Download presentation
Presentation is loading. Please wait.
Published bySamuel Gordon Modified over 9 years ago
2
Watson & Crick Beedle & Tatum
3
Processes: Transcription (DNA to mRNA) Translation (mRNA to protein) Importance of location Eukaryotes Prokaryotes
4
Review Types of RNA in Gene Expression mRNA (messenger)-provides code for protein tRNA (transfer)-carries amino acids rRNA (ribosomal)-directs translation
5
Requires DNA-dependent RNA Polymerase ▪ Core enzyme + sigma factor = holoenzyme Three forms in Eukaryotic Nuclei ▪ RNA Pol I –Pre-rRNA ▪ RNA Pol II**--Pre-mRNA ▪ RNA pol III –Pre-tRNA
6
RNA recognizes region to be transcribed Promotor regions ▪ TATA box ▪ CAAT box
7
Complementary mRNA produced from DNA
8
Often zones with high GC levels Loop and release of mRNA Protection 5’ capped with 7-methyl G 3’ tail polyadenylation
9
Prokaryotic cells translate immediately into protein Eukaryotic cells process mRNA before translation occurs Cutting out Introns Protecting transcript
10
Splicing occurs by sequence snRNA and snRNP (spliceosomes), and/or ribozymes (self-splicing enzymes) Many different proteins can result from one transcript
12
mRNA Transcript tRNA Carrier for amino acids Ribosomes Two sub-units of protein with three pieces of RNA
13
Codons- 3 nucleotide codes for amino acids 20 amino acides 64 codons 3 stop codons (UGA, UAA, UAG) 1 Start codon (AUG-methionine) Each codon brings in a tRNA anti-codon that contributes one amino acid to the protein
14
Small sub-unit of ribosome binds to mRNA Methionine “start” Large sub-unit of ribosome enters Initiation factors involved
15
Connection Next tRNA enters 1 st tRNA “hands” amino acid to 2 nd tRNA, then leaves Ribosome slides to free the next space Continuation for length of protein Elongation factors involved
17
Stop Codon is reached RF’s bind to stop codon Protein is released Ribosomal units disassociate
18
Exploring factors influencing gene expression Expression and repression of genes
19
Brooker, R. J. (2011). Concepts of Genetics + Connect Plus Access Card. McGraw-Hill Science Engineering, New York, NY. Brooker, R. J., (2012). Genetics: analysis and principles. 4th Ed. McGraw- Hill Higher Education, New York, NY. King, M. D. (2013). The Medical Biochemistry Page. Retrieved from: http://themedicalbiochemistrypage.org/home.html. http://themedicalbiochemistrypage.org/home.html. McClean, P. E. (2013). Transcription. Retrieved from: http://www.ndsu.edu/pubweb/~mcclean/plsc731/transcript/transcript1.ht m http://www.ndsu.edu/pubweb/~mcclean/plsc731/transcript/transcript1.ht m Unknown (2013). Three types of RNA polymerase in eukaryotic nuclei. Retrieved from: http://mcb.berkeley.edu/courses/mcb110/ZHOU/lec.5- 7.euk_trxn_apparatus.pdfhttp://mcb.berkeley.edu/courses/mcb110/ZHOU/lec.5- 7.euk_trxn_apparatus.pdf
20
Cap & Tail http://classconnection.s3.amazonaws.com/681/flashcards/894681/jpg/co ding1330783434942.jpg http://classconnection.s3.amazonaws.com/681/flashcards/894681/jpg/co ding1330783434942.jpg RNA Elongation http://limbiclab.files.wordpress.com/2012/12/limbic_lab_dna_transcripti on_diagram1.png http://limbiclab.files.wordpress.com/2012/12/limbic_lab_dna_transcripti on_diagram1.png RNA Initiation http://9e.devbio.com/images/ch05/0503fig1.gifhttp://9e.devbio.com/images/ch05/0503fig1.gif Processing http://www.genomebc.ca/glossary/Alternative%20Splicing%20(colourful )_Image.gif http://www.genomebc.ca/glossary/Alternative%20Splicing%20(colourful )_Image.gif Translation Initiation http://kvhs.nbed.nb.ca/gallant/biology/translation_initiation.jpg http://kvhs.nbed.nb.ca/gallant/biology/translation_initiation.jpg Translation Elongation http://kvhs.nbed.nb.ca/gallant/biology/translation_elongation.jpg http://kvhs.nbed.nb.ca/gallant/biology/translation_elongation.jpg Translation Termination http://utminers.utep.edu/rwebb/assets/images/17.17_Termination_of_tra nsla.jpg http://utminers.utep.edu/rwebb/assets/images/17.17_Termination_of_tra nsla.jpg
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.