Previous Year Question Analysis

Pattern 1: Enzyme Action on Activation Energy (Most Frequent)

Question type: "Enzymes lower the _____ of a reaction."
Trap options: Free energy change, equilibrium constant, enthalpy change, activation energy
Correct answer: Activation energy
Why tested: Students confuse kinetic (activation energy) and thermodynamic ( $\Delta G$ , Keq) properties
Frequency: Appears in almost every NEET paper since 2010 in some form

Pattern 2: Ribozymes — "Not all enzymes are proteins"

Question type: "Which of the following is NOT a protein?" Options: Trypsin, Collagen, Ribozyme, Insulin
Correct answer: Ribozyme (it is RNA)
Frequency: High — appears in 60% of NEET papers; one of the most predictable traps

Pattern 3: Polysaccharide Linkages

Question type: "Which polysaccharide uses beta-glycosidic bonds?"
Correct answers: Cellulose, Chitin
Common trap: Students confuse glycogen (alpha) with cellulose (beta)
Frequency: Moderate — appears 2-3 times per decade in direct or indirect form

Pattern 4: Competitive vs. Non-Competitive Inhibition

Question type: "Malonate inhibits succinate dehydrogenase — what type of inhibition?" or "In competitive inhibition, Km _____ and Vmax _____."
Key answer: Competitive: Km increases, Vmax unchanged. Non-competitive: Km unchanged, Vmax decreases.
Frequency: High — appears regularly in kinetics and inhibition questions

Pattern 5: Disaccharide Composition

Pattern 6: Haemoglobin as Quaternary Structure

Question type: "Which protein has quaternary structure?" or "How many subunits does haemoglobin have?"
Key facts: 4 subunits (2α + 2β), quaternary structure, prosthetic group = haem
Frequency: Regular

Strategy for PYQ-Based Preparation: