Lab Report- Building Proteins from RNA
by: Scarlet Chuquitarco
Introduction: Building Proteins from RNA Lab
The purpose of this lab was to explore the molecular process of building proteins from
the information carried by RNA. The question that we ultimately tried to answer is, “How are
proteins built using the information provided by a molecule of RNA?” The hypothesis is if RNA
determines the sequence of amino acids in proteins and polypeptides by a two-step process,
then translation of the mRNA to tRNA takes place at the ribosome in the cytoplasm.
Materials:
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Helicase
Human cell
tRNA sequence
Protein structure chart
Procedure:
1.) Transcribe the information in DNA to mRNA
2.) Locate codons
3.) Translate mRNA
Groups:
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The experimental group are the codons.
The control group are the anticodons.
Data Collection and Organization:
Locating Codons:
Codons
AUG (start codon)
GUA
CUG
CCA
GUG
UAU
ACG
UCG
UAC
UGC
CAG
UGU
AUA
CGU
CGG
UAA (stop codon)
Pairing Codons to Anticodons and translating to Amino Acids
Codons
tRNA Anticodons
Amino Acid
Number of Water
molecules produced
AUG (start codon)
UAC
Met
0
GUA
CAU
Val
1
CUG
GAC
Leu
2
CCA
GGU
Pro
3
GUG
CAC
Val
4
UAU
AUA
Tyr
5
ACG
UGC
Thr
6
UCG
AGC
Ser
7
UAC
AUG
Tyr
8
UGC
ACG
Cys
9
CAG
GUC
Gln
10
UGU
ACA
Cys
11
AUA
UAU
lle
12
CGU
GCA
Arg
13
CGG
GCC
Arg
14
UAA (stop codon)
AUU
Stop (N/A)
15
Analysis:
These charts show the translation from mRNA to tRNA. It also shows how the amino
acids correlate with RNA. The chart Locating Codons lists the codons given to the student in
order. AUG is the starting codon and in this specific sequence UAA is the stop codon. These
codons connect with their anticodons and form an amino acid. The number of water molecules
produced stays steady throughout the second chart.
Conclusion:
RNA carries out the instructions encoded in DNA. Most biological activities are carried
out by proteins. Therefore, the accurate synthesis of proteins is critical to the proper functioning
of cells and organisms. The linear order of amino acids in each protein determines its
three-dimensional structure and activity. The three kinds of RNA molecules perform different
but cooperative functions in protein synthesis. Synthesis of all proteins chains begins with the
amino acid methionine. The start codon specifying this methionine is AUG. The three codons
UAA, UGA, and UAG do not specify amino acids but signify stop signals. The sequence of
codons that runs from a specific start site to a terminating codon is called a reading frame. The
precise linear array of ribonucleotides in groups of three in mRNA specifies the precise linear
sequence of amino acids in a protein. Therefore, in simplified terms, the hypothesis was
correct. First, the transcription of DNA to mRNA occurs in the nucleus. Secondly, mRNA is
translated to tRNA in the ribosome in the cytoplasm. TRNA recognizes and binds to its
corresponding codon in the ribosome. This creates an amino acid appropriate for the codon.
This occurs until the sequence reaches a stop signal. These amino acids are connected by a
series of peptide bonds and create a protein. Peptide bonds are formed by biochemical
reactions that extract a war molecule as it joins the amino group of one amino acid to the
carboxyl group of a neighboring amino acid.
To improve this lab investigation, a student could look further into why certain items are
necessary in the creation of proteins. For example, the student could look into the importance
of the water molecule being released. It is important to understand peptide bonds. There are
many places in this process that result in errors. For example, if the mRNA was not transcribed
correctly from the DNA it could create major problems in the creation of proteins. Another
possible source of errors is matching codons to their anticodons. If those codons do not meet
then the amino acids cannot meet. Amino acids must be connected in order to make a protein.