biological molecules

• carbohydrates are the main source of energy for the body
• carbohydrates are made up of carbon, hydrogen, and oxygen
• monosaccharides 


  glucose, fructose, galactose
• disaccharides


  maltose, sucrose, lactose
• polysaccharides 


  starch, cellulose, glycogen, chitin
• how do we test for starch 


  add 2-3 drops of iodine solution

  positive result is blue-black

  negative result is orange-brown
• how do we test for reducing sugars 


  benedict's solution, heat for 5 minutes in water bath
• safety measures include: wearing goggles, wearing gloves, and using tongs
• lipids are the body's main source of energy and are used for energy storage and insulation
• lipids are made of carbon, hydrogen, and oxygen
• lipids are made up of three fatty acids and one glycerol
• how do we test for lipids


  add ethanol and shake well then add water

  positive result is cloudy
• proteins are used to make enzymes, hormones, hemoglobin, antibodies, and cytoplasm
• proteins are made up of carbon, hydrogen, oxygen, and nitrogen
• how do we test for protein 


  add biuret's solution

  positive result is purple
• DNA contains the instructions for growth and develpment of an organism.
• nucleotides are the individual units of DNA
• nucleotides contain the same phosphate and deoxyribose sugar but differ in the nitrogenous base
• the phosphate and sugar form the backbone of the DNA