Protein Synthesis AP Ch 17

Unit Review Unit 5: Cellular Biology Unit 6A: Cellular Biology Cells Reproduce (mitosis, meiosis, binary fission) Unit 6A: Cellular Biology DNA (structures and functions) Unit 6B: Cellular Biology Gene expression (DNA provides instruction for protein biosynthesis) Unit 6C: Genetics The logical conclusion of unit 5 & 6: DNA is passed from parent to offspring b/c meiosis Genes within the DNA are used to build proteins Protein traits are a macroscopic visual to inheritance!

Vocab Review Protein: Protein Synthesis: Gene Expression: Carbon-based molecules that build living organisms Protein Synthesis: Process in which cells construct protein macromolecules Gene Expression: Sections of DNA provide instructions to build protein biosynthesis

Molecule Review

Protein Synthesis Overview DNA contains the chemical code for life mRNA copies DNA (Transcription) mRNA edits the code (RNA processing) tRNA decodes mRNA (Translation) Amino acids are linked to form protein

Part I: Transcription

Transcription DNA contains the instructions for making protein (nucleus) Proteins (T.f.) attach to DNA at a promoter region RNA polymerase attaches to proteins and uses one strand of DNA as a template and reads 3’  5’

Transcription Complimentary RNA nucleotides are assembled into RNA transcript. RNA transcript separates from DNA at a terminating sequence*

Transcription Animation http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf http://bcs.whfreeman.com/thelifewire/content/chp12/1202001.html http://www.youtube.com/watch?v=41_Ne5mS2ls

Part II: RNA processing

RNA processing A U G A U A G C G C A U Only fragments of a gene make a protein mRNA is edited before leaving the nucleus A U G A U A G C G C A U 5’ 3’

RNA processing Exon Intron Exon A U G A U A G C G C A U mRNA is made up of introns and exons Introns: noncoding DNA Exons: expressed DNA Exon Intron Exon A U G A U A G C G C A U 5’ 3’

RNA processing Spliceosome A U G A U A G C G C A U Enzymes remove intron & connect exons Spliceosome A U G A U A G C G C A U 5’ 3’

GTP A A A A A A RNA processing A U G G C G C A U Enzymes remove intron & connect exons Enzymes attach 5’ GTP cap & poly-A tail mRNA leaves through nuclear pores GTP A A A A A A A U G G C G C A U 5’ 3’

RNA processing animation http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120077/bio30.swf::How%20Spliceosomes%20Process%20RNA

Part III: Translation

Before we begin… There are 22 amino acids on Planet Earth Every tRNA attaches to one amino acid

Translation mRNA travels through the cytoplasm to the ribosome

Translation tRNA brings amino acid based upon mRNA codon Amino acids are linked through peptide bonds tRNA continues to bring amino acids until a stop codon is reached Polypeptide chain is released & protein is complete

Translation Animations http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/translation.swf http://highered.mcgraw-hill.com/olc/dl/120077/micro06.swf http://www.youtube.com/watch?v=41_Ne5mS2ls

mRNA, tRNA, & Amino acids mRNA codon is used with a decoder chart to determine the correct amino acid associated with tRNA

Codon Chart CODON = AUG A U G Amino acid is methionine Try finding the amino acid for the codon ‘CUA’ LEUCINE

Gene Expression