3′ end of t-RNA posseses ?
**Core Concept:**
The 3' end of t-RNA (transcriotionally-processed tRNA) contains a specific sequence that plays a crucial role in the proper folding and stability of the tRNA molecule. This sequence, called the "acceptor stem," is essential for the interaction with ribosomes, which are the cellular machines responsible for protein synthesis.
**Why the Correct Answer is Right:**
The correct answer is Option **C**: adenine (A). The 3' end of a tRNA molecule contains a purine base, which is responsible for stabilizing the structure of the molecule. Among the given options, adenine (A) is the correct choice because it is a purine base and contributes to tRNA stability and folding.
**Why Each Wrong Option is Incorrect:**
Option **A** is incorrect because it represents guanine (G), a pyrimidine base. Similar to adenine, guanine can stabilize tRNA structure, but the correct answer is A because adenine is the specific base present at the 3' end of tRNA.
Option **B** represents cytosine (C), another pyrimidine base. Like guanine, cytosine can also stabilize tRNA structure, but it is not the correct base present at the 3' end of tRNA.
Option **D** represents thymine (T), another pyrimidine base. As with C, T can stabilize tRNA structure, but it is not the correct base present at the 3' end of tRNA.
**Clinical Pearl:**
The 3' end of tRNA is crucial for its proper folding and interaction with ribosomes during protein synthesis. The presence of adenine ensures accurate amino acid selection by the ribosome and facilitates the correct folding of the tRNA molecule. This knowledge is essential for understanding tRNA's role in protein synthesis and cellular functions.