NEET Calculation Templates for Biomolecules

Template 1 — Chargaff Calculations:

Given: [A] = x% Then: [T] = x% (by Chargaff) Therefore: [G] = [C] = (100 - 2x)/2%

Example: [A] = 30% → [T] = 30% → [G] = [C] = (100-60)/2 = 20%

Template 2 — Hydrogen Bond Count:

$\text{Total H-bonds} = (\text{number of A-T pairs} \times 2) + (\text{number of G-C pairs} \times 3)$

Example: 500 A-T pairs + 300 G-C pairs → H-bonds = 500×2 + 300×3 = 1000 + 900 = 1900

Template 3 — Peptide Bond Counting:

$\text{Peptide bonds in chain} = n - 1 \quad \text{(where n = number of amino acids)}$

$\text{H}_2\text{O molecules released during synthesis} = n - 1$

$\text{H}_2\text{O molecules consumed during hydrolysis} = n - 1$

Template 4 — From base pairs to nucleotide counts:

For DNA with N base pairs:

• Total nucleotides = 2N
• If [G-C] = p%, then G-C pairs = pN/100; A-T pairs = (1-p/100)N
• Total nucleotides: G = C = pN/100; A = T = (1-p/100)N

Template 5 — Water released in polysaccharide formation:

$\text{H}_2\text{O released} = n - 1 \quad \text{(where n = monosaccharide units)}$

For starch with 1000 glucose units: 999 glycosidic bonds, 999 $H_{2}O$ released.