1 / 20

Transcription: DNA  mRNA

Transcription: DNA  mRNA. Remember…. DNA is the genetic code and is found in the nucleus . The genetic code is used to make proteins , which you are made of. But…proteins are made on the ribosomes. Remember…. nucleus. DNA. So how does the code get from the nucleus to the ribosomes?.

ahumphries
Download Presentation

Transcription: DNA  mRNA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Transcription:DNA  mRNA

  2. Remember… • DNA is the genetic code and is found in the nucleus. • The genetic code is used to make proteins, which you are made of. • But…proteins are made on the ribosomes.

  3. Remember… nucleus DNA

  4. So how does the code get from the nucleus to the ribosomes? RNA

  5. Structure of RNA • RNA differs from DNA in 3 ways: • RNA is a single strand. • RNA has the sugar ribose. • RNA has the nitrogen base uracil instead of thymine.

  6. Structure of RNA Single strand

  7. 3 Types of RNA • Messenger RNA (mRNA) • Ribosomal RNA (rRNA) • Transfer RNA (tRNA)

  8. mRNA • mRNA delivers the instructions for making a protein from the nucleus to a ribosomein the cytoplasm.

  9. Transcription • DNA cannot leave the nucleus. • However, its code can be copied by mRNA and taken out of the nucleus.

  10. Transcription • First, the enzyme RNA polymerase binds to DNA and separates the DNA strands.

  11. Transcription • Then, a strand of mRNA is transcribed (copied) using one DNA strand as a template.

  12. Transcription • To copy the code, RNA nucleotides are added using the base pairing rules for DNA, except that in RNA, uracil pairs with adenine. • (G – C, A – U)

  13. Practice Transcribing • Let’s practice transcribing a strand of DNA: • DNA: G T C A G A T A C • mRNA:________________ C A G U C U A U G

  14. Transcription Animation • http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf

  15. RNA Processing • The sequences that code for proteins are called exons because they are “expressed” in the synthesis of proteins. • The introns do not code for proteins and are cut out of the mRNA sequence before it leaves the nucleus. • The remaining exons are spliced together.

  16. After Transcription • The single strand of mRNA leaves the nucleus and enters the cytoplasm. • It will then travel to a ribosome where its code will be translated into a protein.

  17. After Transcription

  18. Transcription & Translation Transcription Translation In the nucleus In the cytoplasm (ribosome)

More Related