In this chapter, we focused on the translation of mRNA into proteins as well as on protein...

In this chapter, we focused on the translation of mRNA into proteins as well as on protein structure and function. Along the way, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, what answers would you propose to the following fundamental questions:

(a) What experimentally derived information led to Holley’s proposal of the two-dimensional cloverleaf model of tRNA?

---

(b) What experimental information verifies that certain codons in mRNA specify chain termination during translation?

---

(c) How do we know, based on studies of Neurospora nutritional mutations, that one gene specifies one enzyme?

---

(d) On what basis have we concluded that proteins are the end products of genetic expression?

---

(e) What experimental information directly confirms that the genetic code, as shown in Figure, is correct?

---

(f) How do we know that the structure of a protein is intimately related to the function of that protein?

Figure

The coding dictionary. AUG encodes methionine, which initiates most polypeptide chains. All other amino acids except tryptophan, which is encoded only by UGG, are represented by two to six triplets. The triplets UAA, UAG, and UGA are termination signals and do not encode any amino acids.