Download Inquiry-Protein Synthesis

Name: ______________________________________ Date: ___________ Hour: ________ Page: _________
Biology B
Inquiry-Protein Synthesis
Protein synthesis is the process your body goes through to make a protein. Protein synthesis is a two
part process that involves a second type of nucleic acid along with DNA. This second type of nucleic
acid is RNA, which stands for ribonucleic acid.
1. There are three things that make DNA and RNA different. One is that DNA contains the sugar
deoxyribose and RNA contains the sugar ribose. Look at the picture above-what are the other two
things that are different between DNA and RNA?
There are actually three types of RNA: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal
RNA (rRNA). Here are the roles of the three types of RNA:
-mRNA: carries the code to make the protein
-tRNA: brings the correct amino acid to the ribosome for translation
-rRNA: makes up ribosomal structure
Name: ______________________________________ Date: ___________ Hour: ________ Page: _________
Biology B
Transcription
In the first part of protein synthesis, the DNA will unwind and the two DNA strands will unzip from
each other. Similar to the way DNA replicates itself, a single strand of messenger RNA (mRNA) is
then made by pairing up mRNA nucleotides with the exposed DNA nucleotide bases.

The Process
Transcription occurs in the nucleus, and it uses the
leading strand of the DNA molecule.
2. Which nitrogen base of RNA base pairs to the
adenine on the DNA?
3. Which nitrogen base of RNA base pairs to thymine
on the DNA?
4. Which nitrogen base of RNA base pairs to guanine
on the DNA?
5. Which nitrogen base of RNA base pairs to cytosine
on the DNA?
6. You are given the following DNA sequence:
ATTGCGATTCGATAC-what would the mRNA sequence
be?
7. A codon is a sequence of three nitrogen bases on the
mRNA. How many codons are in the strand that you
sequenced above?
Translation
After the mRNA is made, it leaves the nucleus and travels to the ribosome. In the ribosome, the
mRNA code is translated into a protein sequence. In this process, each set of three mRNA bases (the
codon) will pair with a complimentary tRNA base triplet (called an anticodon). Each tRNA is specific
to an amino acid, as tRNA's are added to the sequence, amino acids are linked together by peptide
bonds, eventually forming a protein that is later released by the tRNA. We will learn more about this
in class.