Honors Bio Class 22

Today in class we reviewed the the process of protein synthesis. In a prokaryotic cell protein synthesis takes place in two main steps; transcription and translation. In eukaryotic cells the mRNA is transcripted twice, first inside the Cell nucleus and second, outside the the nucleus in the cytoplasm. RNA polymerase is needed to create mRNA in order to code for the protein. Before we can use the mRNA, the spliceosome needs to cut out all the introns that are useless when coding for the protein.In both cells, tRNA is used to collect the amino acids that are floating around the cytoplasm. tRNA and the amino acid are connected by the enzyme tRNA aminoacyl synthetase. Once they are bonded both the amino acid and the mRNA and the tRNA are moved to the ribosome. The ribosome will begin to read the mRNA in the 5' to 3' direction. Depending on the codons, certain tRNAs with matching codons will be accepted into the ribosome. The tRNAs will bring with them, their amino acid which will create a polypeptide chain which will eventually create a protein.