Nucleic Acids

• Messenger RNA - mRNA


  Carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm

  Serves as a template for protein synthesis

  
• Transfer RNA - tRNA


  Transports and places amino acids to the correct position on the mRNA strand to form a polypeptide chain.

  
• Ribosomal RNA - rRNA


  Type of RNA that makes up ribosomes. Produced in the nucleolus. Also catalyzes protein synthesis.
• What is a nucleotide?

  A nucleotide is the basic building block of DNA and RNA, consisting of a sugar molecule, a phosphate group, and a nitrogenous base.
• DNA

  Deoxyribonucleic Acid - Made up of Deoxyribose sugar (one less oxygen)

  Makes DNA have a negative charge.

  
• RNA


  Ribonucleic Acid - Made up of Ribose sugar (one more oxygen)

  Makes RNA have positive charge

  
• Nucleotide Bases

  • Five types of bases
  • Adenine
  • Guanine
  • Cytosine
  • Thymine (DNA ONLY)
  • Uracil (RNA ONLY)
• Complementary base pairs - DNA


  A=T

  C=G
• Complementary base pairs - RNA

  A=U

  G=C

  If thymine is present in the strand, it will still pair with Adenine.
• Prymidines

  Single-ring structures (1 carbon ring), pairs with purines, cytosine, thymine and uracil, smaller than purines.
• Purines

  Double-ring structures (2 carbon rings), pairs with pyrimidines, Adenine and Guanine, Larger than pyrimidines.
• What is DNA?

  • Deoxyribonucleic Acid
  • Contains deoxyribose sugar which has one less oxygen than ribose
  • Type of nucleic acid
  • Antiparallel nucleotide chains
  • Structure is double-helix model
  • Located in nucleus, chloroplast and mitochondria
• What is RNA?

  • Ribonucleic acid
  • Type of nucleic acid
  • Single-stranded
  • Contains ribose sugar which has one more oxygen than deoxyribose
  • 3 types - mRNA, rRNA, tRNA
• Monomer of Nucleic Acids - Nucleotides

  • Condensation reaction between sugar and base, sugar and phosphate
  • Phosphodiester linkage/bond between phosphate of one, sugar of other in dinucleotides

  A) Phosphate

  B) Nitrogenous Base

  C) Condensation reaction

  D) Phosphodiester Bond

  E) Sugar, deoxyribose or ribose

  
• Structure of DNA

  • Antiparallel
  • Double helix molecule
  • 3' end - Sugar end
  • 5' end - Phosphate end
  • Nucleotides join from 3' end

  
• DNA 3' A T C G T A G 5'

  RNA 5' U A G C A U C 3'
• Transcription is the process of DNA being copied into RNA via RNA polymerase to make mRNA.
• Translation is the process of amino acids being transferred onto mRNA strand via tRNA to form a polypeptide chain.
• Chargaff's Rule

  • Amount of Adenine ≈ Amount of Thymine (DNA)
  • Amount of Cytosine ≈ Amount of Guanine (DNA)
  • More energy needed to break C and G as 3 hydrogen bonds
  • Less energy needed to break A and T as 2 hydrogen bonds