Making Proteins

Steps to follow for TRANSCRIPTION

1. Place the model of the large cell on the lab bench.
2. Place a molecule of DNA in the nucleus of the cell.  Fill in the correct complementary base pairs.
3. Unzip the DNA molecule by cutting it in half with a pair of scissors.
4. Circle a nucleotide of the DNA molecule
5. Circle a triplet.
6. Use one half of the DNA helix and match it up with the mRNA molecule. Fill in the correct complementary base pairs on the mRNA molecule.
7. Circle a codon that contains uracil.
8. This takes care of transcription.  

Steps to follow for TRANSLATION

1. Move the mRNA strand to the ribosome of the cell
2. Match the first 3 mRNA codons with 3 matching tRNA anticodons.  Fill in the corresponding base pairs on the tRNA molecule.
3. Notice the amino acid attached to the tRNA anticodon.  Write the name of the amino acid translated from the mRNA decoder in the first box below, using the chart provided.
4. Match the next 3 mRNA codons with 3 tRNA anticodons, Again determine the amino acid attached to the tRNA anticodon using the mRNA decoder and write it in the second box below.
5. Repeat steps 4 and 5 for the rest of the mRNA molecule

7.  Draw a horizontal line between each amino acid.  Use your text to find the name of this bond.   Record your answer here:

The result of this bonding is a polypeptide, also known as a protein.

RNA, Transcription, and Translation Review

1. Carefully read each term or phrase in the left-hand column of the following table.  If the term or phrase applies to DNA, place a checkmark in the column labeled DNA.  If it applies to RNA, place a checkmark in the column labeled RNA.  If it applies to both nucleic acids, place a checkmark in both columns.

2. Write the corresponding mRNA sequence under the given DNA strand.

DNA:    A        T        G        C        T        A        A        C        G        T        C        A

mRNA:

3. Decide if each statement describes messenger RNA (mRNA), transfer RNA (tRNA), or ribosomal RNA (rRNA). There might be more than one answer for each problem.

1. _______________ Brings amino acids to the ribosome in the correct order to build new proteins .
2. _______________ Makes up the ribosome with other proteins
3. _______________Carries instructions for protein synthesis and is made by using DNA as         a template
4. _______________ Is made in the nucleus, and then leaves
5. _______________ Found in the cytoplasm.

Use the Codon Chart to answer the following questions:

4.  Given the following DNA codons, find the corresponding mRNA codon, the corresponding tRNA anticodon, and then find the amino acid.  ***Remember: Only look up the mRNA CODON in the chart, not the tRNA ANTICODON!***

5. Complete the following table with the given information.  You may have to work backwards.  The first row has been completed to help you get started.