PCR uses less space
DNA + enzymes more compact than whole cells
No growth medium required
In vivo requires many plates to be stored/incubated/refrigerated
PCR safer
Uses DNA & enzymes
Does not use whole cells which could cause contamination
PCR can use lower quality DNA
Can use old prehistoric/forensic DNA
PCR less labour intensive/easier
Set to run and left
Gene identified & cloned in one stage
In vivo requires more purification at end
In vivo less prone to mutation
Taq polymerase occasionally inserts wrong base
Early mutation reproduced many times in PCR
Exact correct sequence needed for making therapeutic proteins
In vivo less expensive
PCR primers/Taq polymerase/high temperatures expensive
Materials for growing bacteria cheap
In vivo less technically complex
Conditions not so critical
Optimising PCR takes time
In vivo useful when gene less well known/as longer piece of DNA can be cloned
Searching for new gene
Obtains complete gene
o PCR has limited size
6.2.1. Cloning and Biotechnology
Biotechnology is the industrial use of living organisms (or parts of living organisms) to produce food, drugs or useful
enzymes
Microorganisms are often used in biotechnological processes;
Fast growth
Large amount of product
Can be genetically engineered
o Avoids problem with side effects/allergic effects
Process can occur at low temperatures/pressures
o Low temperatures cheaper/safer to maintain
Products are pure so are easier to separate
Can grow on unwanted food
Ethical advanages
Rate of growth of population slows:
One or more of nutrients are
beginning to run out
Birth rate =Death rate
Nutrients run out
Organisms adjust to Increased levels of
surrounding conditions. toxic waste products
Taking in water, Death rate > Birth rate
cell expansion,
, Number of bacteria increase rapidly.
Cells growing/dividing at their maximum rate
for the particular conditions they are in
Length depends on how quickly organisms:
o Reproduce
o Take up nutrients
How can enzymes be immobilised;
Adsorbtion:
Bound to porous clay/carbon/resin/glass
Hydrophobic interactions/ionic links
o Not very strong, enzymes becomes detached - LEAKAGE
o Can give high reaction rates
Covalent Bonding:
Enzymes covalently bonded
Cross linking enzymes to each other and to clay
(using glutaraldehyde)
o Does not immobilise large quantity of enzyme
o Binding very strong - LOW LEAKAGE
Entrapment:
Enzymes trapped in alginate beads/cellulose network
Trapped in NATURAL STATE (not bound to another molecule/active site
unaffected)
o Reaction rate reduced
o Substrate molecules need to get through trapping barrier
Membrane separation:
Enzymes and substrate either side of partially
permeable membrane
Enzyme solution on one side of membrane, substrate
solution passed on other side
o Substrate molecules small enough to pass
through membrane so reaction can take place
o Product molecules small enough to pass back
through membrane
Method depends on:
Ease of preparation
Cost
DNA + enzymes more compact than whole cells
No growth medium required
In vivo requires many plates to be stored/incubated/refrigerated
PCR safer
Uses DNA & enzymes
Does not use whole cells which could cause contamination
PCR can use lower quality DNA
Can use old prehistoric/forensic DNA
PCR less labour intensive/easier
Set to run and left
Gene identified & cloned in one stage
In vivo requires more purification at end
In vivo less prone to mutation
Taq polymerase occasionally inserts wrong base
Early mutation reproduced many times in PCR
Exact correct sequence needed for making therapeutic proteins
In vivo less expensive
PCR primers/Taq polymerase/high temperatures expensive
Materials for growing bacteria cheap
In vivo less technically complex
Conditions not so critical
Optimising PCR takes time
In vivo useful when gene less well known/as longer piece of DNA can be cloned
Searching for new gene
Obtains complete gene
o PCR has limited size
6.2.1. Cloning and Biotechnology
Biotechnology is the industrial use of living organisms (or parts of living organisms) to produce food, drugs or useful
enzymes
Microorganisms are often used in biotechnological processes;
Fast growth
Large amount of product
Can be genetically engineered
o Avoids problem with side effects/allergic effects
Process can occur at low temperatures/pressures
o Low temperatures cheaper/safer to maintain
Products are pure so are easier to separate
Can grow on unwanted food
Ethical advanages
Rate of growth of population slows:
One or more of nutrients are
beginning to run out
Birth rate =Death rate
Nutrients run out
Organisms adjust to Increased levels of
surrounding conditions. toxic waste products
Taking in water, Death rate > Birth rate
cell expansion,
, Number of bacteria increase rapidly.
Cells growing/dividing at their maximum rate
for the particular conditions they are in
Length depends on how quickly organisms:
o Reproduce
o Take up nutrients
How can enzymes be immobilised;
Adsorbtion:
Bound to porous clay/carbon/resin/glass
Hydrophobic interactions/ionic links
o Not very strong, enzymes becomes detached - LEAKAGE
o Can give high reaction rates
Covalent Bonding:
Enzymes covalently bonded
Cross linking enzymes to each other and to clay
(using glutaraldehyde)
o Does not immobilise large quantity of enzyme
o Binding very strong - LOW LEAKAGE
Entrapment:
Enzymes trapped in alginate beads/cellulose network
Trapped in NATURAL STATE (not bound to another molecule/active site
unaffected)
o Reaction rate reduced
o Substrate molecules need to get through trapping barrier
Membrane separation:
Enzymes and substrate either side of partially
permeable membrane
Enzyme solution on one side of membrane, substrate
solution passed on other side
o Substrate molecules small enough to pass
through membrane so reaction can take place
o Product molecules small enough to pass back
through membrane
Method depends on:
Ease of preparation
Cost
