# DBT JRF 2020 — Question 58

Exam: DBT JRF 2020 · Section: B · Topic: Molecular Biology · Difficulty: Medium

## Question

In the cloverleaf structure of tRNA, the cognate amino acid is attached at

## Options

- **A.** acceptor stem
- **B.** T loop
- **C.** D loop
- **D.** anticodon arm

## Answer

Option A

## Explanation

Computational protein structure prediction rests on three foundational assumptions: (1) Thermodynamic hypothesis (Anfinsen, 1973): the native folded state corresponds to the global minimum of Gibbs free energy for the given amino acid sequence under physiological conditions — $\Delta G_{\text{unfolded} \rightarrow \text{folded}} < 0$ . (2) Monomeric folding: each polypeptide chain folds independently from its own sequence (applicable to single-domain proteins; chaperone-assisted folding modifies but doesn't contradict this). (3) Reliable potential energy functions: force fields (AMBER, CHARMM, OPLS) can reasonably approximate the contributions of bond stretching, angle bending, torsional potentials, electrostatics (Coulomb), and van der Waals forces to determine the lowest-energy conformation. AlphaFold2 has transformed the field by achieving near-experimental accuracy using deep learning.

Source: https://mypyqbuddy.com/questions/in-the-cloverleaf-structure-of-trna-the-cognate-6a05a8a02adafec470293252