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MEDICAL ANIMATION TRANSCRIPT: Protein synthesis is the process by which the body creates proteins. Proteins consist of chains of amino acids. Which amino acids used and their sequence determines each particular protein. The assembly of amino acids into proteins takes place in cells. The first stage, transcription, occurs in the nucleus. The second stage, translation, occurs in the cytoplasm. Transcription is the process of converting instructions for assembling a protein located in the cell's DNA into messenger RNA. The template for building messenger RNA is a genetic sequence along a section of the DNA strand. Each strand of DNA contains nucleotides with complementary bases. Adenine pairs with thymine, and cytosine with guanine. To start transcription, an enzyme called RNA polymerase attaches to the beginning of the DNA template. A sequence of three DNA bases called a base triplet contains information for assembling each amino acid of a protein. RNA polymerase reads the base triplets to build messenger RNA using free nucleotides. Corresponding messenger RNA triplets are called codons. In mRNA codons, uracil replaces thymine. Once the mRNA is built, certain enzymes remove introns or sections that will not be use to build the protein. Enzymes splice the remaining ends or exons together. Then the functional mRNA leaves the nucleus. Translation is the process of using messenger RNA to assemble amino acids into a protein. The structure that will read the mRNA, called a ribosome, attaches to the mRNA strand. Initiated by a start codon, the ribosome reads each subsequent codon, which signals a transfer RNA molecule that has the matching anti-codon sequence and specific amino acid. The process continues as additional transfer RNA molecules attach, bringing the correct amino acids to build the protein until the protein is completely assembled, signaled by the stop codon. After the assembled protein breaks away from the ribosome, its subunits detach from the mRNA. ♪ [music] ♪
#ProteinSynthesis #transcription #translation
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