Chemisrty of life

• Inorganic compounds


  Made of natural geo-physical processes in the environment, do not contain carbon (exceptions: carbon dioxide, carbide, carbonates, cyanide), mostly solid, have high melting point, cannot be synthesized by organisms
• Important groups of organic compounds in living organisms

  • Proteins
  • Lipids
  • Carbohydrates
  • Nucleic acids (DNA and RNA)
  • Enzymes
  • Vitamins
• Water


  Most important inorganic compound for living organisms, necessary for chemical reactions, main component of cells and body
• Functions of water


  • Solvent for inorganic and organic compounds
  • Medium for chemical reactions
  • Reagent during hydrolysis
  • Lubricant
  • Regulates body temperature
  • Gives shape and rigidity
• Mineral salts


  Inorganic, naturally found as salts in the external environment, needed and absorbed by living organisms
• Types of mineral salts

  • Micro elements (e.g. iron, iodine)
  • Macro elements (e.g. calcium, sodium, nitrogen, potassium, phosphorus)
• Carbohydrates


  Macronutrient, main food/energy source for most living organisms, energy stored as starch or glycogen, biomolecules composed of carbon, hydrogen and oxygen with hydrogen:oxygen ratio of 2:1
• Lipids


  Group of hydrophobic biomolecules that play important roles in living organisms, functions include long-term energy storage, protection, insulation, lubrication, and cell membrane component, structure includes carbon, hydrogen and oxygen with more hydrogen than oxygen
• Types of lipids

  • Triglycerides
  • Phospholipids
  • Steroids
  • Waxes
• Proteins


  Building blocks of life, structural components of cells and tissues, functions include DNA replication, structural support, storage, communication, digestion, transport
• Enzymes


  Act as biological catalysts, speed up rates of reactions, transform one form of energy into a more useful form, require cofactors, bind to specific substrates, not depleted or changed by the reaction
• How enzymes speed up chemical reactions

  1. Lower the activation energy

  2. Bind to substrate and hold it in a way that allows bond breaking and forming to occur easily
• Structure of enzymes


  Complex enzymes made of proteins and vitamins, simple enzymes made of only protein, have protein site, vitamin site, and non-protein parts
• How enzymes work


  1. Substrate binds to active site

  2. Enzyme becomes active

  3. Use lock and key model

  4. Product is set free when reaction is complete

  5. Enzyme can be used again
• Enzymes


  • Sensitive to temperature (optimal 37°C, higher temperatures denature them, lower temperatures slow the reaction rate)
  • Sensitive to pH (have an optimal pH)
• Enzyme concentration


  Increasing enzyme concentration increases the rate of reaction up to a certain point
• Substrate concentration


  Increasing substrate concentration increases the rate of reaction up to a certain point
• Nucleic acids


  Biomolecules responsible for control and transfer of genetic information, located in nucleus, mitochondria, cytoplasm, and chloroplasts
• Types of nucleic acids

  • DNA (double helix structure, replicates and repairs itself, controls cell metabolism)
  • RNA (single strand structure, synthesized by DNA, cannot replicate or repair itself)
• Vitamins


  Nutrients needed to remain healthy, complex organic compounds that act as cofactors in enzymes, lack causes deficiency diseases, can be water-soluble or fat-soluble
• Examples of vitamins

  • Vitamin A (good eyesight, healthy skin, fights infection)
  • Vitamin B (converts food to energy)
  • Vitamin C (healthy skin, gums, blood vessels, wound healing)
  • Vitamin D (strong bones and teeth)
  • Vitamin E (heart health, blood vessel cleaning, fights infection)
  • Vitamin K (blood clotting)
• Functions of water


  • Solvent for organic and inorganic compounds
  • Reagent during hydrolysis, breaks down macromolecules
  • Lubricant making swallowing and chewing easier
  • Gives shape and rigidity, cause internal pressure
  • Medium for chemical reactions