BioChem (mods)

Cards (76)

  • 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.