Biological molecules

• Important types of molecules in living matter

  • Proteins
  • Fats
  • Carbohydrates
• Molecules containing carbon, hydrogen and oxygen atoms

  • Proteins also contain nitrogen and sometimes phosphorus or sulfur
• Carbohydrates


  Made from simple sugar units, often glucose
• Uses of carbohydrates


  • Used as an energy source
  • Glycogen and starch make good storage molecules
  • Cellulose gives plant cells their strength
• Fats


  Made from fatty acids
• Proteins


  Made of chains of amino acids
• Cell membranes


  • Made up of proteins and fats
• Food tests


  Used to identify the different types of molecules
• DNA


  Another important biological molecule with a very distinctive shape, made up of nucleotides containing bases that always pair up in the same way: A with T and C with G
• Proteins


  Complex molecules that perform many functions in the body, including serving as enzymes, hormones, and structural components. Made up of amino acids.
• Amino acids


  The smaller units that proteins are made up of. They are linked together in chains to form proteins.
• Fats


  A diverse group of molecules that are insoluble in water. They play important roles in energy storage, insulation, and as components of cell membranes. Composed of fatty acids and glycerol.
• Fatty acids


  The building blocks of fats. They can be saturated, unsaturated, or trans fats.
• Glycerol


  A substance that combines with fatty acids to form fats.
• Carbohydrates


  Molecules that contain carbon, hydrogen, and oxygen atoms in a ratio of 1:2:1. A major source of energy for the body. Classified as monosaccharides, disaccharides, or polysaccharides.
• Monosaccharides


  Simple sugars. Examples include glucose and fructose.
• Disaccharides


  Two simple sugars linked together. Examples include sucrose (table sugar) and lactose (found in milk).
• Polysaccharides


  Many simple sugars linked together. Examples include starch (found in plants) and glycogen (found in animals).
• Enzymes


  Proteins that act as catalysts to speed up chemical reactions in the body.
• Hormones


  Proteins or steroids that are produced by glands and travel through the bloodstream to regulate the function of other organs and tissues.
• Antibodies


  Proteins produced by the immune system to defend the body against foreign substances, such as bacteria and viruses.
• Structural proteins


  Proteins that provide support and shape to cells and tissues. Examples include collagen and elastin.
• Saturated fatty acids


  Fatty acids in which all of the carbon atoms are bonded to as many hydrogen atoms as possible. They are solid at room temperature and can contribute to heart disease when consumed in excess.
• Unsaturated fatty acids


  Fatty acids in which some of the carbon atoms are bonded to each other, leaving fewer hydrogen atoms. They are liquid at room temperature and can help lower cholesterol levels when consumed in place of saturated fats.
• Monosaccharides


  Simple sugars. Examples include glucose, fructose, and galactose.
• Polysaccharides


  Many simple sugars linked together. Examples include starch (found in plants), glycogen (found in animals), and cellulose (found in the cell walls of plants).
• Trans fats


  Unsaturated fatty acids that have been chemically modified to be more solid at room temperature. They can increase the risk of heart disease and should be limited in the diet.
• Cell membranes


  Biological structures that surround cells and are primarily composed of proteins and fats
• Nucleic acids


  Molecules present in the nucleus of cells that are responsible for storing and transmitting genetic information; there are two types: DNA and RNA
• Fats


  Organic molecules that are insoluble in water, play important roles in energy storage, insulation, and as components of cell membranes, and are composed of fatty acids and glycerol.
• Nucleic acids


  Organic molecules that are also insoluble in water, play a crucial role in storing and transmitting genetic information in cells, and are composed of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base.