Subtopic: Fundamentals of Biomolecules, enzyme kinetics
Question Statement:
Which of the following statements with respect to the orientation of the nitrogenous bases to the
pentose sugars, and the puckering of the sugar, is correct?
(A) Anti, and 2'-endo in A form DNA (B) Anti, and 2'-endo in B form DNA
(C) Syn, and 3'-endo in A form DNA
(D) Syn, and 3' -endo in B form DNA
Options:
(A) Anti, and 2'-endo in A form DNA
(B) Anti, and 2'-endo in B form DNA
(C) Syn, and 3'-endo in A form DNA
(D) Syn, and 3' -endo in B form DNA
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2014 Q.52)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **MCQ** (2 Marks)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Systematic Conceptual & Option-by-Option Evaluation**:
- Problem Focus: *"The percentage SIMILARITIES and IDENTITIES, respectively, between the two peptide
sequences given below will be ______% and _____%.
Peptide I : Ala-Ala-Arg-Arg-Gln-Trp-Leu-Thr-Phe-Thr-Lys-Ile-Met-Ser-Glu
Peptide II:..."*
- **Option (A) [CORRECT]**: *"80, 80"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (B) [INCORRECT]**: *"80, 60"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"60, 60"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"90, 60"* does not satisfy the precise boundary conditions or molecular specificity.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **A**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.66 marks).
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