PROTEIN SYNTHESIS WORKSHEET
PART A. Read the following:
Protein synthesis is the process used by the body to make proteins. The first step of protein synthesis is called
Transcription. It occurs in the nucleus. During transcription, mRNA transcribes (copies) DNA. DNA is
“unzipped” and the mRNA strand copies a strand of DNA. Once it does this, mRNA leaves the nucleus and
goes into the cytoplasm. mRNA will then attach itself to a ribosome. The strand of mRNA is then read in order
to make protein. They are read 3 bases at a time. These bases are called codons. tRNA is the fetching puppy.
It brings the amino acids to the ribosome to help make the protein. The 3 bases on tRNA are called anti-codons.
Remember, amino acids are the building blocks for protein. On the mRNA strand, there are start and stop
codons. Your body knows where to start and stop making certain proteins. Just like when we read a sentence,
we know when to start reading by the capitalized word and when to stop by the period.
Ribosome mRNA DNA
tRNA
mRNA
PART B. Answer the following questions on your paper:
1. What is the first step of protein synthesis? _________________________________
2. What is the second step of protein synthesis? _________________________________
3. Where does the first step of protein synthesis occur? _________________________________
4. Where does the second step of protein synthesis occur? ____________________________
5. Nitrogen bases are read ________ bases at a time.
6. The bases on the mRNA strand are called ______________________.
7. The bases on tRNA are called ______________________.
8. What is the start codon? ______________
9. What are the stop codons? (Use your mRNA chart or pg. 298) _______________________________
10. A bunch of amino acids attached together is called a _____________________________.
