For each type of tRNA, there is a specific enzyme that recognizes the anti-codon in the tRNA and attaches the correct amino acid for that anti-codon (step 2 in this figure). Translation takes place in ribosomes. Inside the ribosome, a codon in an mRNA molecule is matched by the base-pairing rules with an anti-codon in a tRNA (step 3). The tRNA brings the correct amino acid for that position in the protein molecule. Each amino acid is joined to the previous amino acid in the growing protein molecule (step 4). The ribosome moves along the mRNA, matching each codon with a complementary tRNA codon and adding the appropriate amino acids one at a time to produce the protein coded for by the mRNA. 11. In the figure, circle the anti-codon in a tRNA molecule that is not in the ribosome. - In the ribosome, put a rectangle around an anti-codon in a tRNA molecule and the complementary in the mRNA. 12. What part of translation depends on the base-pairing rules? Translation Modeling Procedure In this section you will simulate the steps in translation to produce the beginning of a hemoglobin protein. One of you will play the role of the ribosome and another will be the cytoplasm. Preparation: To model translation, you will need a page showing a ribosome, tRNA molecules, amino acids, the mRNA you made during your simulation of transcription, and a strip labeled "Second Part of mRNA". Tape the CUG end of the mRNA you made to the ACU end of the Second Part of mRNA strip. 13. For tRNA molecules to function in translation, each tRNA must be attached to the correct amino acid that corresponds to the anti-codon in that type of tRNA. To know which amino acid corresponds to each anti-codon in your tRNA molecules, use the base-pairing rules to complete this table. Amino acid Threonine Histidine Proline Leucine Glutamic acid Valine (Thr) (His) (Pro) (Leu) (Glu) (Val) Anti-codon in tRNA molecule that carries UGA this amino acid mRNA codon ACU CAU CCU CUG GAG GUG
For each type of tRNA, there is a specific enzyme that recognizes the anti-codon in the tRNA and attaches the correct amino acid for that anti-codon (step 2 in this figure). Translation takes place in ribosomes. Inside the ribosome, a codon in an mRNA molecule is matched by the base-pairing rules with an anti-codon in a tRNA (step 3). The tRNA brings the correct amino acid for that position in the protein molecule. Each amino acid is joined to the previous amino acid in the growing protein molecule (step 4). The ribosome moves along the mRNA, matching each codon with a complementary tRNA and adding the appropriate amino acids one at a time to produce the protein coded for by the mRNA. 11. In the figure, circle the anti-codon in a tRNA molecule that is not in the ribosome. - In the ribosome, put a rectangle around an anti-codon in a tRNA molecule and the complementary codon in the mRNA. 12. What part of translation depends on the base-pairing rules? Translation Modeling Procedure In this section you will simulate the steps in translation to produce the beginning of a hemoglobin protein. One of you will play the role of the ribosome and another will be the cytoplasm. Preparation: To model translation, you will need a page showing a ribosome, tRNA molecules, amino acids, the mRNA you made during your simulation of transcription, and a strip labeled "Second Part of mRNA". Tape the CUG end of the mRNA you made to the ACU end of the Second Part of mRNA strip. 13. For tRNA molecules to function in translation, each tRNA must be attached to the correct amino acid that corresponds to the anti-codon in that type of tRNA. To know which amino acid corresponds to each anti-codon in your tRNA molecules, use the base-pairing rules to complete this table. Amino acid Threonine (Thr) Histidine (His) Proline (Pro) Leucine (Leu) Glutamic acid (Glu) Valine (Val) Anti-codon in tRNA molecule that carries this amino acid UGA mRNA codon ACU CAU CCU CUG GAG GUG