Q.17 The activity of an enzyme is expressed in International Units (IU). However, the S.I. unit for enzyme activity is Katal. One Katal is
Katal vs IU Enzyme Activity: 1 Katal Equals 6 × 107 IU
Correct Answer
One katal equals 6 × 107 IU (option C). Calculation:
1 kat = 1 mol/s = 106 μmol/s (since 1 mol = 106 μmol).
Per minute: 106 μmol/s × 60 s/min = 6 × 107 μmol/min = 6 × 107 IU.
This massive factor reflects katal’s scale for high-throughput enzyme kinetics in fermentation studies.
Option Explanations
- 1.66 × 104 IU (A): Underestimates by ~103; approximates 1 kat ≈ 16.67 μmol/min if miscalculating seconds only (ignores μmol scaling).
- 60 IU (B): Basic s/min conversion without molar adjustments; equates 1 mol/s to 60 μmol/min erroneously.
- 6 × 107 IU (C): Precise: (106 μmol/mol × 60 s/min) yields exact SI-to-IU factor used in clinical biochemistry labs.
- 106 IU (D): Captures μmol scaling alone (1 mol/s = 106 μmol/s) but omits 60-fold minute adjustment.
Biotech Applications
In microbial enzyme production, katal standardizes kinetic parameters (kcat) for bioengineering, while IU suits diagnostic kits. Jaipur-based fermentation research converts IU/mg protein to kat for global publications, enhancing SEO visibility in enzyme optimization workflows.
