Protein Synthesis Practice Worksheet

Protein Synthesis and Codons Practice

Protein synthesis is the process where a sequence of DNA is used to build a protein from individual amino acids. The first step in this process is called TRANSCRIPTION, where a coding region of DNA is converted to messenger RNA (mRNA). During transcription, mRNA is made from the DNA sequence following the base pair rule, except RNA does not contain the base Thymine, but instead has Uracil. The mRNA then leaves the nucleus and goes to a ribosome in the cell's cytoplasm. The ribosome reads the message three bases at a time, called a CODON. Each codon will specify a single amino acid. The amino acids are joined together and folded into a protein, a process called TRANSLATION

Key Points:

• DNA is used to make a copy of mRNA (transcription)

• mRNA leaves the nucleus and goes to ribosomes

• 3 bases = codon

• 1 codon = a single amino acid

• A chain of amino acids = a protein

• Protein synthesis is also called translation

Biologists use a codon chart or a codon wheel to determine the amino acids. Amino acids are usually abbreviated on these charts as three letter words, like Cys and Ser.