Biomolecules

• Biomolecules


  Complex organic molecules that form the basis of life and are required for growth, maintenance and survival of living organisms
• Main classes of biomolecules

  • Carbohydrates
  • Proteins
  • Lipids
  • Nucleic acids
• Macromolecules


  Large molecules composed of thousands of covalently connected atoms
• Six most common elements in biomolecules

  • Carbon
  • Hydrogen
  • Oxygen
  • Nitrogen
  • Phosphorus
  • Sulfur
• There are certain complex organic molecules which form the basis of life. These substances are part of the chemical composition of all living organisms. These substances are also required for their growth, maintenance and even for survival in extreme environment conditions. These substances are called biomolecules.
• Main classes of biomolecules

  • Carbohydrates
  • Proteins
  • Lipids
  • Nucleic acids
• Six most common elements in biomolecules

  • Carbon
  • Hydrogen
  • Nitrogen
  • Oxygen
  • Phosphorus
  • Sulfur
• Carbohydrates are comprised of the elements carbon (C), hydrogen (H), and oxygen (O)
• Monomer


  Single unit forming a long chain of molecules creating a repeated pattern
• Polymer


  Long molecule consisting of many similar building blocks, or a repeated pattern of various building blocks
• Examples of carbohydrates


  • Sugars found in milk (lactose)
  • Table sugar (sucrose)

  
• Carbohydrates


  Chemically defined as polyhydroxy aldehydes or ketones or compounds which produce them on hydrolysis
• Saccharides


  Collective term for carbohydrates (Greek: sakcharon = sugar)
• Types of carbohydrates by number of sugar units

  • Monosaccharides (1 sugar unit)
  • Oligosaccharides (2-10 sugar units)
  • Polysaccharides (more than 10 sugar units)

  
• Functions of carbohydrates


  • Excellent source of energy
  • Structural function (e.g. cellulose, starch, glycogen)
• Proteins


  Polymers of amino acids, arranged in the form of chain called polypeptide
• Levels of protein structure

  • Primary
  • Secondary
  • Tertiary
  • Quaternary
• Roles of proteins


  • Structural (e.g. hair, nails, muscles)
  • Dynamic (e.g. carriers, channels, enzymes)
• Lipids


  Wide variety of biomolecules including fats, oils, waxes and steroid hormones
• Properties of lipids


  • Do not dissolve in water; hydrophobic
• Nucleic acids


  Main information-carrying molecules of the cell, capable of being broken down to yield phosphoric acid, sugars, and a mixture of organic bases (purines and pyrimidines)
• Main classes of nucleic acids

  • DNA
  • RNA
• DNA


  Master blueprint for life and genetic material in all free-living organisms and most viruses
• RNA


  Responsible for creating proteins based on information given by DNA
• Nucleotide


  Building block of nucleic acids, consisting of a nitrogen-containing aromatic base, a pentose sugar, and a phosphate group
• Nitrogen-containing bases in nucleic acids

  • Adenine
  • Guanine
  • Cytosine
  • Thymine
  • Uracil
• Purines


  Adenine and Guanine
• Pyrimidines


  Cytosine, Thymine, and Uracil
• All macromolecules are polymers made up of monomers. Monomers are repetitive units that form a larger compound.
• Classes of biological molecules and the types of polymers they form and the monomers that act as subunits

  • Lipids - polymers called diglycerides, triglycerides; monomers are fatty acids

  Proteins - polymers are known as polypeptides; monomers are amino acids

  Nucleic Acids - polymers are DNA and RNA; monomers are nucleotides, which are in turn consist of a nitrogenous base, pentose sugar, and phosphate group

  Carbohydrates - polymers are polysaccharides and disaccharides; monomers are monosaccharides (simple sugars)

  
• Secondary structure involves hydrogen bonds between peptide groups that form alpha helices or beta pleated sheets.