science

• Biomolecules


  The most essential organic molecules involved in the maintenance and metabolic processes of living organisms
• Biomolecules are non-living molecules that are the actual foot soldiers of the battle of sustaining life
• Examples of biomolecules

  • Carbohydrates
  • Proteins
  • Nucleic Acids
  • Lipids
• Carbohydrates and lipids


  Generally made up of carbon, hydrogen and oxygen
• Carbohydrates


  The major source of energy for the body
• Types of carbohydrates

  • Monosaccharides
  • Disaccharides
  • Polysaccharides
• Monosaccharides


  The simplest sugar and the basic subunit of carbohydrate
• Monosaccharides


  Compounds that are white solids at room temperature because they have polar hydroxyl groups in their molecular structures, they are very soluble in water
• Common monosaccharides

  • Glucose (Dextrose)
  • Fructose
• Isomers


  Compounds with the same molecular formulas
• During digestion

  Carbohydrates are broken down into monosaccharides which are absorbed into blood and transported to the cells providing instant energy
• Fruits containing monosaccharide fructose

  • Grapes
  • Apples
  • Atis
• Fructose


  The sweetest naturally occurring sugar, sometimes used as a low calorie sweetener
• Glucose is the main constituent of starch, found in all plants and in the sap of trees, and is also found in glycogen produced in animal cells
• Disaccharides


  Carbohydrates formed from two monosaccharides
• Common disaccharides

  • Lactose
  • Maltose
  • Sucrose
• Sucrose


  Table sugar, the most common disaccharide that humans eat
• Formation and breakdown of sucrose

  1. Condensation reaction (two molecules combine, losing one water molecule)

  2. Hydrolysis reaction (bond between monosaccharides broken with addition of water molecule)
• Maltose


  Formed when two glucose molecules combine, with loss of water
• Lactose


  A disaccharide consisting of galactose and glucose, requires the enzyme lactase to be digested
• People with lactose intolerance cannot digest milk products because they do not produce the enzyme lactase
• Undigested lactose passes through the digestive system, where bacteria break it down producing gas and diarrhea
• Polysaccharides


  Large molecules made up of many smaller units joined together
• Examples of polysaccharides

  • Starch
  • Glycogen
  • Cellulose
• Starch


  The breakdown requires a water molecule to provide a hydrogen atom and a hydroxyl group to the site where the bond is broken, releasing glucose that can be absorbed and used as fuel by cells
• Starch is the storage form of carbohydrates in plants and the most important source of carbohydrates in human nutrition
• Starch

  Made up of two types of polysaccharides: Amylose (coiled/helical) and Amylopectin (branched)
• Glycogen


  A polysaccharide similar to starch, but with a higher degree of branching, made by animals to store excess glucose as fat