Elements of life

• 4 elements common to all life that make up 96% of the human body:

  • Oxygen
  • Carbon
  • Hydrogen
  • Nitrogen
• Our perception of solidity is influenced by how the electron clouds of different objects repel each other
• Macromolecule


  Complex biological molecules with carbon backbones
• Every biological molecule has a carbon backbone
• Carbon is such a good backbone for complex molecules because of its capacity to form 4 covalent bonds with as many as 4 other elements, and carbon-carbon bonds are unusually strong
• Methane

  CH4
• When a carbon atom is bonded to 4 other atoms, it will generally form a tetrahedral shape as the electron pairs repel each other
• Most macromolecules are not classified as hydrocarbons because they have other elements attached to the carbon
• Functional group 


  Chemical motifs in atoms that show consistent function
• A biomolecule's set of functional groups will affect many of its properties:

  • Solubility
  • Structure
  • Reactivity
• Methyl


  The only hydrophobic (nonpolar) functional group
• R


  Character used to represent the rest of a molecule in order to simplify it. Usually just leaves the functional group and this symbol
• Alcohols


  Hydroxyl class name
• Carboxylic acids


  Carboxyl class name
• Amines

  Amino class name
• Organic phosphates


  Phosphate class name
• Ketones


  Carbonyl class name
• Hydroxyl functional group

  
• Methyl functional group

  
• Carbonyl functional group

  
• Carboxyl functional group

  
• Amino functional group

  
• Phosphate functional group

  
• Sulfhydryl functional group

  
• Carbohydrates


  Macromolecule type that contains carbon, but never nitrogen or phosphorus
• Proteins


  Macromolecule type that contains carbon and nitrogen, but never phosphorus
• Nucleic acids


  Macromolecule type that contains carbon, nitrogen, and phosphorus
• Lipids


  Macromolecule type that always contains carbon, sometimes contains phosphorus, but never nitrogen