DNA and RNA

• DNA contains deoxyribonucleotides, while RNA contains ribonucleotides.
• 3 components- phosphate groups, nitrogenous base, pentose sugar
• Purine (double ring)- adenine or guamine
• Pyrimidines (single ring)- Thymine, cytosine, uracil
• Nucleosides (2)- base + sugar
• Nucleotides (3) base+ sugar+ phosphate
• Nucleotides are linked together using Phosphodiester Linkage
• Phosphate connects 5' carbon to 3' carbon
• Phosphates and sugar molecules form backbone of nucleic acid strand
• Griffith's experiment:

  • Discovered the law of transformation
  • Put blood from a heat-treated S-strain to kill off the deadly part and also put R-strain in there
  • R-strain transformed into virulent and killed the mice
• Avery's experiment:

  • DNA is the only macromolecule that can transfer information
  • Heat-treated type S cells into 4 different groups and treated each group with DNase, RNase, and protease
  • Combined them with type R, similar to Griffith's experiment
• Hershey and Chase experiment:

  • Used bacteriophage to discover that DNA is the genetic material
  • DNA from bacteriophage is injected into bacterium during infections
• Pauling experiment:

  • Proposed helical structure for proteins and pioneered the use of physical models
  • Used ball-and-stick models and internal bonds for stabilizing
  • Discovered the structure
• Franklin experiment:

  • Used x-ray diffraction to discover the structure of DNA
  • Found out it's double-stranded and has 10 base pairs at each turn
• Chargaff experiment:

  • Discovered base pairs by separating different portions of DNA and realizing that different components complement each other
• Watson and Crick experiment:

  • Put together the final structure of DNA
• Components of a nucleotide:

  • Phosphate groups
  • Pentose sugar (deoxyribose or ribose)
  • Nitrogenous base (purines or pyrimidines)
• Purines:

  • Double ring, adenine or guanine
• Pyrimidines:

  • Single ring, thymine, cytosine, and uracil
• DNA differs from RNA:

  • DNA is double-stranded, includes deoxyribonucleic acid, uses thymine instead of uracil
• Bonds found within the DNA and backbone:

  • Hydrogen bonds are found between DNA and backbone
  • Between the base pairs
  • Multiple hydrogen bonds
• Key characteristics of DNA and RNA:

  • DNA: double-stranded, contains genetic information, runs antiparallel (5' to 3' and 3' to 5')
  • RNA: single-stranded, uses uracil instead of thymine
• Common type of DNA in living organisms:

  • B-DNA