Question

13. Draw the CK kinetic reaction curve by plotting the ABS values on the y-axis, a the time 30 seconds) x-axis. (example: 1.080 ABs seconds, 1.080 ABs at 30 seconds, 1.085 at 60 seconds, 1.090 at 90 seconds, etc) Label the lag, linear and substrate depletion phases. Note: The linear ABS values you chose in step 12c should correlate with the most linear section of the linear phase of the reaction on this kinetic curve. You should be able to evaluate the ABS readings and determine the presence or absence oflinearity.... And what we need to do if the reaction is not linear. We measure enzyme activity in the linear phase of the reaction (when rate of product formation is constant) CLS 414 Clinical Chemistry Rotation I Unit 2 Module: Enzyme Kinetics WORKSHEET: Double Beam Spectrophotometer Time Scan Determining Enzyme Activity: Creatine Kinase (CK) TIME SCAN: CK UNKNOWN: Clyde Smythe ABS A ABS 30 sec A ABS/min nterval seconds) 1.080 1.080 30 1.085 1.090 120 1.090 1.095 150 180 1.090 1.099 210 1.289 330 .434 1.582 1.736 889 420 2,044 480 510 2.348 540 2,378 2.388 2.393 2.403 630 2.411 2.42 2.425 2.430

Answer 1

1.080-1.099 is the lag phase as the absorbance is slowly increasing with time

1.119- 2.425 is the linear or in other words the exponential phase. Here , the absorbance is proportionately increasing with respect to time .

2.430-2.412 is the substrate depletion phase. Here, even with increase in time , the absorbance has started reducing.

Looking at the readings it can be estimated that the linearity is being followed. Substrate formation is constant in the linear phase.