CELLMOL LECT

• All living organisms require several compounds to continue to live
• Biomolecules


  Compounds required by all living organisms
• All biomolecules are organic, which means that they contain carbon
• Carbon


  Has 4 valence electrons, which means this element forms strong covalent bonds with many other elements
• Mas humahaba yung elements and they can form big biomolecules
• Classes of biomolecules


  • carbohydrates
  • lipids
  • proteins
  • nucleic acids

  
• Each of these classes have different structures and functions
• They are composed of carbon and they can form bonds that can make the structure bigger

  
• Four levels of biomolecules


  • Monomeric units
  • Macromolecules
  • Supramolecular complexes
  • The cell and its organelles

  
• Monomeric units


  Most basic and smallest, nucleotides, amino acids, sugars, form bonds to create bigger molecules

  
• Macromolecules


  DNA, protein, cellulose

  
• Supramolecular complexes


  Chromosome, plasma membrane, cell wall, where macromolecules are found, will eventually form the cell and its organelles
• Biomolecules


  Formed by joining many small units (monomeric units) together to form a long chain
• Dehydration synthesis


  Process where a water molecule is removed so that the small units will be joined together
• Hydrolysis


  Reverse process of dehydration synthesis, where water is ADDED, and a bigger molecule is broken down into smaller pieces

  
• Breaking down polymers


  Hydrolysis breaks a covalent bond by adding OH and H from a water molecule (H2O)

  
• Dehydration synthesis


  Removal of water to form a covalent bond

  
• Hydrolysis


  Addition of water to break a covalent bond

  
• Monomer


  Smallest functioning unit of a biomolecule
• Dimer


  Two monomers put together
• Polymer


  Several monomers put together
• Proteins are extremely important macromolecules in all organisms, occurring nearly everywhere in the cell
• Classes of proteins


  • Enzymes
  • Structural proteins
  • Motility proteins
  • Regulatory proteins
  • Transport proteins
  • Hormonal proteins
  • Receptor proteins
  • Defensive proteins
  • Storage proteins

  
• Only 20 kinds of amino acids are used in protein synthesis
• Some amino acids contain additional amino acids, usually the result of modification
• No two different proteins have the same amino acid sequence

  
• Amino acid


  Has a carboxyl group, amino group, and R group, its plane of symmetry can either be L or D

  
• Groups of amino acids based on hydrophobicity


  • Nonpolar Amino Acids (Hydrophobic)
  • Polar, Uncharged Amino Acids (Hydrophilic)
  • Polar, Charged Amino Acids (Hydrophilic)

  
• Polar amino acids tend to be found on the surface of proteins (can bind)

  
• Peptide bond


  Covalent C-N bond formed as the three atoms comprising H2O are removed
• Polypeptide


  Linear polymer formed by linking amino acids together
• 1. terminus


  End of polypeptide with the amino group
• 1. terminus


  End of polypeptide with the carboxyl group
• Peptide bonds form between the C and N terminus
• Protein synthesis


  Process of elongating a chain of amino acids
• Polypeptide


  Immediate product of amino acid polymerization, does not become a protein until it has assumed a unique, stable three-dimensional shape and is biologically active
• Monomeric proteins


  Consist of a single polypeptide
• Multimeric proteins


  Consist of two or more polypeptides
• Hemoglobin is a tetramer, consisting of two alpha subunits and two beta subunits

  
• Both covalent bonds and noncovalent interactions are needed for a protein to adopt its proper shape or conformation