Biochemical Engineering
Assignment on Enzyme Kinetics
Task 1
Using literature define the following with examples:
Biochemical Engineering; Biomolecular Engineering; Literature examples of each type of inhibitors for enzyme-catalysed reactions
Task 2
The substrate S is converted into product P by the catalytic action of the enzyme E.
Assuming the production P is governed by Michaelis-Menten kinetics, determine the maximum rate of reaction (Vmax) and Michaelis-Menten constant (KM) in the absence of any inhibitor (i.e. for [I] = 0) using all methods studied in the course.
Given the reaction rates in the presence of inhibitors, determine the type of inhibition that is most likely governing the kinetics of the inhibited production of P for inhibitor concentrations, along with kinetic parameters.
In a table, summarize your results and comment on the differences of values found from different methods.
In the form of bullet points, critically analyse your results and different methods, and report a single value for each parameter.
To improve the data fitting you may remove one or two outlier points. Provide bullet-point comments with your justification to remove data points if you do so, and comment if you do not need to do that. Finally, comment on the quality of fit.
Guidelines: The best way to obtain rate of reaction is to first fit the given data to a mathematical function as [S] =f(t) and then obtain rate of reaction as =−d[S]/dt. You may need to use Microsoft Excel Solver, Matlab or any other computation tool if you wish to do so. However, provide a full calculation detail to enable the verification of your calculations without writing your code.
30 Marks are allocated for this task. Determination of parameters have 20 marks, whereas 10 marks are devoted to general rigour, critical commentary, and ability to present results in an acceptable way.
Task 3
We want to develop an immobilized enzyme for an industrial application with the aim to minimize mass transfer limitations. We have the following laboratory results (see below). Determine the largest size of catalyst where the mass transfer limitation can be neglected.
In a lab experiment, 10 spherical particles of 8 mm diameter are coated with 0.018 kg enzyme/m3 of gel. The resulting solid is then used in a stirred tank with 3.2×10– 3kg/m3 substrate. The effective diffusivity of substrate in the gel is 2.1×10-9 m2/s. Kinetics of enzyme can be approximated as first order with specific rate constant 3.11 ×105/s per kg enzyme.
a). Determine the limiting regime (mass transfer limited, or reaction rate limited) transport. You can use the criteria stating that for all Thiele modulus ϕ > 3, diffusion is limiting regime instead of reaction.
b). If you must determine the maximum size of particles where diffusional resistance can be neglected, what approach will you use? Plot a graph including Thiele modulus and diameter of your particles. Identify sources of limitations of this approach.
Guidelines: Determine the amount of enzyme protein from readily calculable surface area of solids, then you need to pay attention to the unusual reaction rate in specific (per unit kg of enzyme) format. Finally, you can use the information of the first order to determine rate of reaction. Then you can use Thiele modulus for different bead sizes to see where the criterion is satisfied.
15 marks are equally distrusted in both parts.
We have included 10 data sets numbered from 0 to 9. Please match the last digit of your university ID number with the data set number and use that for your assignment. For example, for university ID number 59989710; dataset number 0 should be used as the ID number ends with 0.
Clearly write your university ID number on the front page and the dataset you took in your assignment. You must use only one data set.
