Unit 6 - Cloning and biotechnology Flashcards Preview

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Flashcards in Unit 6 - Cloning and biotechnology Deck (91)
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1
Q

Clones

A

Carry identical genetic material because they are derived from the same orig. DNA

2
Q

Cloning

A

Process of producing genetically identical cells or organisms from the cells of existing organisms through nonsexual means

3
Q

Examples of processes that form genetically identical organisms

A

Mitosis
Binary fission (bacteria)
Budding (yeast)

4
Q

Natural plant cloning

A

Vegetative propagation through runners or suckering

5
Q

Artificial plant cloning

A

Artificial vegetative propagation through cuttings or micropropagation (tissue culture)

6
Q

Vegetative propagation

A

Ability of plants to reproduce w/out sexual reproduction by producing new plants from existing vegetative structures

7
Q

Vegetative structures

A

Non-reproductive tissues e.g. roots, leaves and stems

8
Q

Cuttings

A

Cut stem 1/4 “ below internode at 45-60 degrees
Treat cut end w/ rooting hormones
Cover in clear plastic bag
Transfer to another growing medium

9
Q

Why do you cover cuttings w/ a clear plastic bag

A

To keep it moist and warm

10
Q

Explant

A

A small piece of tissue

11
Q

Callus

A

Undifferentiated mass of tissue containing totipotent cells

12
Q

Micropropagation

A

Cut out explant from vegetative structures (leaf)
Sterilise explant w. alcohol
Place explant in sterile agar w/ glucose, cytokinins and auxins
Subdivide callus and place on growth medium to induce root growth (prepares plant for transplanting)
Transferred to greenhouse to acclimatise before being planted outside

13
Q

Advantages of artificial plant cloning

A

Can produce large no. v. quickly
Can grow plants that dont reproduce easily
No need to wait for seed production
Reproduce sterile plant

14
Q

Disadvantages of artificial plant cloning

A

Labour intensive and requires skilled workers
Trial and error to find ideal conditions for growth
Undesirable traits also passed on
Can fail to microbial contamination

15
Q

Runners

A

Side stem grows out from bud at the base of the main stem

Creates new bud and grows a vertical stem

16
Q

Suckering

A

Grow from shallow roots from buds that are normally dormant
Duing times of stress, buds are activated and suckers form many metres away from parents tree (to avoid stress that triggered growth)
Eventually form clonal patch of new trees
Trees in clonal patch put out new sucker buds

17
Q

Advantages of natural plant cloning

A

Large colonies can form quickly

Allows species to survive catastrophic events

18
Q

Disadvantages of natural plant coning

A

No natural selection

Susceptible to gentic disease; no variation

19
Q

Runners vs. suckers

A

Runners are overground and suckers are underground

20
Q

Why must the agar used in micropropagation be sterile

A

Prevents infection

Competition of resources e.g. oxygen/nutrients if other organisms e.g bacteria and fungi are present

21
Q

Somatic cell

A

Biological cell forming the body of an organism

22
Q

Germline cell

A

Biological cell that gives rise to the gametes of an organism that reproduces sexually

23
Q

Natural animal reproductive cloning

A

Some animals can regenerate entire animals from fragments of the orig. (starfish)
Others fragment and form new identical animals as part of their normal reproductive process (flatworms and sponges)
MZ twins form when an early embryo splits and and two foetuses develop from two halves

24
Q

Artificial animal reproductive cloning

A

Somatic cell nuclear transfer

Artificial twinning

25
Q

Somatic cell nuclear transfer

A

Extract nucleus from somatic cell from Sheep A
Remove nucleus from egg cell from Sheep B
Insert nucleus from A into innoculated egg(electrofusion)
Stimulates to divide in vitro and implant embryo into sheep C

26
Q

Artificial embryo twinning

A

Get fertilised egg and allow to divide until 16 cell stage
Harvest embryo and split into smaller ones manually
Implant into surrogate mothers which give birth to identical high quality animals

27
Q

Advantages of artifical animal cloning

A

Produce identical clones w/ desirable traits
Stem cell research
Clones so offspring can be produced all year round

28
Q

Disadvantages of artificial animal cloning

A

Difficult and time consuming
Destruction of embryos unethical
Clones have shorter life expectancies
No genetic identity so selection pressures affects all

29
Q

Similarities between AT and SCNT

A
Produce clones 
Both have surrogates 
Divides by mitosis 
Unnateral 
Expensive
30
Q

Differences between AT and SCNT

A

AT forms several clones at once
Gametes meet outside the body is AT
SCNT involves only maternal DNA
No fertilisation in SCNT

31
Q

Biotechnology

A

Industrial exploitation of living micro-organisms (or parts of them) and biological process to produce useful substances for human use

