Intro to biological macromolecules

• Atoms form chemical bonds to be in their lowest-energy form: when they have a full shell of valence electrons
• Cations


  Positive ions formed by losing electrons
• Anions


  Negative ions formed by gaining electrons
• Crystal


  Many atoms/molecules arranged in a repeating, predictable 3D pattern
• Covalent bonds are more common than ionic bonds in the molecules of living organisms
• London dispersion forces


  Weak intermolecular bonds that can happen between any two elements when the randomness of an atom's electrons gives one side a partial charge, which goes on to affect the other atoms around it, creating weak bonds
• Van der Waals forces


  Weak bonds between molecules caused by a temporary charge by random positioning of electrons, otherwise known as London dispersion forces
• Strong covalent bonds hold together the nucleotides in a strand of DNA so that it stays together
• Weak hydrogen bonds keep the strands of DNA in a double helix, but can be easily unzipped by helicase
• The main four types of large biomolecules are:

  • carbohydrates
  • proteins
  • nucleic acids
  • lipids
• Polymer


  Long chains made up of smaller repeating molecular subunits
• Monomer


  Small molecular subunit that makes up polymers
• Lipids


  The only major macromolecule that doesn't tend to form polymers
• Dehydration synthesis


  When two macromolecules attach themselves to each other by forming a covalent bond, then each releasing atoms that end up forming a water molecule, where this process gets its name
• Dehydration synthesis

  
• Many different polymers with super different functions can be produced from the same basic monomers
• Hydrolysis


  The reverse of a dehydration synthesis reaction
• Hydrolysis


  When a polymer breaks into individual monomers again by adding water, which breaks the covalent bonds between them, adding a H ion to one branch and an OH ion to the other
• hydrolysis reaction