22 4 nucleotides 20 amino acid 4x4x4=64 > 20 triplet code (codon) This genetic code is universally used by all living things today with only a few exceptions.
23 1.2.4 Open Reading Frames A substring in DNA that contains no stop codons (UAA, UAG, UGA) while reading in a single reading frame. How can one detect ORFs? Long ORFs are easy, since the probability that a stop codon appears randomly is 3/64.
24 1.2.5 Introns and Exons eukaryotes ˇ prokaryotes × Extreme example cystic fibrosis: 24 introns, 1K/1M nts splicing & alternative splicing
50 1.6 Genomic Information Content (Before sequencing is available…) C-Value Paradox The amount of DNA in every cell of a given organism is the same. C-Value paradox: complexity & genome size are not correlated.
52 Reassociation Kinetics R. Britten et al, 1960s cot equation: c 0 t 1/2 measures the weight (or amount) non-repeated sequences. t 1/2 : time for renaturing (i.e. c/c 0 =0.5)
53 參考資料及圖片出處 1. Biochemistry, by J. M. Berg, J. L. Tymoczko, and L. Stryer, Fith Edition, 2001. Biochemistry 2. DNA 的 14 堂課, by Karl Drlica, 1996, 周業仁 翻譯, 天下文化, 2002 翻譯. DNA 的 14 堂課 3. 多數圖片來自課本 Fundamental Concepts of Bioinformatics Fundamental Concepts of Bioinformatics Dan E. Krane and Michael L. Raymer, Benjamin/Cummings, 2003.