this is biotechinology students

1. Fundamentals of Biochemical Engineering
(Biot4132)
By: Begashaw M (MSc.)
DEBRE BERHAN UNIVERSITY
Department of Biotechnology
October, 2019

2. Chapter 1
Fundamentals of Biochemical Engineering
2
1. Introduction
1.1. Metabolic Stoichiometry and Enzyme Kinetics
1.1.1. Metabolic Stoichiometry
 Molecular genetics (reading assignment)
 Metabolic energetic
1.1.2. Enzyme kinetics
 Substrate utilization
 Product formulation and biomass production
 Fermentation kinetics

3. 1. Introduction
 Overview of Biochemical Engineering
– Biochemical engineering, also known as bioprocess engineering, is a
field of study that deals with the design, construction, and
advancement of unit processes that involve biological organisms or
biomolecules
– It has various applications in areas such as biofuels, food, feed,
pharmaceuticals, biotechnology, and water treatment industries
– These processes use living cells or enzymes in biochemical reactors,
called “fermentors” to conduct the manufacturing
o biochemical engineering is concerned with conducting biological
processes on an industrial scale

4. Introduction………cont’d
 History of Biochemical Engineering
– For thousands of years, humans have made use of the chemical reactions
of biological organisms in order to create food products
e. g. Yogurt, Cheese, Wine and Beer
– The field of biochemical engineering was established since 1928 after
Alexander Fleming discovered penicillin
– After this discovery, biological processes are conducted in industrial scale
– For example, in early 20th century, pure bakers yeast were being produced
in tanks and sold
– In world war II, antibiotics production became on the commercial scale
– 1970s: therapeutic proteins and enzymes are produced using recombinant
DNA and cell fusion technologies

5. Biochemical engineering overview………..
 Microorganisms as production factory
– Microorganisms in the process of self replication, produce several
complex macromolecules from about 100 different monomer units
– To achieve this a bacterial cell uses well over 1000 different
enzymes and a eukaryotic cell may employ twice as many

6. Biochemical engineering overview………..
 Products of bioprocess technology
o Bioethanol, biobutanol, acetone, propane-diol, biodiesel (fat & oils)
o Organic acids (citric acid, lactic acid, succinic acid, amino acids)
o Pharmaceuticals (e.g. antibiotics, vaccines)
o Biopolymers (bioplastics and rheology)
o Proteins: enzymes and therapeutics
o Gene therapy products (packaged nucleic acid sequences)
o Microbial cells (environmental clean-up; waste treatment)
o Human cells (stem cells; tissue replacements)

7. 1.1. Metabolic Stoichiometry and Enzyme Kinetics
1.1.1. Metabolic Stoichiometry
– Metabolic stoichiometry is the study of the relationships between the
amounts of reactants and products of metabolic reactions
– It is the calculation of quantitative relationships between the amounts
of reactants used and amounts of products formed by metabolic
reactions
– Metabolism is essentially a large network of coupled chemical
conversions (reactions) catalyzed commonly by enzymes
– In this process, nutrients are converted into building blocks:
o nucleotides, fatty acids, amino acids, and free energy carriers
– Macromolecules (DNA, RNA, lipids and proteins) are synthesised
from building blocks
– Catabolic pathways provide energy for biosynthesis and reducing
equivalents for carbon reduction reactions

8. Metabolic Stoichiometry………cont’d
 Typical metabolic reaction (pathway) sizes
 up to ∼ 10 reactions
o single metabolic pathways (glycolysis, amino acid synthesis
pathways, and TCA cycle)
 10 – 100 reactions
o core network of carbon utilization
 100 – 2000 reactions
o large to genome scale metabolic networks of one microorganism
e.g. E. coli, Yeast etc.
 > 2000 reactions
o Global metabolic networks of higher organisms: human

9. Metabolic Stoichiometry………cont’d
– There are 3 types of stoichiometry in biological systems
a. Reaction stoichiometry - the number of each kind of atom involved
in a metabolic reaction
b. Obligate coupling stoichiometry - the required coupling of electron
carriers
c. Evolved coupling stoichiometry - the number of ATP molecules
that pathways have evolved to consume or produce

10. Metabolic Stoichiometry………cont’d
– Stoichiometry is based on the law of conservation of mass that states
“matter is neither created nor destroyed in a chemical reaction”
o applicable to all chemical reactions
– In any chemical reaction, the amount of matter present at the end of
the reaction is the same as the amount of matter present at the
beginning
i.e. the mass of the reactants equals the mass of the products
– A balanced chemical equation is used to describe a reaction’s
stoichiometry
– Because a chemical equation does not directly tell us anything about
the masses of the reactants and products

