1.  Objective: ◦ Describe the process of protein synthesis ◦ Explain how a disruption in the sequence can cause a change in appearance  Journal: ◦ On the top of your note sheet, explain what DNA polymerase does in DNA replication.

2. The making of protein

3.  RNA’s function is to take DNA’s code, copy it and use it to make proteins  Differs from DNA in that: ◦ RNA is single stranded ◦ Contains Ribose as sugar ◦ Uracil instead of Thymine  U-A

4.  Messenger RNA (mRNA) ◦ Copies code from DNA and brings it to the ribosome  Transfer RNA (tRNA) ◦ Brings amino acids to ribosome to assemble into protein

5.  Transcription ◦ Creates mRNA from code contained in a gene (DNA)  Translation ◦ mRNA code is read and “translated” into a string of amino acids that make up a protein

6.  RNA polymerase “unzips” DNA at a gene  mRNA is built by pairing A-U and C-G  When gene ends, mRNA breaks away from DNA and DNA zips back up  http://www.stolaf.edu/people/giannini/fl ashanimat/molgenetics/transcription.swf http://www.stolaf.edu/people/giannini/fl ashanimat/molgenetics/transcription.swf

7.  mRNA leaves the nucleus and heads to a ribosome  mRNA “letters” will be read in groups of 3 called codons  Each codon codes for 1 amino acid

8.  mRNA binds to ribosome  tRNA brings over its amino acid  Next codon is read, next amino acid is brought over by another tRNA

9.  Amino Acids bond together forming a protein  Process repeats until ribosome reaches a stop codon  Protein is released  http://www.columbia.edu/cu/biology/cour ses/c2005/images/animtransln.gif http://www.columbia.edu/cu/biology/cour ses/c2005/images/animtransln.gif

10. TAC-AAA-GCT-TTT-CTA-CCG-ATC Mutations: changes in DNA sequence Point Mutation: affect one nucleotide 1. Substitutions – replace one of the nucleotides with another - Can be lethal TAC-AAG-GCT-TTT-CTA-CCG-ATC TAC-AAC-GCT-TTT-CTA-CCG-ATC OR

11. Frame shift mutations: Change the whole sequence by changing the order of how the sequence is read - Insertion or deletion– add or remove a nucleotide TAC-AAA-GCT-TTT-CTA-CCG-ATC TAC-AAA-GCT-TGT-TCT-ACC-GAT-C TAC-AAA-GCT-TTC-TAC-CGA-TC Remove Add In