32
Q

Why are microorganisms used in biotech

A

Easy/ not labour intensive
Obtain pure products if aseptic technique is followed
Can be easily genetically enginerred to produce spp products
Short life cycle
Simple requirements for growth - can be left w/ little intervention
Can be grown v. quickly
Can be grown on waste material from other processes

33
Q

Use of microorganism in biological processes

A
Brewing - anaerobic respiration of yeast
Baking - yeast
Cheese making - bacteria and rennin 
Penicillin production - fermentation by fungus 
Insulin production - GM bacteria
Bioremediation
34
Q

Bioremediation

A

Using microorganisms to clean up pollution

Convert toxic pollutants to less harmful substances

35
Q

Advantages of bioremediation

A
Uses natural systems 
Less labour and equipment required
Treatment can be carried out on site
Few waste products produced 
Less risk of harmful exposure to clean-up personnel
36
Q

Culturing microorganisms

A

Sterilisation - Sterilising equipment in an autoclave (15 mins at 121 degrees)
Inoculation - Introducing a sample of microorganisms to the growth medium
Incubation - Place in a warm environment and place agar plate upside down (condensation)

37
Q

Types of growth medium

A

Agar jelly in a petri dish

Nutrient broth in a bijoux bottle

38
Q

Standard procedure of aseptic techniques

A

Wash hands thoroughly
Disinfect working area
Light and keep Bunsen burner on
Flame neck of bottle before and after taking sample
Lift lid of petri dish slightly to introduce microbe by streaking
Close petri dish and tape (not completely)
Flame all equipment after use
Wash hands again

39
Q

Why do you keep the Bunsen burner on during aseptic procedures

A

Heats the air, causing it to rise so air-borne microbes don’t settle

40
Q

Why cant you seal the petri dish completely

A

Introduces O2 for aerobic respiration

Doesn’t introduce harmful anaerobically respiration organism

41
Q

Continuous culture

A

Culture is set up and nutrients are added and products removed from the culture at intervals - done at same rate to keep vol constant
Culture is maintained at exponential growth phase - grows and produces metabolites faster

42
Q

Metabolites

A

Substances produced by living organisms in order to survive e.g ATP synthase

43
Q

Batch culture

A

A starter population of the microorganism is given a fixed amount of nutrients and at the end of the time period products are extracted

44
Q

Examples of continuous culture

A

Insulin

Single-cell protein (from Fusarium)

45
Q

Examples of batch culture

A

Wine
Beer
Yogurt

46
Q

Advantages of continuous culture

A

Fermenter is always in use - increases efficiency
High growth rate as nutrient levels maintained
Useful for primary metabolites

47
Q

Disadvantages of continuous culture

A

Contamination is more likely
Difficult to maintain and control product consistency
In cases of contamination losses are great and all production halts

48
Q

Advantages of batch culture

A

Less likelihood of contamination
Can be left for a set time period
Useful for secondary metabolites
In the event of contamination, only one batch is lost

49
Q

Disadvantage of batch culture

A

Fermenter isn’t in use constantly - less efficient

Time spent cleaning

50
Q

Primary metabolites

A

Produced in the course of normal metabolism e.g. proteins, enzymes, alcohol
Produced in lag and log phase

51
Q

Secondary metabolites

A

Produced after main population growth has occurred, nutrients are in short supply and population isn’t growing rapidly
Produced in stationary and death phase

52
Q

How do fermenters maximise the yield

A

Tube for sterile air to provide oxygen for aerobic reactions
Sparger - diffuses air through culture medium
Powerful motors - mixes contents ensuring equal distribution of nutrients and so microbes don’t settle at base of fermenter
Acid-base injection site - controls pH
Culture broth - contains sources of carbon and nitrogen (NH3) and vitamins/minerals
Jacket - filled with hot/cold water to provide optimum temp as respiration releases heat (denaturing)

53
Q

Asepsis in fermenters

A

Washing. disinfecting and steam cleaning all equipment
Using fermenter made of polished stainless steel so microbes cant stick
Sterilising all nutrients w/ steam or heat
Only bubbling in sterile air- v. fine filters

54
Q

Phases in microorganim growth curves (bacteria/fungi)

A

Lag
Exponential
Stationary
Death

55
Q

Lag phase

A

Reproduction v. slow as cells acclimitase, absorb nutrients
Gene expresion for spp enzymes
Synthesis of enzymes and organelles

