Bio 30 DNA and Protein Synthesis Assignment Name: COMPLIMENTARY DNA 1. Record the complementary DNA bases Complementary DNA bases (green) White DNA template A C C T A T GC C A C C T 2. G G A T A C G G T G G Please replicated the DNA molecule below into TWO identical sister chromatids attached with a centromere. TCGATATCGG Template AGCTATAGCC TCGATATCGG AGCTATAGCC Template PROTEIN SYNTHESIS 3. Fill in the box below with the complementary mRNA nucleotide to the DNA template nucleotide: DNA A T C G mRNA U A G C Using the same White DNA template, write the complete mRNA sequence (red nucleotides only) that is transcribed below (include the white DNA template): Red mRNA codon bases White DNA template 4. A T 5. C C U G G A A T U G C C A C C A C G G T G G What do codons code for? Codons code for amino acids, or a signal to stop protein translation 6. List the correct mRNA codons (separated into groups of three) sequence below for your transcribed mRNA from above: ACC UAU GCC ACC 7. Which RNA molecule has the anti-codons? tRNA, or transfer RNA has anti codons that are complementary to mRNA codons. 8. What else can be found attached to the molecule from the prior question? Amino acids 9. What is the function for the anti-codons? Attaches to a complementary mRNA codon so the correct amino acid is in that spot. 10. Using the video, the whiteboard images and the answers from your prior questions, list the DNA template again along with corresponding mRNA codon and the correct anti-codon bases (they’re on the cups): Anti-codon bases from tRNA cups Red mRNA codon bases White DNA template UGG A U A CGGUGG C C U G G A A T A T U G C C A C C A C G G T G G 11. The anti-codons from each tRNA cup, in groups of 3 are complementary to the mRNA codons. Each tRNA will bring in the correct amino acid. List the four amino acids that was brought in to make the final protein. Thr - Tyr - Ala - Thr 12. If we were meeting, you would be asked to assess the characteristic of your “protein” – What does it taste like? From the lecture video, what did it taste like? Sugar and sweet Changes in the DNA sequence that alters the outcome of protein synthesis are called mutations. Advantageous mutations may lead to improved or new (novel) proteins (like COVID-19) that enhance survival of an organism (although SARS CoV-2 is not an actual organism – remember the seven characteristics of life?). Disastrous mutations most often lead to death for an organism. Silent mutation may not have any noticeable effect on the protein structure, thus there is no effect on the actual organism. You will learn, or may have learned, that mutations are the raw material for natural selection. Some environmental condition in nature will be the ultimate judge of whether the mutations are considered favorable or not. In the following several questions, you will examine so mutations. 13. Suppose the 5th base pair (from the left) of the original DNA template is changed from “T” to “A. a. How does this affect the mRNA sequence? Write the new mRNA sequence below: Red mRNA codon bases White DNA template b. Can you notice a difference between this protein and the first one? If we were meeting, you would be asked to assess the characteristic of your “protein” – What does it taste like? From the lecture video, what did it taste like? A T C C U U U G G A A A It tasted salty instead of sweet :0 G C C A C C C G G T G G 14. Suppose the original DNA is changed so that the 11th base pair (from the left) is no longer “G” but becomes “C”. a. How does this affect the mRNA sequence? Write the new mRNA sequence below: Red mRNA codon bases White DNA template b. Can you notice a difference between this protein and the first one? If we were meeting, you would be asked to assess the characteristic of your “protein” – What does it taste like? From the lecture video, what did it taste like? A T C C U A G G A T U G C C A A C G G T G C C G Now it is VERY sugary 15. If you were to try the three proteins, which do you think would taste the best and why? Definitely the first one because it is sweet but not too sweet 16. In nature, what is the ultimate judge of the “better” or the “worse” protein? In nature, the environment is the ultimate judge of a "better" or "worse" protein. A good mutation will lead to more offspring and a bad mutation will lead to less offspring 17. What are the consequence(s) of “better” or “worse” to individuals and the population? A "better" protein will lead to an individual becoming more fit: it will better survive and reproduce. Over time, as the mutation is passed on, the population will become more fit. Let’s say we had additional tRNA cups in our experiment with other possible anticodon combinations, each containing yet another ingredient… 18. a) Consider what would happen to the product in your experiment if base #4 (from the left) was DELETED from the original DNA. Write the new sequence mRNA sequence: C C A U G C C A C C Red mRNA bases A White DNA template T b) G G T A C G G T G G How many mRNA codons are present now? Does this mRNA have any similarities/differences with the original four mRNA codons? There are only three codons present now. This frameshift deletion will change all the amino acids, except the first one. 19. What might the overall effect of the 4th DNA base (from the left) deletion, described in the previous question, be on the final product produced – would it have the same function as the original protein? The new protein will not have the same function. It will go from Thr - Tyr - Ala- Thr to Thr - Met Pro. Not only will it have less amino acids, three of the amino acids will also be different.
