biology chpater 22 cloning and biotechnology

vegetative propagation:

• plant cuttings are taken and planted to give new shoots

• involves parts of the plants like bulbs, runners, rhizomes and stem tubers

• used in horticulture to make new plants cheaply

• the plants will be genetically identical

propagation from cuttings of stems is also much faster, and rooting powder is applied.

Natural cloning in plants

micropropagation:

• making large numbers of genetically identical offspring from a single parent plant using tissue culture

• take a sample of plant tissue

• sample is sterilised with beach or ethanol

• explant is placed in sterile culturing medium with plant hormones to stimulate mitosis, which forms a callus

• callus separated to medium to grow plantlets

artificial cloning in plants

advantages:

• rapid productin

• disease free plants

• large numbers

• reliably increase endangered plant numbers

disadvantages:

• produced monoculture

• expensive

• plantlets are vulnerable to disease

advantages and disadvantages of micropropagation

in invertebrates, starfish can clone parts of their body when cut off

vertebrates clone with twins in the womb

natural animal cloning

two types are twinning or somatic cell nuclear transfer

Twinning:

• Early embryos are artificially split

• used by farmers to produce maximum offspring from cows

Somatic cell nuclear transfer:

• nucleus is removed from a somatic cell of an animal and the nucleus from a different ovum

• nucleus from somatic cell is placed into ovum and given electric shock so it fuses

• embryo is transferred to a third animal

• new animal is clone of the animal which the somatic cell was from but mtDNA comes from egg

two types of artificial cloning in animals

advantages:

• more offspring made

• SCNT allows cloning of specific animals with desired traits

• useful in pharming for human medicines or proteins

disadvantages:

• inefficient

• short live spans and health problems

• many fail to come to term

advantages and disadvantages of animal cloning?

when biological organisms to synthesise breakdown, or transform materials for people

what is biotechnology?

use of biological systems to remove soil and water pollution

natural organisms break donw organic material making CO2 and water

what is bioremediation?

• no welfare issues to consider

• wide range of microorganisms

• short life cycel and rapid growth rate

• nutrient requirements are very simple

• growth conditions are simple like low oxygen and low temps

why are microorganisms used for biotechnology?

microorganisms have an indirect effect as they make one thing that is turned into food

for example bread is made from yeast

what does indirect food production entail?

Microorganisms directly make food such as Quorn

Advantages: fast and wide variety of waste materials can be made

Disadvantages: little flavour, involves GM, need sterile conditions, people don’t want to eat

direct food production from microorganisms

penicillin and insulin are made using GM

what medicines are made using biotechnology?

• asceptic technique needs to be used

• inoculating broth where the bacteria and nutrients both are mixed then incubated

• wire inoculating loop must be sterilised by fire and ethanol

• can be done in agar or in a lab

how to culture microorganisms

lag phase - bacteria adapt to new environment

log or exponential phase = birth rate>death rate

stationary phase - total growth rate is 0, birth rate = death rate

death phase - death rate > birth rate

what does the bacterial growth curve look like?

• nutrient availability

• oxygen and temp levels

• build up of waste products

• change in pH

limiting factors for bacterial growth

N = N₀ * 2ⁿ, where N is the final number of bacteria, N₀ is the initial number, and n is the number of generations or divisions

what is the formula for size of bacterial colonies?

• Primary metabolites are essential for an organism's basic survival formed during active growth

• Secondary metabolites are not directly involved in these processes but, play roles in defense, adaptation, and other specialized functions

what are primary and secondary metabolites?

batch and continuous

what are the two types of bioprocesses?

• inoculated in a fixed volume medium

• waste and products build up

• process stopped before death phase

batch fermentation

• sterile nutrient medium

• nutrient medium is added continuously to culture

• once it reaches exponential growth, cultured broth is continuously removed

continuous fermentation

temperature, nutrients and oxygen, asepsis, mixing

how do you control bioreactors?

• less wasteful

• more efficient and specific

• less unwanted products

advantages of isolated enzymes

easier to isolate since they are secreted
there are fewer types so easier to identify

sometimes used when a specific enzyme is only found inside cells

why are extracellular enzymes mainly used?

when are intracellular enzymes also used?

enzymes that are attached to an inert support system to which the substarte passes over

what are immobilised enzymes?

advantages:

• reused which is cheaper

• easily separated from product

• greater temp tolerance

• allows for efficient controlled reactions

disadvantages:

• reduced efficiency

• higher initial costs of materials and bioreactors

advantages and disadvantages of immobilised enzymes

1. adsorption: stick enzymes to inorganic carriers, simple and cheap but enzymes easily lost

2. ionic or covalent bonding: bond to carriers using these bonds, strongly bound and very accessible to substrate, active site may be modified

3. entrapment in a matrix: widely applicable but active site is not easily available

4. membrane entrapment (encapsulation): simple but expensive

methods of immobilising enzymes?

• penicillin acylase - semi-synthetic penicillins to treat bacteria resistant penicillins

• glucose isomerase to convert glucose to fructose

• lactase

examples of immobilised enzymes uses