10T2K© Biological Molecules

Thing 1: Organic macromolecules Organic molecules contain carbon. A macromolecule is a big molecule. There are many important biological macromolecules.

Thing 2: Polymers and monomers Many macromolecules are polymers. A polymer is a long chain of smaller molecules called monomers.

monomers polymer

Thing 3: Dehydration and hydrolysis The reaction that adds a monomer to a polymer is called a dehydration synthesis (aka condensation reaction) because a water molecule goes away. The reaction that removes a monomer from a polymer is called a hydrolysis reaction. Hydrolysis means splitting water. Water is broken to undo the polymer.

Dehydration synthesis/Condensation — OH — OH H— H2O H— — OH —

Hydrolysis H— — OH — H2O H— — OH H— — OH

Thing 4: Four kinds of macromolecule Polysaccharides Proteins Nucleic acids Lipids

Thing 5: Polysaccharides Polysaccharides are polymers of sugars. A single sugar is called a monosaccharide. Sugars and polysaccharides are carbohydrates. Polysaccharides have two main jobs: Storage polysaccharides store energy (starch, glycogen, etc.) Structural polysaccharides provide support and protection (cellulose, chitin, etc.)

Thing 6: Proteins Proteins are polymers of amino acids. Proteins do most of the things a cell does: Enzymes Movement and transport Structure Protection Food Lots more

Thing 7: Nucleic acids Nucleic acids are polymers of nucleotides. The two nucleic acids are DNA: genes are made of DNA. RNA: RNA has other genetic functions that we’ll discuss later.

Thing 8: Lipids—triglycerides Lipids are a diverse group of molecules, each with its own structure. What they have in common is that they all repel water. Fats and oils are called triglycerides. Triglycerides are made from three fatty acids attached to a molecule called glycerol. Triglycerides are used for energy storage and insulation.

Thing 9: Lipids—phospholipids Like fats and oils, phospholipids have glycerol and fatty acid chains, but… They have only two fatty acid chains. Instead of a third fatty acid chain, phospholipids have a phosphate group. Phospholipids are what cell membranes are made of.

Thing 10: Lipids—steroids Steroids look nothing like triglycerides or phospholipids. Steroids include… cholesterol (which is an important part of animal cell membranes) The sex hormones (cell signal molecules) testosterone and estrogen. The anabolic steroids that some athletes use.