Metabolism and Survival Flashcards
1
Q
What does metabolism mean?
A
Metabolism is all the chemical reactions taking place within a cell
2
Q
What is meant by metabolic pathway?
A
A metabolic pathway is the series of chemical reactions occurring in a cell
3
Q
What controls the chemical reactions that take place in a cell?
A
Enzymes
4
Q
What two reactions can a metabolic pathway be?
A
Anabolic or catabolic
5
Q
What is an anabolic reaction?
A
Anabolic reactions build up large molecules from small molecules and require energy.
6
Q
An Example of a anabolic reaction is?
A
Protein synthesis
7
Q
What is a catabolic reaction?
A
Catabolic reactions break down large molecules into small molecules and release energy.
8
Q
An Examples of a catabolic reaction is?
A
Aerobic respiration
9
Q
Why do alternative routes occur?
A
They occur when a specific enzyme or substrate isn’t available in a pathway, then sometimes an end product can still be made by using alternative routes.
10
Q
What can alternative routes do?
A
They can bypass steps in a pathway
11
Q
Alternative routes may take longer but they still result in what?
A
The same or similar end product that is needed.
12
Q
Some organelles have what?
A
Inner membranes which have compartments
13
Q
What do an organelles compartments allow?
A
Metabolic activity to be localised so conditions for reactions are more favourable.
14
Q
What is the function of the outer membrane in the mitochondria?
A
Separate it from the rest of the cell contents.
15
Q
What is the function of the inner membrane in the mitochondria?
A
Provides a large surface area for reactions to take place upon.
16
Q
The chloroplast is also a double membrane structure what does it do?
A
The membrane forms a compartment and allows specific reactions to take place within the chloroplast
17
Q
What happens with the surface to volume ratio with double membranes?
A
The high surface to volume ratio of small compartments creates high concentrations and high reaction rates.
18
Q
What happens to the surface to volume ratio when an object increases?
What does this mean?
A
The surface area to volume ration decreases.
It’s better to have small cells so that the surface area to volume ration is as large as possible to increase the rate of chemical reactions.
19
Q
What does the cell membrane consist of?
A
Protein and phospholipid molecules
20
Q
What type of model is the cell membrane known as?
A
Fluid mosaic model
21
Q
What do the phospholipid molecules do in the cell membrane?
A
Form a double layer and are constantly in motion, giving a fluid nature to membranes and making them flexible.
22
Q
How are the proteins placed in the cell membrane?
What do the proteins in a cell membrane do?
A
Proteins are scattered in a patchy mosaic pattern.
Some proteins form pores, others are pumps that penetrate through the membrane and some are enzymes that catalyse chemical reactions.
23
Q
What are Channel-forming (pores) proteins?
What do they do?
A
Larger molecules depend on certain protein molecules to allow them passage across the membrane.
These protein molecules contain pores. Provide channels for specific substances to diffuse across the membrane. Making the membrane selectively permeable.
24
Q
What are carrier (pump) proteins?
A
Act as carrier molecules which recognise specific ions and transport them across the membrane.
25
What are carrier (pumps) proteins used in?
Active transport and require energy available by ATP.
26
What do enzymes in the molecule do and how are they placed?
They catalyse a specific reaction and organise the sequence of reactions essential to cell.
Embedded in cell.
27
What do metabolic pathways need to be?
Regulated and controlled.
28
How can metabolic pathways be regulated and controlled?
What will they do?
Can be done the presence or absence of a particular enzyme.
Stop the build up of an end product that isn’t needed.
29
What do intracellular and extracellular signalling molecules do?
Control metabolic pathways
30
What is intracellular?
What is extracellular?
Inside the cell
Outside the cell
31
What is an induced fit?
Induced fits occur where the active site of the enzyme changes shape to fit the substrate after the substrate binds.
32
What does affinity mean?
Chemical attraction
33
Substrate molecules have a what affinity for the active site?
While the product have a what affinity and what does it let it do?
High affinity
Low affinity allowing them to leave the active site.
34
What does the high affinity for the active site do?
This orientates the reactants into the correct position for the reaction to take place.
35
What happens when the substrate binds during an induced fit?
Why does this happen?
What does this do?
The enzyme changes shape allowing for a tighter fit with the substrate.
A reaction is more likely to happen as the bonds of the substrate are under tension
36
What is activation energy?
The energy required to initiate a reaction
37
What does the binding of the enzyme to it’s substrate do to the activation energy?
It lowers the activation energy of the reaction
38
What can effect the rate of enzyme reaction?
They can be affected by substrate concentration
39
What happens to the substrate concentration?
The enzyme reaction increases until all active sites are occupied by the substrate.
40
What happens when all active sites are occupied?
