CE 10079 - Bioprocess Engineering Fundamentals Flashcards Preview

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Flashcards in CE 10079 - Bioprocess Engineering Fundamentals Deck (112)
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What are intensive properties?

Properties independent of the size of a system.

E.g. concentration, temperature, velocity, pressure.


What are extensive properties?

Properties which depend on the size of a system.

E.g. volume, flow rate, mass, energy, force.


What’s bioengineering?

The application of the various branches of engineering, including mechanical, electrical, and chemical engineering to biological systems.


What are the typical elements of bioengineered reactor systems?

Influent (flowing in)
Effluent (flowing out)
Aeration processes


What’s a model?

It is a experimental nor mathematical tool to make predictions on the behavior of real systems subject to different disturbances.

It helps us to improve our understanding of the behavior of reality.
It’s analysis is more effective than direct observation of reality.


What’s a simulation?

A simulation implements a model of a system.

It allows us to perform virtual (non physical) experiments and to arrive at results, which
are transferable to reality.


What is advection?

The transfer of heat or matter by the flow of a fluid, especially horizontally in the atmosphere or the sea.

[If you have silt suspended in the water and heat it then you will get convection of the water and advection of the silt.]


What dispersion?

Advection averaged over space.


What’s sedimentation?

Directed movement relative to water.

The process of settling or being deposited as a sediment.


What’s turbulent diffusion?

Turbulent diffusion is the transport of mass, heat, or momentum within a system due to random and chaotic time dependent motions.

Turbulent diffusion or dispersion is the process by which a substance is moved from one place to another under the action of random turbulent fluctuations in the flow.


What are the 3 classifications of lipids?

Simple (fats and oils / triglycerides)

Compound (phospholipids and glycolipids)

Derived (steroids/cholesterols and carotenoids)


What are fatty acids?

Molecules which form fats and oils, consisting of a hydrophobic hydrocarbon tail and a hydrophilic carboxyl head.

They can be saturated and unsaturated.


What are triglycerides?

Molecules of glycerol and 3 fatty acids (bonded by ester bonds).


What are micelles?

Aggregates, composed of single tail lipids with hydrophilic heads and hydrophobic tails.

Their centres are usually hydrophobic also.

They form when critical micelle concentration (CMC) is reached.


How is micelle shape parameter calculated?

Ns = V / AL

Ns is shape parameter
V is volume of the tail
A is area of the head
L is max length of the tail


How is the Gibbs energy of micellization calculated?

ΔG micelle =RTln(CMC)

- ΔG is Gibbs energy of micellization
- R is universal gas constant
- T is the minimum temperature micelle forms
- CMC is critical micelle concentration (in M)


What are phospholipids?

Molecules which generally consist of two hydrophobic (nonpolar) fatty acid "tails" and a hydrophilic (polar) phosphate "head", joined together by a glycerol molecule.


What are liposomes?

A spherical vesicle composed of phospholipids.

They often have hydrophilic centres.


What are the 2 means of liposome or micelle uptake by cells?


Receptor mediated endocytosis (RME)


How are liposomes and micelle taken up by the cell via phagocytosis?

They’re engulfed by the cell.
The cell surrounded the molecule then forms a vesicles around it.


How are liposomes and micelles taken up by cells via receptor mediated endocytosis (RME)?

The liposomes or micelles bind to receptors on the cell surface membrane, which are then engulfed and taken into vesicles.


What does K D represent? (D in subscript)

Dissociation constant (for binding between receptors and liposomes/ligands)


How is rate of association and rate of dissociation calculated (for when liposomes/micelles bind to receptors)?

Rf = kf [R] [L]
- Rf is rate of association
- kf is association rate constant
- [R] receptor conc'
- [L] is ligand (liposome) conc'

Rr = kr [C]
- Rr is dissociation constant
- kr is dissociation rate constant
- [C] is conc' of complexes / occupied receptors


How is K D (dissociation constant) calculated?

K D = [R] [L] / [C] = kr / kf


- kf is association rate constant
- kr is dissociation rate constant
- [R] receptor conc'
- [L] is ligand (liposome) conc'
- [C] is conc' of complexes / occupied receptors


How is the fraction of saturated / occupied receptors calculated?

r = [L] / [K D] + [L]

- [L] is ligand (liposome) conc'
- [K D] is dissociation constant


What's catabolism and anabolism?

Catabolism - the breaking down of molecules, which releases energy.

Anabolism - the synthesis of complex molecules.


What is the typical notation for substrates [in bioengineering]?

Readily biodegradable, growth-limiting substrate

S - soluble materials

X - particulate materials

Subscripts - denote material type


What does the substrate notation Ss represent (an example for chemoheterotrophs)?

S - it's a soluble molecule

s - it's a growth substrate

Used as e– donors and carbon (C) source.
Limiting means it is essential for heterotrophic growth and cell maintenance;  Examples: glucose, sucrose, fructose, maltose, or galactose, acetate.


What does the substrate notation So represent (an example for chemoheterotrophs)?

Terminal electron acceptors

Acronyms used:
S - soluble
o - oxygen
Used as terminal e– acceptor
They are growth limiting substrates.

Examples: oxygen, nitrate(SNO3), nitrite(SNO2), sulfate (SSO4).


What currency units are used in metabolic calculations?

- Electrons (e-) chemicals participating in redox reactions.

- Mass of N nitrogen containing chemicals (NH4+, NO3-, amino-acids) (N: 14 g/mol)

- Mass of P phosphate containing chemicals (e.g., PO43-, polyphosphate) (P: 31 g/mol)