Biology181 i need complete asap | Biology homework help
- Based on your answer to Question 32, why do the three selected amino acids in the antagonistic
peptide fail to bind to Receptor 1 (R1)? Step 3: Use a genetic code to design a sequence of DNA coding for a peptide or protein that binds only to receptors in tumor cells. Thanks to your careful analysis, we know which amino acids are needed to create a peptide or protein that binds to R2 but not R1. We can use this information to synthesize many molecules targeting the tumor cells in spotted gliders. If we use an antagonistic peptide or an oncolytic virus to treat cancer, we must synthesize these molecules in the lab by using DNA to code for the necessary amino acid sequences. Proteins are artificially produced by transcribing DNA into mRNA and translating mRNA into amino acids, but selecting the correct DNA sequence is crucial to ensure the treatment targets only the tumor receptors (R2) and not normal cells (R1). To determine the correct DNA sequence, we must use the genetic code of Phygaris, which differs from Earth's genetic code. While Earth's DNA consists of adenine (A), thymine (T), cytosine (C), and guanine (G), Phygaris DNA uses cytosine (C), guanine (G), xorine (X), and yolocine (Y) as its four nucleotides. Figure 9 compares Earth’s DNA with Phygaris DNA, showing their structural similarities and differences. Figure 9, long description Figure 9. A side-by-side comparison of the molecular structure of DNA on Earth versus Phygaris. Both structures have a double helix structure, with complementary strands of DNA running antiparallel to one another (5’ to 3’ on one end and 3’ to 5’ on the complementary strand). Both versions of DNA have a sugar-phosphate backbone with nucleotides hydrogen bonded in the middle of the double helix structure. Both structures have complementary base pairing between two pairs of nucleotides. In DNA found in organisms living on Earth, the nucleotide base pairs are (1) guanine (G) and cytosine (C) and (2) adenine (A) and thymine (T). In DNA found in organisms living on Phygaris, the nucleotide base pairs are (1) guanine (G) and cytosine (C) and (2) xorine (X) and yolocine (Y). On Phygaris, proteins are encoded by codons, which are sequences of three nucleotides that specify particular amino acids. The genetic code of Phygaris contains 64 codons, 61 of which correspond to the 21 amino acids used by spotted gliders. For example, the codon YCX codes for threonine, while GCX
codes for norvaline. Figure 10 shows how to read the codon chart:
Figure 10, long description Figure 10. The genetic code of Phygaris consists of 64 codons representing 21 amino acids. ● The first base is found in the leftmost column. ● The second base is in the top row. ● The third base is in the rightmost column. ● The intersection of these positions determines the amino acid. To practice, let’s consider the amino acid proline. According to the genetic code, proline is encoded by CCX, CCC, CCY, and CCG (highlighted in Figure 11). Once you understand this example, you can identify the correct codons needed to synthesize a peptide that binds to R2 but not R1. Figure 11, long description Figure 11. Four codons represent proline in the genetic code of Phygaris: CCX, CCC, CCY, and CCG. These codons are highlighted in the red box. Use Table 1 to help you simplify your task. First, enter the three amino acids needed for a molecule to bind to the receptors of tumor cells; these amino acids are listed in your answer to Question 32. Then, enter all codons in the genetic code of Phygaris that correspond to each of the three amino acids. Directions: For questions 35-37, use the workbook and refer to the sheet titled “Q26-37 Amino Acids Help.” You can use Table 1 above to fill in the correct amino acids and their respective codons. This table is also found on tab “Q26-37 Amino Acids Help” if this is more convenient for you.