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DNA Primer JL Lo and HC Lee 2000 June-July
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Introduction protein_2.ps intro1.ps
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What is DNA ( 去氧核糖核酸 )? Huge 1D molecule - two strands of nucleotides – double helix Information for life Cell > DNA > Nucleotide ( 核甘酸 ) > Base pair Nucleotide bases( 鹼基 ) –Guanine (G) , Adenine (A), Cytosine (C) Thymine (T)
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Structure of DNA
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Nucleotides
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Bases of Nucleotides 核甘酸的鹼基 Pyrimidine 嘧啶(鹼基) –T (Thymine) 胸腺嘧啶 –C (Cytosine) 胞嘧啶 Purine 漂呤(鹼基) –A (Adenine) 胺漂呤 –G (Guanine) 鳥漂呤
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How big is the Human Genome? Contains over 3 billion base pairs One meter long when fully streched Size of 6 billion genomes, one from each person on earth = 1 meter long human hair 150000 times under electron micrograph
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Scale Comparison
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What is a Gene? One Gene One Protein Over 100,000 genes reside in the human genome Each gene (DNA sequence) contains the genetic code of a protein (amino acid sequence) Gene to protein transcription translation
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From DNA to Protein (I) Transcription 轉錄 –Copies and splices a gene (single strand of DNA sequence) into an mRNA sequence Translation 翻譯 –Converts mRNA into a protein (string of amino acids) Promoter –tells the cell when to turn on the gene and how much transcription will occur
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From DNA to protein (II) Beginner's guide to Molecular Biology.htm
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Transcription 轉錄 Start signal (e.g. TATAAT) and stop signal (e.g. AAAAA) Splicing: keep exons 外碼子, throw out intron 內碼子 mRNA: concatena- tion of exons
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Transcription I - copying
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Transcription II - splicing
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Translation 翻譯 Genetic code: –3-nucleotides = a CODON 64 codons ( 密碼子 ) –3 stop codons –Rest (61) codes to 20 amino acids Figure gene.pdfgene.pdf
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Human Chromosome Genomes Guide Homo sapiens.htm
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Chromosome Packing
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Mutation of Chromosome
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Mitosis
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Meiosis
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