ENZYMOLOGY
Course code:
MBC7103
Course Level:
1
Course Credit:
3 CU
Brief Course Description
This course begins with the Extraction and purification of enzymes, Enzyme activity, Factors
affecting enzyme activity, enzyme inhibition. Enzyme kinetics: Multisubstrate enzyme
mechanisms (Chance mechanisms, Ping-pong mechanisms, Random sequential and ordered BiBi mechanisms).Mechanisms in families of enzymes (Serine proteases, Dehydrogenases,
Carboxypeptides, Lysozyme), Multisite and Allosteric enzymes (Non-cooperative sites,
Cooperative binding in allosteric enzymes, the Hill equation for Allosteric enzymes,
Sigmoidicity of velocity curves) Enzyme regulation and stability, Fine control of enzyme activity
(Steady state fluxes, and flux regulation by feedback, Saturated or substrate independent
reactions, Kacser and Burns theory, switch mechanisms, role of near equilibrium reactions in
maintaining metabolite concentrations).Finally the course ends up with measurement of enzyme
rate constants (Rapid mixing and sampling technique and Relaxation methods).
Course Objectives
At the end of this course learners should be able to:
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Explain the methods of extraction and purification of enzymes.
Explain the standardized reporting of enzyme activities (International units, katals,
turnover number)
Describe factors that affect enzyme activities and types of enzyme inhibitions
Describe enzyme kinetics of multisubstrate enzyme mechanisms
Explain enzyme reaction mechanisms used in selected families of enzymes.
Explain the binding of substrates to multisite and allosteric enzymes
Explain enzyme fine regulation and stability.
Describe the theories of Kacsaer and Burns, Switch mechanisms and near equilibrium
reactions.
Describe methods used in measuring enzyme rate constants.
Course outline
Extraction and purification methods for enzymes
(4 hours)
Description of available extraction and purification methods, and show how specific activities
of enzymes. The objective of each step is to retain as much enzyme as possible while getting rid
of unwanted contaminants. The efficiency of each step is given by yield and increase in specific
activity.
Factors that affect rates of enzyme activities and types of enzyme inhibitions (8 hours)
Detailed explanation of factors that affect rates of enzyme activities, fine control of enzyme
activities such as steady state fluxes, flux regulation by feedback, enzyme kinetics involving
multisubstrate enzyme mechanisms involving random sequential mechanism, ordered BiBi
reaction mechanisms, Ping Pong kinetic mechanism and Theorell-Chance mechanism
Enzyme reaction mechanisms used in selected families of enzymes
(8 hours)
Detailed description of enzyme reaction mechanisms used by Serine proteases, Dehydrogenases,
Carboxy peptidases and Lysozymes. Binding of substrates to multisite and allosteric enzymes
involving cooperative and non-cooperative sites, and Hill equation for allosteric enzymes and
sigmoidicity of velocity curves.
The theories of Kacsaer and Burns, Switch mechanisms and
Near equilibrium reactions
(5 hours)
The theories of Kacser and Burns, switch mechanisms and near equilibrium reactions will be
explained. The principles learnt in the mechanisms are explained in rapid mixing and relaxation
methods used in measuring enzyme rate constants.
Tutorials
(10 hours)
Practical
(30 hours)
Mode of course delivery
This course will be conducted in four main ways namely: Structured lectures, Coursework,
practical, and Tutorials.
Assessment
The following instruments (Test, presentations and examination) will be used to assess the
students. Their relative contribution to the final grade is shown below:
Requirement
Progressive (Practicals and assignments)
Tests
Final examination
Total
Contribution
20 %
20 %
60 %
100 %
Reading List
i)
The reading list includes but not limited to the following textbooks.
Lehninger ,A.L, Nelson, D.L., and Cox, M.M. (1993) Principles of Biochemistry 2nd
Edition. Worth Publishers, New York.
ii)
Stryer, L (2005) Biochemistry. 5th Edition. W.H. Freeman and Co. New York