Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

3.5 7.3 Dna Transcription


Published on

Published in: Health & Medicine, Technology
  • Be the first to comment

3.5 7.3 Dna Transcription

  1. 1. 3.5 & 7.3DNA Transcription<br />IB Biology<br />
  2. 2. Types of RNA:<br />rRNA: ribosomal RNA<br />Major component of ribosomes<br />tRNA: transfer RNA<br />Carries amino acids to mRNA<br />An interpreter in translation<br />mRNA: messenger RNA<br />Encodes genetic info from DNA and convey it to the ribosomes, where the info is translated into amino acid sequences<br />
  3. 3. Transcription<br />The process by which RNA is made from a DNA template<br />Purpose: to read the DNA, one gene at a time. <br />RNA polymerase starts transcription at promoters and end at terminators<br />Complimentary RNA strand is formed<br />RNA is assembled in the 5’ 3’ direction<br />Bubbles open- instead of unzipping<br />
  4. 4. DNA “words”…<br />DNA gives instructions.<br />The instructions are written in a language where words are ALWAYS three base pairs long.<br />Ex: AAT,CCG,GCA,TTC, etc.<br />Each is called a triplet.<br />
  5. 5. Triplets on DNA makeCodons on mRNA<br />Codon- genetic code made of one triplet of bases.<br />Codons are found on mRNA (messenger RNA)<br />
  6. 6. Formation of mRNA<br />Creates a “mirror image” of the triplets found on DNA (except TU)<br />mRNA then travels out of the nucleus and toward a ribosome.<br />The formation of RNA is called transcription<br />
  7. 7. New Enzyme- RNA Polymerase<br />Links together the growing chain of RNA nucleotides during transcription<br />Uses DNA as template<br />Similar to DNA polymerase but only facilitates a reaction on one side of the strand<br />
  8. 8. New Players:<br />Promoter- place on gene where RNA polymerase initially attaches.<br />Terminator- place on gene where transcription ends.<br />
  9. 9. New…the “Middle” Step<br />Transcription - beginning<br />Middle = mRNA processing<br />Translation - end<br />
  10. 10. RNA processing<br />Post-transcriptional<br />Introns- non-coding sequences are removed<br />Exons- coding sequences are spliced together<br />
  11. 11. IB Terms: Sense vs. Antisense strands<br />Sense strand - the “other” strand, not transcribed.<br />Antisense strand -the one mRNA attaches to, and is complimentary to.<br />mRNA is similar to the sense strand, except TU.<br />
  12. 12. The code is universal<br />The same codons are found in all living organisms.<br />