Objective: Journal: Describe the process of protein synthesis Explain how a disruption in the sequence can cause a change in appearance Journal: List two reasons why cells divide.

Protein Synthesis The making of protein

RNA Full Name: Ribonucleic Acid Structure: Helix Number of Strands: One

Ribose The sugar in RNA (Deoxyribose = DNA) Contains four –OH groups

Nitrogen Bases in RNA Adenine (A) Guanine (G) Cytosine (C) Uracil (U) **There is no thymine in RNA, instead adenine pairs with uracil.

Types of RNA Messenger RNA (mRNA) Transfer RNA (tRNA) Copies code from DNA and brings it to the ribosome Transfer RNA (tRNA) Brings amino acids to ribosome to assemble into protein

Transcription 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

After transcription… mRNA leaves the nucleus and heads out into the cytoplasm

Starting Translation A ribosome then binds to the mRNA at a 3- letter start signal called a start codon Start codon = AUG = Methionine (MET) Codon isa sequence of three nucleotides that are read together

Translation Continued… Then tRNA comes over tRNA carries an amino acid on one end and an anti-codon on the other end mRNA bases will be read in groups of 3 called codons by the tRNA

Translation Continued… tRNA brings over the corresponding amino acid based on the mRNA sequence Each codon codes for 1 amino acid As the next codon is read, the next amino acid is brought over by another tRNA

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