1) This activity demonstrates how DNA controls the synthesis of proteins. Proteins are made up of a chain of amino acids. You are to determine the original DNA code for part of a hemoglobin protein molecule, especially for the 3 amino acid chain of: threonine – proline - glutamate.
Procedure:
Write out the codon for each amino acid as used in the text and previous question. Label this set of 3 codons as mRNA. Above this mRNA, write out the corresponding DNA. This is the “sense strand”. Above the “sense strand”, write out the corresponding “anti-sense strand”. (The other side of helix can also be called the compliment.) For this online question, you only need to fill in the three blanks for these three lines. Label and record the three lines of letters. Write out your answers on a scrap piece of paper and keep for the following questions. 3 marks
______ → DNA anti-sense strand codons
______ → DNA sense-strand codons
______ → mRNA original strand codons
2)
Construct the three tRNA anticodons and record it in the answer field. Use your answers from the previous question. On your scrap piece of paper, place the tRNA below the codons from the previous question. 1 mark
________→ tRNA anticodon
3) Messenger RNA (mRNA) is a single-stranded molecule that passes through nuclear pores into the cytoplasm to ribosomes situated on the endoplasmic reticulum. The triplet codons are read from mRNA as it passes through the ribosome. The function of tRNA is like that of a wheelbarrow as it brings the correct amino acid to the work site at the ribosome for protein synthesis.
Complete the following blanks with the correct terms.
A tRNA (UGA) carries as its load, only the amino acid called _______ . It plugs into the ribosome because _____ , (UGA), matches the mRNA codon ______.
(letters)
A different tRNA (GGG) carries only the amino acid _______ and ______ , (GGG), which allows it to match the mRNA codon ______.
Another tRNA (CUU) carries the amino acid ______ and its anticodon (CUU), which allows it to match the mRNA codon _____.
Note: Each of these three lines have a similar type of answer for each location. Use this information to help you fill in the answer. For example, The last blank for each line is going to be a three letter code. 4 marks