46. If the chemical composition of proteins in an organism is CH1.5O0.3N0.3S0.004, the mass percentage of
carbon in the proteins is __________.
Calculation Method
To find the mass percentage of carbon, treat the formula as representing 1 mole of protein units. Calculate the mass contribution of each element using atomic masses (C: 12, H: 1, O: 16, N: 14, S: 32), then divide carbon’s mass by the total molar mass and multiply by 100.
- Mass of C: 1×12 = 12
- Mass of H: 1.5×1 = 1.5
- Mass of O: 0.3×16 = 4.8
- Mass of N: 0.3×14 = 4.2
- Mass of S: 0.004×32 = 0.128
Total molar mass: 12 + 1.5 + 4.8 + 4.2 + 0.128 = 22.628
Carbon percentage: (12 / 22.628) × 100 ≈ 53.0%
Step-by-Step Breakdown
Assume 100 g of protein for simplicity, scaling atoms proportionally, but the molar ratio method above is equivalent and precise. No multiple-choice options appear in the query, so the focus remains on this direct computation, which aligns with empirical formulas in protein composition analysis.
Introduction
Proteins serve as fundamental biomolecules in organisms, and understanding the mass percentage of carbon in proteins with the empirical formula CH1.5O0.3N0.3S0.004 is crucial for students in molecular biology, genetics, and biochemical engineering. This calculation reveals carbon constitutes about 53% of the protein’s mass, reflecting its backbone role in amino acids.
Why Calculate Elemental Composition?
In biotechnology and microbial biotechnology, such formulas approximate average protein makeup, aiding fermentation process design and bioreactor scaling. Carbon’s high percentage underscores its dominance, typically 50-55% in proteins.
Detailed Solution for Exams
Follow these steps for mass percentage calculation:
- Compute each element’s mass using atomic weights.
- Sum for total molar mass (22.628 u).
- Carbon % = (12 / 22.628) × 100 = 53.0%.
This matches GATE biotechnology practice questions and verifies typical protein compositions.
