genbio

• Nuclein


  The material isolated by Friedrich Miescher when studying pus cells from surgical bandages
• Friedrich Miescher (1844-1895) isolated the material "nuclein"
• deoxyribose - deoxygenated sugar present in DNA
• ribose - sugar in RNA
• glycosidic acid - connects the pentose sugar to the nitrogenous base
• phosphoester bond - connects the phosphate group to the pentose sugar
• nucleoside - complex of a sugar and a base
• polypeptide chain - chain of the nucleotides showing sequences of nitrogenous bases
• Cyclic bases

  Purines and pyrimidines
• purines


  2 rings
• pyrimidines


  1 ring
• DNA helix


  The twisted ladder-like structure of the two strands of DNA
• ANTIPARALLEL


  Two strands of DNA going in opposite directions
• ANTIPARALLEL - The direction of the strands of the DNA are going in opposite directions
• Rosalind Franklin & Maurice Wilkins


  Performed x-ray crystallography technique to analyze the structure of DNA
• RNA


  Known to be single-stranded
• RNA Properties

  • RNA has the base uracil instead of thymine in DNA
  • RNA has ribose instead of deoxyribose in DNA
  • RNA is a product of transcription of DNA
• Amino acids


  Subunits or monomers of proteins
• Levels of protein structure

  • Primary structure
  • Secondary structure
  • Tertiary structure
  • Quaternary structure
• Primary structure


  • Amino acid to amino acid (Polypeptides)
  • Forms peptide bond
• Secondary structure


  • May be in the form of a helix or a pleated sheet
  • Forms hydrogen bond
• Tertiary structure


  • 3D structure
  • Stabilized by covalent and weak non-covalent interactions
• Quaternary structure


  • When multiple folded protein subunits form a single complex
  • Requires more complex molecular interactions
• Protein Data Bank (PDB)


  An enormous collection of published experiments on the structure of DNA, RNA and proteins
• Nucleotides


  Basic units of DNA, composed of a phosphate group (P), a sugar (deoxyribose), and a nitrogenous base (A, C, G, or T) that encodes genetic information
• Nucleic acid


  Main information-carrying molecules of the cell, and, by directing the process of protein synthesis, they determine the inherited characteristics of every living thing
• Central Dogma of Molecular Biology


  It describes the flow of genetic information from DNA to RNA to Proteins
• Replication


  • Semi-conservative
  • Each newly synthesized molecule contains 1 "parent template" strand and 1 new "daughter" strand
• Leading Strand


  Replicates continuously
• Lagging Strand


  Replicated discontinuously
• mRNA (Messenger RNA)


  Encodes amino acid sequence of a polypeptide
• tRNA (Transfer RNA)


  Brings amino acid into ribosomes during translation
• rRNA (Ribosomal RNA)


  With ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA
• snRNA (Small nuclear RNA)


  With proteins, forms complexes that are used in RNA processing in eukaryotes
• Okazaki Fragment


  The segment of DNA produced in lagging strand