56
Q

Exponential phase

A

Reproduction is rapid
No limiting conditions
Few cells die

57
Q

Stationary phase

A

Population remains constant as death and reproduction rates are the same

58
Q

Death phase

A

Lack of resources

Build up of CO2 - fatal

59
Q

Culture

A

A method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled lab conditions

60
Q

Isolated enzymes

A

Taking enzymes out of microorganism

61
Q

Issue w/ isolated enzymes

A

Product must be seperated from enzymes and extraction is v. expensive

62
Q

Immobilised enzyme

A

Enzymes fixed to a surface and do not freely mix w/ the substrate

63
Q

Ways to immobilise enzymes

A

Covalent bonding
Encapsulation
Adsorption
Entrapment

64
Q

Covalent bonding to immobilise enzymes

A

Covalently bonded to a supporting surface

Enzymes are also covalently bonded together using a cross-linking agent

65
Q

Adsorption

A

Bound to supporting surface by a combination of hydrophobic interactions and ionic links
Bound w/ active site exposed and accessible to substrate

66
Q

Entrapment

A

Trapped in a matrix (often calcium alginate beads) that doesn’t allow free movement

67
Q

Encapsulation/membane separation

A

Separated from reaction mixture by a small permeable membrane - microcapsule

68
Q

A vs D of adsorption

A

Simple and cheap
Can be used in a variety of processes
Enzymes v. accessible

May distort active site
Enzymes can detach and leak into reaction mixture

69
Q

A vs D of covalent bonding

A

Enzyme less likely to become detached
pH and substrate conc have little effet on enzyme activty
Accessible to substrate

Expensive
Can distort active site, reducing activity

70
Q

A vs D of encapsulation

A

Relatively simple
Relatively small effect on enzyme activity
Widely apllicable to diff processes

Expensive
Substrate and product has to be small in order to diffuse through partially permeabe membrane
Diffusion is slow

71
Q

A vs D of entrapment

A

Widely applicable to diff processes

May be expensive
Difficult to entrap
Effect of entrapment on enzyme activity dpends on the matrix
Substrate and product needs to be small

72
Q

Examples of immobilised enzymes

A
Glucose isomerase 
Penicillin acylase
Lactase
Aminoacylase
Glucoamylase
Nitrile hydratase
73
Q

Penicillin acylase

A

Converts naturally produced penicillins to semi-synthetic penicillins
Some resistant microorganims arent resistant to semi-synthetic penicillins

74
Q

Glucose isomerase

A

V. commonly use to produce HFCS, sweeter than sucrose and can be used in diet fods
Glucose —> fructose

75
Q

Lactase

A

Hyrolyses lactose into glucose and galactose so lactose-intlerant people can drink milk and reduce the risks of developing osteoporosis as a lack of calcium

76
Q

Aminoacylase

A

N-acyl-amino acids —> pure sample of L-amino acids

Used in synthesising pharmaceutical compounds

77
Q

Glucoamylase

A

Dextrins —> glucose

Immobilised and used to digest sources of starch e.g. corn and cassava

78
Q

Nitrile hydratase

A

Nitriles —> amides
Acrylamide can be polymerised to form a plastic and a gel for electrophoresis
Used to treat water, helps to stick many small contaminanrts together so they can be filtered out

79
Q

Supporting surfaces

A

Glass
Porous carbon
Clay

80
Q

Advantages of immobilising enzymes

A

Lowers temp required
No contamination of end product
Reusable
Protected by immobilisng matrix so high temp or extreme pH has no effect

81
Q

Disadvanages of immobilising enzymes

A

Expensive to set up
Bonding may affect active site
Contamination is v. costly as whole system needs to stop
Slower process as enzymes and substrates don’t mix freely

82
Q

Making yoghurt

A

Milk is fermented by bacteria
Lactose—> lactic acid
Low pH denatures caesin, causing milk to coagulate and thicknes
Also adds flavour

83
Q

Makng cheese

A

Milk is fermented by bacteria
Lactose –> lactic acid, acidifies milk
Rennin coagulates caesin in the presence of Ca2+
Resulted curd separates from liquid whey by curdling, stirring and heating

84
Q

Microorganisms in baking

A

Flour is mxed w. water, salt and yeast

Respires anaerobically and produces CO2 bubbles, causing the dough to rise

85
Q

Making wine

A

Grapes have yeast on the surface

When crushed uses glucose and fructose to respire and produce CO2 and alcohol

86
Q

Making beer

A

Uses malted barley grains that are beginning to germinate
Stored starch to maltose, respiratory substrate for yeast
Produces CO2 and alcohol

87
Q

Making penicillin

A

Fermentation of fungus as a batch culture for 6-8 days
Secondary metabolite
Once fermentation is complete, culture is filtered to remove cells
Antibiotics precipitated and purified

88
Q

Making insulin

A

Genetic modification of bacteria

Grown in fermenters, continuous culture

89
Q

Why is the Sheep C treated w/ hormones

A

Increase thickness and vascularisation of uterine lining

90
Q

How can SCNT help save endangered species

A

Doesn’t require fertile females
Female not put at risk during mating
Can subdivide successfully formed embryo

91
Q

Economic advantages of immobilising enzymes

A

Reusable so less money required

Higher temp means profit from faster yield