• Disaccharides


  Two monosaccharides joined together
• Polysaccharides


  Many monosaccharides joined together, including starch, cellulose, and glycogen
• Carbohydrates


  • Provide energy
• Biochemical food tests


  1. Iodine solution: Tests for starch, turns blue-black

  2. Biuret test: Tests for proteins, turns purple

  3. Reducing sugar test: Tests for sugars, turns brick red to green-yellow-orange

  4. Emulsion test: Tests for lipids, turns cloudy
• Lipids


  Fats and oils, made from fatty acids and glycerol
• Lipids


  • Provide energy storage, regulate temperature, help seed germination
• Proteins


  Made up of amino acids, have an extra nitrogen molecule
• Proteins


  • Make new things, repair, grow, form antibodies and enzymes, make up structures like hair, nails, and haemoglobin
• DCPIP test


  Tests for vitamin C, solution turns colorless if present
• DNA


  Deoxyribonucleic acid, double helix structure with four bases: adenine, thymine, cytosine, guanine
• DNA base pairing


  Adenine pairs with thymine, cytosine pairs with guanine
• Chemical elements that make up carbohydrates, fats and proteins


  • Carbon
  • Hydrogen
  • Oxygen
  • Nitrogen
  • Sulfur
  • Phosphorus