Biomolecules

• Proteins are composed of one or more polypeptides
• Types of amino acids

  • polar
  • non-polar
  • acidic
  • basic
• Properties of the side chains on the amino acids

  Determine the overall shape of the protein and, therefore, its function
• In proteins, amino acids are joined by covalent bonds called peptide bonds
• Carboxyl groups and amino groups of the amino acids are shown in their charged form, which is how they exist in the cell
• A polypeptide can form a coil-like shape called an alpha helix or a folded fan-like shape called a beta pleated sheet
• A protein made of 50 amino acids could have 20^50 different possible sequences, greater than the number of atoms making up the Earth and everything on it
• A polymer composed of amino acid monomers is often called a polypeptide
• Amino acids

  • glycine
  • methionine
  • serine
  • aspartic acid
  • alanine
  • threonine
  • phenylalanine
  • cysteine
  • glutamic acid
  • valine
  • tyrosine
  • lysine
  • leucine
  • tryptophan
  • asparagine
  • arginine
  • isoleucine
  • proline
  • histidine
  • glutamine
• Cysteine is listed with the polar amino acids but is borderline between polar and non-polar
• Amino acids can occur in any sequence in a polypeptide, leading to an enormous variety of proteins
• Polypeptide


  A polymer composed of many amino acids linked together by covalent bonds
• Hydrogen bonding is possible between the C=O of one amino acid and the N-H of another amino acid in a polypeptide chain
• Proteins can be divided into four levels of organization: primary structure, secondary structure, tertiary structure, and quaternary structure
• Starch is a polysaccharide found in plants and serves as a storage form of glucose.
• Polysaccharides are complex carbohydrates made up of many monosaccharide units joined together.
• Triglycerides are a type of lipid that store energy and provide insulation and protection to organs.