Chapter 17 - Protein Synthesis Notes

Chapter 17 - Protein Synthesis Notes - CHAPTER 17- FROM...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
CHAPTER 17- FROM GENE TO PROTEIN Central Dogma of Molecular Biology (Flow of information in cells) DNA RNA PROTEINS   GENE  =  sequ en c e  of DNA with a  specific  function  (final product  = polypeptide  OR  RNA)     RNA's  = intermediates  between  DNA code  and  proteins  that determine  phenotype  For  each  gene  only  one  of the  two strands  is transcribed  into an  RNA (template  strand)  For  som e  genes  one  strand  may  be  used;  for other  gene s  the  comple m e ntary  strand  is used 3 KINDS OF RNA Mess eng er  RNA (mRNA)    Transfer  RNA (tRNA)   Riboso m al  RNA (rRNA)   MESSENGER RNA   carries  DNA mes sa g e  from  nucleus  to cytoplasm; mMessa g e  is read  in “triplets”  called   CODONS 64  different  codons  code  for 20  different  amino  acids;   AUG  = START  codon;  UAA, UAG,  UGA are  STOP  codons;   REDUNDANCY OR ”WOBBLE”  - codons  for sam e  amino  acid  can  differ  in 3 rd  base  Code = universal to all life (found in all organisms) = evidence for common ancestry Prokaryotes~ m-RNA functional as soon as transcribed Eukaryotes~ m-RNA must be processed before use           GTP "cap"  = METHYLATED  GUANINE added  to 5’ end;   for stability;                    prevents  degradation  used  to bind  mRNA  to ribosom e           PolyA "tail" added  to 3’ end  (AAA)-  stability; helps  passag e  through  nuclear  membrane DNA    DNA = REPLICATION DNA    RNA= TRANSCRIPTION RNA   PROTEINS  = TRANSLATION
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
In  EUKARYOTES mRNA is made  as pre-mRNA  containing: INTRONS - noncoding  DNA seg m e nts               may  provide  cross  over  places  without interrupting  code                 may  facilitate  evolution  of new  proteins  by   exon shuffling     •  EXONS  - coding  DNA seg m e nts;  code  for different   DOMAINS                      =structural/functional  regions snRNPs  (small  nuclear  ribonucleoproteins)  
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/14/2012 for the course BIO 151 taught by Professor Grinblat during the Fall '08 term at Wisconsin.

Page1 / 5

Chapter 17 - Protein Synthesis Notes - CHAPTER 17- FROM...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online