1. T RANSCRIPTION / T RANSLATION Protein Synthesis

2. RNA RIBONUCLEIC ACID SINGLE STRANDED RESPONSIBLE FOR BRINGING THE GENETIC INFO. FROM THE NUCLEUS TO THE CYTOSOL!

3. RNA N UCLEOTIDE Phosphate group Sugar molecule (ribose) Nitrogenous bases Adenine – URACIL Cytosine - guanine

4. RNA *

5. 3 K INDS OF RNA mRNA – (messenger) brings info from DNA in nucleus to cytosol in eukaryotic cells (uncoiled) tRNA –(transfer) brings amino acids to mRNA for translation (hairpin shape) rRNA –(ribosomal) most abundant, rRNA makes up the ribosomes where proteins are made (globular)

6. TRANSCRIPTION!! DNA  RNA 1. INITIATION PHASE - RNA polymerase-initiates transcription by binding to region on DNA called PROMOTER (beginning of the gene) only ONE of the DNA chains will be used for transcription it’s called the TEMPLATE (promoter dictates which of the two strands will be used) 2. ELONGATION PHASE- RNA POLYMERASE attached to first DNA nucleotide of template chain – then begins adding complementary RNA nucleotides- Read in a 3’ to 5’ direction

7. C ONT. T RANSCRIPTION 3. TERMINATION PHASE- transcription continues until RNA polymerase reaches a TERMINATION SIGNAL on the DNA- STOP CODON 4. RNA polymerase releases both the DNA mol. And newly formed RNA mol.

8. T RANSCRIPTION

12. RNA REPLICATIONS

13. PROKARYOTES Transcription and translation occur in the SAME place! NO NUCLEUS!

14. E UKARYOTES 1. Before RNA leaves the nucleus: 5’ G (guanine) cap is attached 3’ polyA (adenine) tail is attached “many” 2. These protect the RNA from attach by cellular enzymes and help ribosomes to recognize the mRNA cap & tail are NOT translated

15. C ONT. E UKARYOTES 3. INTRONS (non coding sequence) are removed 4. EXONS (part of gene that are expressed) are joined to produce a mRNA molecule with a continuous coding sequence. NOW RNA CAN LEAVE THE NUCLEUS!

17. P ROTEIN S YNTHESIS PROTEINS CARRY OUT THE GENETIC INSTRUCTIONS ENCODED IN AN ORGANISM’S DNA!!!!

18. TRANSLATION T HE PROCESS OF ASSEMBLING FROM INFO. E NCODED IN A M RNA! 1. mRNA leaves nucleus 2. mRNA migrates to ribosome in cytosol for protein synthesis 3.amino acids floating in cytosol are transported to ribosomes by tRNA mole 4. peptide bonds join the amino acids to make polypeptide chain

19. V OCABULARY ! 1. GENETIC CODE: correlation between a nucleotide sequence and an amino acid sequence 2. CODON: 3 mRNA nucleotides, codes for a specific amino acid (64) 3. START CODON (AUG) & a.a. methionine 4. STOP CODON (UAA, UAG, UGA) 5. ANTICODON – 3 tRNA nucleotides carrying a specific amino acid!

20. 20 DIFFERENT KINDS OF AMINO ACIDS ….. But only 4 different kinds of nitrogen bases

21. I NITIATION C ODON M ARKS THE S TART OF AN M RNA MESSAGE 3 PHASES: 1. INITIATION 2. ELONGATION 3. TERMINATION

22. R IBOSOME FACTORY FOR POLYPEPTIDES Two subunits: Large subunit (top) Small subunit (bottom)

23. P SITE – HOLDS T RNA CARRYING GROWING POLYPEPTIDE A S ITE – HOLDS T RNA CARRYING THE NEXT AMINO ACID TO BE ADDED

25. Forms a peptide bond

27. P ROTEIN S YNTHESIS *

28. !

29. THE SUMMARY!- C ENTRAL D OGMA