Zoology-_Section_2[1] - The Central Dogma Genetics of...

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The Central Dogma Genetics of Animals Protein Synthesis DNA codes for proteins 1. Transcription= transfer of info from DNA to mRNA (in nucleus) 2. Translation= transfer of info from mRNA into a polypeptide (in cytoplasm—ribosomes) TRANSCRIPTION [110] Starts with ‘TATA’ box. A promoter region ThyAdeThyAde flanked by G’s and C’s 13.21 The Relationship Among RNA, the DNA Template Strand, and the DNA Coding Strand [113] *You read the template strands, to make RNA you use the template strand* [113][114][115] 13.25 Messenger RNA Processing [119] Exons and introns are DNA “ins stay in, ex’s exit” The remaining transcript goes out the nuclear pore Splicing only happens in Eukaryotes Most introns are “junk” or “garbage”. Prokaryotes do not have introns. [116][117][118] TRANSLATION 20 amino acids; 4 nucleotides 1:1 code: only 4 amino acids “doublet” code: only 16 amino acids “triplet” code: 64 amino acids [111]
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Genetic code is composed of mRNA U’s instead of T’s- first clue that it is mRNA instead of DNA [120] Translation- o mRNA language translated to polypeptide language Takes place at ribosome o tRNA is the translator: picks up amino acids recognizes codons on mRNA (contains anticodons) Ribosome- composed of RNA Has 2 parts- large sub-unit and small sub-unit [13.28 in text] [121-126] Ribosomal docks onto sequence. . first little then big Peptide bond is formed and ribosome shifts down the line and goes on and on and on until it reaches a stop codon [127] It’s kinda like… A library of books being read by someone Where… Library=All the cell’s DNA Book=one gene Reader= RNA polymerase She gives you a copy of the book but in a foreign language You have to translate the book Take out pocket translator and out comes the… language of amino acids OR Its kinda like… 1. Transcription= transposins/writing music from one key to another on a staff (still the “language” of notes on a page) 2. Translation= kind of like reading music from page to play an instrument (changing the language of written notes to the language of sound) What happens to mRNA after it is translated? They will be broken down eventually . (not used forever) Transcription and Translation Animation! www.dnai.org/index.htm
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Gene Regulation, Mutations, and Cancer AAG CTC TTA CGA ATA TTC - template strand(DNA) UUC GAG AAU GCU UAU AAG - mRNA AAG CUC UUA CGA AUA UUG - tRNA (anticodons) -nucleotides [13.18] [128-131] The repressor is BLOCKING transcription! When there is no lactose present, a repressor latches onto the DNA and keeps it from being transcribed. When there is lactose in the environment, the repressor reacts with it, and it comes off, allowing the DNA to be transcribed and the protein that digests the lactose to be produced. This happens in the bacteria in our stomach! Gene Regulation in Eukaryotes
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This note was uploaded on 05/25/2008 for the course ZOO 1114 taught by Professor Melodybrooks during the Spring '08 term at The University of Oklahoma.

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Zoology-_Section_2[1] - The Central Dogma Genetics of...

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