The origin and chemistry of life

• Water


  It has several unusual properties that make it essential for life.
• Hydrolysis

  occurs when compounds are split into smaller pieces by the addition of a water molecule. 
• Polypeptide chains fold up into complex three-dimensional structures called proteins.
• Amino acids can be joined together through condensation reactions to form polypeptides.
• The amino acids join together to form polymers, which can be very long or short depending on their function.
• Amino acid sequences determine protein shape and function.
• Protein structure is determined by the sequence of amino acids along its chain.
• Carbohydrates 


  It functions as structural elements and as a source of chemical energy like glucose.
• Monosaccharides 


  single carbon chain
• Monosaccharides 


  Also called the "simple sugars"
• Disaccharides 


  two simple sugars bonded together
• Disaccharides 


  Also called "double sugars"
• Lactose


  Glucose + galactose
• Polysaccharides 


  many simple sugars bonded together in long chains
• Polysaccharides 


  Also called the "complex sugars"
• Glycogem


  important polymer for storing sugar in animals.
• Cellulose


  main structural carbohydrate in plants
• Lipids


  are fatty substances
• Water


  Act as solvent
• Condensation 


  Occurs when larger compounds are synthesized from smaller compounds
• Acid 


  A substance that liberates hydrogen ions in solution
• Base 


  a substance that liberates hydroxyl ions in solution
• pH

  Potential of hydrogen
• Neutral pH

  A solution with a pH of 7
• Base pH


  A solution with a pH of above 7
• Acid


  A solution with a pH of below 7
• Buffers


  Are molecules that prevent dramatic changes in the pH of fluids
• Neutral fats


  The major fuel of animals
• Triglycerides 


  Glycerol and there fatty acids
• Saturated 


  Fatty acids occurs when every carbon holds two hydrogen atoms
• Unsaturated 


  Fatty acids have two or more carbon atoms joined by double bonds
• Phospholipids 


  Important components of cells membrane
• Amphiphilic

  Compounds are polar and water-soluble on one and nonpolar on the other end
• Steroid 


  Complex alcohols with fatlike properties
• Proteins 


  Are large complex molecules composed of amino acids
• Peptide bonds


  Amino acids linked
• Dipeptide


  Two amino acids joined
• Polypeptide chain 


  Many amino acids
• Nucleic acids


  Complex molecules with particular sequences of nitrogenous bases that encode genetic information