BioChem (mods)

• Biomolecules are any molecules that are produced by a living organism, including large macromolecules such as proteins, carbohydrates, lipids, and nucleic acids.
• Carbohydrates 'sugar' are the most common biomolecule.

  • Primary energy source for our body
  • Formula: CH2O
  • Building block/monomer: Monosaccharides
  • Elements: C-H-O
• Classifications of Carbohydrates

  1. Monosaccharides
  2. Disaccharides
  3. Polysaccharides
• Monosaccharides (simple sugars) - C6H2O6

  • basic subunit of carbs
  • have polar hydroxyl (-OH) groups
• A disaccharide will form if any two monosaccharides are joined
• Monosaccharides are Glucose (blood sugar), Fructose (fruit sugar), Galactose (Found in milk with lactose)
• Glucose + Glucose = Maltose (malt sugar)
• Glucose + Galactose = Lactose (Milk sugar)
• Glucose + Fructose = Sucrose (Table sugar)
• Disaccharides (double sugars) - C12H22O11
• Polysaccharides (complex sugars) - (C6H10O5)n, where n is the number of carbon atoms
• Polysaccharides are starch, glycogen, cellulose and chitin
• Starch

  • A polysaccharide made of alpha glucose molecules.
  • used for energy storage in plants
  • they provide a quick form of energy for the body
  • examples: potato, pasta, and rice
• Glycogen

  • used for energy storage in animals
  • when the body doesn't need glucose for energy it stores it in the liver
• Cellulose

  • found in plants, in cell walls and bark of trees
  • gives us fiber
• Chitin - forms the exoskeleton of certain insects and crustaceans
• Tests for Carbohydrates

  • Iodine test
  • Benedict's test
• Iodine test

  • used to determine the presence of starch in materials
  • a positive result is a change in color, ranging from violet to black
  • a negative result is yellow of the iodine solution
• Benedict's test

  • used for simple carbs
• Proteins

  • Body-building molecules which helps us grow
  • Transport molecules in and out of the cell
  • Controls the speed of chemical reactions
  • Building blocks: Amino acids
  • General formula: RCH(NH2)COOH, where R id a side chain, usually an amino acid
  • Elements: C-H-O-N
• Proteins are albumin(egg whites), hemoglobin (blood), fibrinogen(clotting)
• Tests for proteins

  1. Biuret test

  • used to determine the presence of a peptide bond in a substance
  • the test yields a negative result if the biuret reagent changes from blue to purple
• Nucleic acids

  • are not necessarily from food
  • biomolecular components of hereditary materials andare present in DNA and RNA
  • Building blocks: Nucleotides
  • Elements: C-H-O-N-P
• Lipids

  • are also energy-giving molecules, but they are more commonly referred as the stored-energy molecules.
  • they store more energy than carbs and proteins
  • building blocks: fatty acids
  • general formula: CH3(CH2)n COOH
  • elements: C-H-O
• Lipids provide mechanical protection for the internal organs of the body and serve as waterproof covering in some plants and animals
• Examples of lipids: Steroids, cholesterol, fats, oils, nuts, waxes
• Lipids are hydrophobic and don't dissolve in water
• Saturated fat - solids

  Unsaturated fat - liquid (oils)
• Tests for lipids - Ethanol emulsion
• Ethanol emulsion

  • ethanol is added to the sample
  • lipids are not present if the substance remains colorless and no emulsion is formed
  • lipids are present in the substance if a layer o cloudy white suspension forms above the solution
• Saturated fatty acids

  • are straight-chain hydrocarbons with single bonds between carbon atoms.
  • usually solid
  • produced by animals
  • Examples of animal fats are butter, lard, and tallow.
• Unsaturated fatty acids

  • contain one or more double bonds
  • usually liquid
  • produced by plants
  • Examples are vegetable oil, corn oil, and olive oil.
• Chemical reaction

  New substances are formed when chemical bonds are broken and atoms rearrange to create new chemical bonds
• Evidence of chemical reactions

  • Production of light
  • Evolution of gas
  • Temperature change
  • Change in intrinsic properties
  • Formation of a precipitate
• Phlogiston theory

  Theory that postulated a fire-like feature called Phlogiston within combustible bodies and released during combustion
• There are 20 amino acids found in human protein
• Isomers - compounds with the same molecular formulas but different structural formulas
• Excess glucose is stored in the liver as glycogen for later use
• Fructose - most sweetest naturally occurring sugar, found in fruits and honey
• Condensation reaction - is a reaction in which two molecules or parts of the same molecule combine to form disaccharides, losing one molecule of water.