ap biology 2005-2006 chapter 15. mutations ap biology 2005-2006 code is redundant several codons...
TRANSCRIPT
![Page 1: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/1.jpg)
AP Biology 2005-2006
Chapter 15.
Mutations
![Page 2: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/2.jpg)
AP Biology 2005-2006
Code is redundant several codons for
each amino acid “wobble” in the tRNA “wobble” in the
aminoacyl-tRNA synthetase enzyme that loads the tRNA
Universal code
![Page 3: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/3.jpg)
AP Biology 2005-2006
Mutations
When do mutations affect the next generation?
Point mutations single base change base-pair
substitution silent mutation
no amino acid change redundancy in code
missense change amino acid
nonsense change to stop codon
![Page 4: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/4.jpg)
AP Biology 2005-2006
Point mutation leads to Sickle cell anemiaWhat kind of mutation?
![Page 5: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/5.jpg)
AP Biology 2005-2006
Sickle cell anemia
![Page 6: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/6.jpg)
AP Biology 2005-2006
Mutations Frameshift
shift in the reading frame
changes everything “downstream”
insertions adding base(s)
deletions losing base(s)
![Page 7: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/7.jpg)
AP Biology 2005-2006
What’s thevalue of
mutations?
![Page 8: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/8.jpg)
AP Biology 2005-2006
Chapter 17.
RNAProcessing
![Page 9: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/9.jpg)
AP Biology 2005-2006
Transcription -- another look The process of transcription includes
many points of control when to start reading DNA where to start reading DNA where to stop reading DNA editing the mRNA protecting mRNA as it travels through
cell
![Page 10: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/10.jpg)
AP Biology 2005-2006
Primary transcript Processing mRNA
protecting RNA from RNase in cytoplasm add 5’ cap add polyA tail
remove introns
AUG UGA
![Page 11: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/11.jpg)
AP Biology 2005-2006
Protecting RNA 5’ cap added
G trinucleoside (G-P-P-P) protects mRNA
from RNase (hydrolytic enzymes)
3’ poly-A tail added 50-250 A’s protects mRNA
from RNase (hydrolytic enzymes) helps export of RNA from nucleus
UTR UTR
![Page 12: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/12.jpg)
AP Biology 2005-2006
Dicing & splicing mRNA Pre-mRNA mRNA
edit out introns intervening sequences
splice together exons expressed sequences
In higher eukaryotes 90% or more of gene can be intron no one knows why…yet
there’s a Nobel prize waiting…
“AVERAGE”…“gene” = 8000bpre-mRNA = 8000bmature mRNA = 1200bprotein = 400aalotsa “JUNK”!
![Page 13: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/13.jpg)
AP Biology 2005-2006
Discovery of Split genes1977 | 1993
Richard Roberts Philip Sharp
NE BioLabs MITadenovirus
common cold
![Page 14: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/14.jpg)
AP Biology 2005-2006
snRNPs small nuclear RNA RNA + proteins
Spliceosome several snRNPs recognize splice site
sequence cut & paste
RNA as ribozyme some mRNA can
splice itself RNA as enzyme
Splicing enzymes
![Page 15: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/15.jpg)
AP Biology 2005-2006
Ribozyme RNA as enzyme
Sidney Altman Thomas Cech
1982 | 1989
Yale U of Colorado
![Page 16: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/16.jpg)
AP Biology 2005-2006
Splicing details No room for mistakes!
editing & splicing must be exactly accurate a single base added or lost throws off the
reading frame
AUG|CGG|UCC|GAU|AAG|GGC|CAU
AUGCGGCTATGGGUCCGAUAAGGGCCAUAUGCGGUCCGAUAAGGGCCAU
AUG|CGG|GUC|CGA|UAA|GGG|CCA|U
AUGCGGCTATGGGUCCGAUAAGGGCCAUAUGCGGGUCCGAUAAGGGCCAU
Met|Arg|Ser|Asp|Lys|Gly|His
Met|Arg|Val|Arg|STOP|
![Page 17: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/17.jpg)
AP Biology 2005-2006
Alternative splicing Alternative mRNAs produced from same gene
when is an intron not an intron… different segments treated as exons
Hardto definea gene!
![Page 18: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/18.jpg)
AP Biology 2005-2006
Domains Modular architecture
of many proteins separate
functional & structural regions
coded by different exons in same “gene”
![Page 19: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/19.jpg)
AP Biology 2005-2006AAAAAAAAGTP
20-30b
3'
promoter transcriptionstop
transcriptionstart
introns
The Transcriptional unit (gene?)
transcriptional unitTAC ACT
DNA
DNATATA5'RNA
polymerase
pre-mRNA
5' 3'
translationstart
translationstop
mature mRNA
5' 3'
UTR UTR
exonsenhancer
1000+b
![Page 20: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/20.jpg)
AP Biology 2005-2006
Any Questions??
![Page 21: AP Biology 2005-2006 Chapter 15. Mutations AP Biology 2005-2006 Code is redundant several codons for each amino acid “wobble” in the tRNA “wobble”](https://reader036.vdocument.in/reader036/viewer/2022062301/56649ead5503460f94bb4af1/html5/thumbnails/21.jpg)
AP Biology 2005-2006
20-30b
3'
introns
The Transcriptional unit
transcriptional unitTAC ACTDNATATA
5'RNApolymerase
5' 3'
5' 3'
exonsenhancer
1000+b