Lec

• DNA

  Double-stranded, helical nucleic acid molecule

  
• Nucleotide

  A building block of DNA or RNA, consisting of a sugar, a nitrogenous base and a phosphate group.

  
• Double helix


  A pair of parallel helices intertwined about a common axis

  
• Hydrogen bond

  A type of weak chemical bond formed between the nitrogenous bases on opposite strands of DNA.

  
• Sequence

  The order of nucleotides in DNA or RNA or the order of amino acids in a protein.

  
• Deoxyribose


  DNA sugar

  
• Griffiths

  The transforming principle, transformed R strain into S strain in mice

  
• Hershey and Chase


  Used S labeled protein and P labeled DNA to show DNA is essential for bacteriophage replication

  
• Monomer of DNA

  Nucleotide

  
• Components of a nucleotide

  Nitrogenous base, phosphate, pentose sugar

  
• Phosphodiester bond


  Covalent bond connecting nucleotides together

  
• Antiparallel structure


  One strand 3' to 5' and other strand 5' to 3

  
• Chargaff's rules - 1

  A pairs with T and G pairs with C

  
• Rosalind Frankin


  X ray crystallography study
• Watson and Crick


  Elucidated the 3D structure of DNA

  
• Avery, MacLeod and McCarty


  Used degradative enzymes to identify the transforming principle
• Chargaff's rules - 2

  Relative composition varies from species to species
• Purines

  Adenine and guanine
• Pyrimidines


  Cytosine and thymine
• The most common DNA conformation

  B
• Promoter

  Region of a gene that controls expression
• +1 base

  1st base of the gene
• Enhancer


  Enhance the activity of a promoter due to their association with proteins called transcription factors
• Pseudogene


  DNA sequence that looks like it codes for a gene, but does not result in a protein
• Nucleosome

  DNA wrapped around a histone octamer
• Basic unit of DNA packaging in eukaryotes

  Nucleosome
• Euchromatin

  Beads on a string
• Heterochromatin

  Multiple nucleosomes wrapped into 30 nm fibre, aka Solenoid
• Sister chromatids


  Halves of a chromosome
• Telomere

  End of the chromosome
• Utility of pedigrees

  Tracking human transmission since we can't do human breeding experiments, Experimental matings where the number of offspring are few
• Proband


  First affected family member coming to the attention of geneticist
• Mating between related persons

  Consanguinity
• A chart that shows traits in a family from generation to generation

  Pedigree

  
• Sex unknown

  
• Exhibit the trait

  
• Fraternal twins

  
• Identical twins

  
• Consanguineous marriage

  
• Skips generations, equal male and females affected

  Autosomal recessive