12.3 Protein Synthesis (Translation)

Watch these animations and try to explain what is going on. ◦Animation 1Animation 1 ◦Animation 2Animation 2

Steps of Protein Synthesis 1. Transcription happens in the nucleus 2. mRNA moves out of the nucleus into the cytoplasm 3. Once in the cytoplasm, mRNA is used to make a protein

How does m-RNA tell the cell what to do?  mRNA is a message that codes for a protein  Proteins are made in the cytoplasm which work to keep the cell alive  Translation or protein synthesis is the process of making a protein  Proteins are made up of amino acids (small building blocks)  There are 20 different types of amino acids

Process of Translation 1. mRNA moves out of the nucleus and into the cytoplasm NUCLEUS mRNA

2. mRNA attaches to a ribosome (rRNA)

3. Transfer RNA (tRNA) decodes the mRNA and brings amino acids to build up the protein Anticodon (3 bases on tRNA): Matches up to codons on mRNA

4. Protein (chain of amino acids) detaches from ribosome and goes off to work in the cell

Reading the Genetic Code -Each mRNA codon (3 bases) = 1 Amino Acid -Amino Acids link together= 1 Protein

Start Codon= AUG (Methionine) Stop Codon= UAA, UAG, UGA (codes for NOTHING!) WHY?

Practice Using Your Codon Chart mRNA: AUG CCC GUA UGA Amino Acid Chain: Met-Pro-Val-Stop mRNA: AUG UCG GCA UAA Amino Acid Chain: Met-Ser-Ala-Stop

Practicing the process Practicing the process

Transcription Translation