Nucleic Acids

• isolation of rna from yeast

  1. mix white sand and yeast and grind them up in a mortar
  2. add 15ml of freshly prepared 0.2% NaOH and puro the mixture into a 250 ml beaker and adjust the volume to 50ml by adding more 0.2% NaOH solution
  3. cover with a watch glass to avoid evaporation and heat the beaker in a water bath at 90 celcius for 30 mins.
  4. filter 3 times thru cheesecloth
• nucleoprotein

  • to a 1ml of filtrate, add 1 ml of 10% NaOH solution and 5 to 10 drops of 1% CuSO4 solution.
• add 20ml of 10% h2so4 to the remaining filtrate in a beaker and boil gently for a few mins.

  inorganic phosphates - add 1 ml of the filtrate, acidity with 10% HNO3 and add 2ml of ammonium molybdate reagent then boil and let it stand for few mins
• add 20ml of 10% h2so4 to the remaining filtrate in a beaker and boil gently for a few mins.

  ribose/pentose

  • test tube 1 - 1 ml sol. from the acid hydrolysis
  • 2 - 1ml of 0.1% of ribose sol
  • 3 - 1ml of 0.1% of glucose sol
• add 20ml of 10% h2so4 to the remaining filtrate in a beaker and boil gently for a few mins.

  purines

  • add 3 ml of 10% nh4h to 2ml of the filtrate then mix 2 to 3 drops of 5% AGNO3 solution to it
• A biopolymer of high molecular weight in which the repeating unit is mononucleotide.
• Major components of all cells making up 5-15% of the dry weight.
• Two structural classes of nucleic acid are deoxyribonucleic Acid (DNA) and ribonucleic Acid (RNA)
• • Spleen, liver, thymus, and pancreas are rich in nucleic acids.
• Brains or muscle tissues have much lower concentration.
• In tissues, with high nuclear/cytoplasmic ratio, the DNA, with thymus as the best source and spleen as a good substitute.
• Tissues with high cytoplasmic volume is rich in RNA
• Unicellular fungus, saccharomyces cerevisiae (yeast) contains 4% RNA by weight.
• nucleic acids - Sparingly soluble in cold water, insoluble in alcohol, but readily soluble in weak alkali with the formation of alkali metal salts.
• nucleic acids - They are precipitated from alkaline solution by the addition of acid.
• results

  nucleoproteins - purple color w precipitate

  • there is a presence of proteins

  purine bases - cloudy w yellow precipitate

  • there is a presence of purine

  ribose - no visible changes, negative in bial's test

  • no presence of ribose

  phosphates - yellow precipitation

  • there is a presence of phosphates
• Yeast cells have a high RNA-to-protein ratio compared to many other organisms.
• Bases found in nucleic acids are adenine and guanine
• materials

  • mortar and pestle
  • beaker
  • graduated cylinder
  • pipette
  • aspirator
  • watch glass
  • tripod
  • bunsen burner
  • test tube
  • cheesecloth
  • filter paper

  reagents

  • 5% ammonium molybdate
  • 0.1% ribose sol
  • 0.1% glucose sol
  • bial orcinol reagent
  • 10% nh4oh
  • 5% agno3
  • yeast
  • white sand
  • 0.2% naoh
  • 10% naoh
  • 1% cuso4
  • 10% h2so4
  • 10% hno3