11. Metabolic Stoichiometry………cont’d
– However, by converting the known mole quantities to mass, the mass
relationships become obvious
– Coefficients from the equation are used to derive stoichiometric
factors that subsequently used for computations relating reactant and
product masses, molar amounts, and other quantitative properties
– The stoichiometric coefficient is the number written in front of atoms,
ions and molecules in a chemical reaction to balance the number of
each element on both the reactant and product sides of the equation
– Stoichiometric coefficients establish the mole ratio between reactants
and products

12. Metabolic Stoichiometry………cont’d
– In a balanced reaction, both sides of the equation have the same
number of elements
– Stoichiometric reaction balancing is a common task in metabolic
network reconstruction, wider metabolic modeling and indeed across
chemistry
– Usually stoichiometries are simple enough to calculate manually but
when undertaken at genome scale balancing becomes time
consuming, boring and wasteful of expert resource
– Automatic balancing tools are emerging like SuBliMinaL Toolbox and
others

13. Metabolic Stoichiometry………cont’d
 Fundamental aspects of any chemical equation:
1. The substances undergoing reaction are called reactants, and
their formulas are placed on the left side of the equation
2. The substances generated by the reaction are called products ,
and their formulas are placed on the right sight of the equation
3. Plus sign (+) separates reactants and products formulas, and an
arrow (⟶) separates the reactant and product sides of the
equation
4. The relative numbers of reactant and product species are
represented by coefficients

14. Stoichiometric calculations
– What tools are needed to perform stoichiometric calculations?
– The solution to every stoichiometric problem requires a balanced
chemical equation
– Mole ratios based on the balanced chemical equation are needed, as
well as mass-to-mole conversions
 Stoichiometry problem solving strategy
 Steps used to solve mole-to-mole, mole-to-mass, and mass-to-mass
stoichiometric problems
1. Write the balanced chemical equation for the reaction
– To determine where to start calculations, note the unit of the given
substance

15. Stoichiometric calculations……….
2. If mass (in grams) of the given substance is the starting unit, begin
your calculations by converting the mass of the given substance to
the corresponding number of moles using its molar mass
3. If amount (in moles) of the given substance is the starting unit, obtain
the number of moles of the required substance from the number of
moles of the given substance using the appropriate mole ratio from
the balanced chemical equation
4. Convert the number of moles of required substance to mass using its
molar mass

16. Stoichiometric calculations……….
 Example 1: how many moles of O2 react with 3 moles of H2?
 Solution
 Write and balance the chemical equation first
2H2 + O2 2H2O
 Drive the mole ratios
3 mol H2 X 1 mol O2
2 mol H2
 How many moles of H2O are produced from 2.4 moles of O2?
 Solution
o Follow same procedure as above
2.4 mol O2 X 2 mol H2O
1 mol O2
= 1.5 mol O2
= 4.8 mol H2O
Write the stoichiometric
equation
H2 + O2 H2O
Write the stoichiometric
equation
H2 + O2 H2O

17. Calculations……….
 Example 2: 10 grams of glucose (C6H12O6) react in a combustion reaction.
How many grams of each product are produced?
C6H12O6 + 6 O2  6 CO2 + 6 H2O
10g ?g + ?g
– Starting with 10g of C6H12O6, calculate the moles of C6H12O6
– Use the coefficients to find the moles of H2O and CO2 and then turn the
moles to grams
C6H12O6 + 6O2  6CO2 + 6H2O
Mass-------10g ?g + ?g
MW--------180g/mol 44g/mol 18g/mol
#mol-------10g/180g 6(0.055 mol) 6(.055mol)
= 0.055 mol = 0.33 mol = 0.33 mol
#grams------------------------------- (0.33mol)44g/mol (0.33mol)18g/mol
= 14.52g = 5.94g
Writethebalanced
stoichiometricequation

18. Calculations………..
 Example 2: how much ethanol can be obtained from the fermentation of
1kg of glucose?
C6H12O6 2C2H5OH + 2CO2
Mass -------------1000g -------------------?mol
MM---------------180g/mol ---------------46g/mol
#mol------------1000g/180g----------2(5.55mol)
= 5.55 mol = 11.10 mol
 What mass of CO2 is produced from animal metabolism of 1kg of glucose?
C6H12O6 + 6O2 6CO2 + 6H2O
Mass-----------------1000g----------------------?g
MM-------------------180g/mol------------------44g
#mol-----------------1000g/180g-------------6(5.55mol)
= 5.55 mol = 33.3 mol
#grams-------------------------------------33.3mol x 44g
=1465.2g
In all above examples, the
mass of reactants are equal
with mass of products (law
of conservation of mass)

19. Class work
Q1.Make one stoichiometric equation for metabolic pathway of
glycolysis, summarizing up from glucose to pyruvate