DNA & RNA Protein Synthesis

DNA vs RNA

DNA - carries the blueprint for the order of amino acids to be produced during protein synthesis. b. Messenger RNA (mRNA) - copies the DNA molecule in the nucleus during transcription and goes into the cytoplasm and attaches itself to a ribosome. One 3 letter unit in an mRNA chain is called a codon. c. Transfer RNA (tRNA) - drops off amino acids it is coded to carry at the ribsome. The 3 letter code is complementary to mRNA and this 3 letter code is called the anti-codon d. Ribosome (rRNA) - this is where protein synthesis occurs. (Where the protein is assembled) http://www.wiley.com/college/pratt/0471393878/student/animations/dna_replication/index.html http://www.bioteach.ubc.ca/TeachingResources/MolecularBiology/DNAReplication.swf

Determine the amino acids coded for by a strand of DNA 1. Determining codons from a strand of DNA Consider the following strand of DNA read from left to right:                                  T T A T G C T C C T A A When complementary base pairing occurs the following strand of  mRNA is obtained.                              A A U A C G A G G A U U The codons are read three letters at a time from the transcribed mRNA. The codons are:                                     A A U     A C G     A G G     A U U 2. Determining amino acids from mRNA codons Find the codons in the table of mRNA codons below and the amino acids they code for. AAU -Asparagine ACG - Threonine AGG - Arginine AUU -isoleucine 

5 steps in protein synthesis -DNA serves as a code for proteins -Transcription occurs. One strand of DNA serves as a template (blueprint) for the formation of mRNA. -after transcription, the newly formed mRNA goes into the cytoplasm and attaches to a ribosome. -tRNA which carry specific amino acids, have anticodons which bind complementarily with the mRNA codons -The ribosome moves along the mRNA strand reading each codon. The tRNA anticodon bonds to its complementary codon. The amino acid carried by the tRNA is bonded to the polypeptide. The ribosome moves down the mRNA strand one codon at a time releasing a tRNA as it does and making room for another tRNA carrying an amino acid to join the mRNA. http://www.youtube.com/watch?v=1PSwhTGFMxs&feature=related DNA QUIZ QUESTIONS

RNA Transcription http://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.html http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf

Transcription = DNA → RNA Translation = RNA → protein Here is an overview. Gene Expression: DNA- Proteins Transcription = DNA → RNA Translation = RNA → protein