The enzyme becomes saturated
41
What does adding more substrate do to the saturated enzyme?
Does not affect the reaction rate
42
What affects an enzyme catalysed reaction?
Concentration of enzyme
Concentration of substrate
Concentration of end product
43
Different what can influence enzyme activity?
Chemicals
44
What do inhibitors do?
What dose it result in?
Stop an enzyme from binding to its substrate.
Inhibitors can directly control the progress of a metabolic pathway
45
What are the two types of inhibitors?
Competitive
Non- competitive
46
What do competitive inhibitors do?
They resemble shape and size of the substrate
Bind to the active site preventing the substrate from binding, slowing the reaction rate.
47
How can competitive inhibition be reversed?
Why?
Increasing substrate concentration.
The substrate eventually dilutes the inhibitor so that all enzyme molecules bind to substrate.
48
What are non-competitive inhibitors?
Binds away from the active site but change the shape of the active site preventing the substrate from binding.
49
Can non-competitive inhibitors be reversed?
No they are irreversible
50
What do competitive and non-competitive inhibitors do to a metabolic pathway?
Affect the reaction rate
51
What is feedback inhibition?
Occurs when the end-product in the metabolic pathway reaches a critical concentration. End product then inhibits an earlier enzyme, blocking pathway, so prevents further synthesis of the end product.
52
What affect does feedback inhibition have?
Process stops the metabolic pathway until end product concentration decreases.
The higher the concentration of end product, the quicker the metabolic pathway stops.
53
What is negative feedback control?
Prevents the cell from wasting energy synthesising a product that they already have in excess.
54
What is cellular respiration?
Cellular respiration is a series of metabolic pathways which brings about the release of energy from a food storage and the regeneration of the high energy compound ATP
55
What controls cellular respiration?
Enzymes
56
Where does glycolysis occur?
Does it require oxygen?
Cytoplasm
No it does not require oxygen
57
Where does the citric acid cycle occur?
Does it require oxygen?
In the matrix of the mitochondria
Yes it requires oxygen
58
Where does the electron transport chain occur?
Does it require oxygen?
Inner membrane of the mitochondria
It does require oxygen
59
In cellular respiration how many ATP molecules are made?
38 ATP per glucose molecule
60
In the break down of glucose what products are produced?
2 molecules of pyruvate are produced
While 2 molecules of ATP is produced for each glucose molecule broken down
61
Pyruvate is further broken down into what?
Carbon dioxide and water
62
To form ATP the cells use what?
The cells use some of the energy from respiration
63
When the cell needs energy what happens?
ATP can be broken down to realise the stored energy
64
How do you make ATP?
Adenosine diphosphate + inorganic phosphate + energy
65
What happens if the cell needs energy?
It can breakdown ATP back to ADP and energy is released
66
What is used to carry out the breakdown of ATP to ADP + Pi?
Enzymes
67
What is phosphorylation?
The adding of a phosphate
68
ATP is used to transfer energy and phosphorylate to cellular process which require energy.
What are some of those processes?
DNA replication, active transport, synthetic pathways and muscle contraction
69
Phosphorylation is a what controlled reaction?
And require what?
Enzyme controlled
Energy
70
The metabolic pathway can be split into three main stages.
what are the stages?
Glycolysis
Critic acid cycle
Electron transport chain
71
What is glycolysis?
The breakdown of glucose into two pyruvate molecules
72
Glycolysis can be split into two stages.
What are they?
Energy investment stage
Energy payoff stage
73
What is the energy investment stage?
2 ATP are used up per glucose molecule and phosphorylation of intermediates occur.
74
What is the energy payoff stage?
4 ATP are produced per glucose molecule
75
What is the net gain of glycolysis?
2 ATP per glucose molecule
76
What do dehydrogenase enzymes do?
Remove hydrogen ions and electron from intermediates and pass them to the coenzyme NAD. Forms NADH which acts as a hydrogen acceptor and carrier.
77
Where do NADH take the hydrogen ions and electrons?
To the inner membrane of the mitochondria for use in the electron transport chain
78
After the dehydrogenation of 2 NAD molecules how many NADH molecules are made?
2 NADH molecules
79
If oxygen is available what happens to the pyruvate molecules?
They progress into the citric acid cycle
80
When does the critics acid cycle occur?
After glycolysis
81
Why is the inner membrane of the mitochondria folded?
To create a large surface area for reactions to occur
82
What is the central matrix?
A fluid filled interior
83
What is the beginning of the citric acid cycle?
When Pyruvate diffuses into the matrix of the mitochondria
84
Pyruvate is broken down into what after carbon dioxide is removed?
An acetyl group
85
Acetyl group and coenzyme A form what when bonded together?
Acetyl coenzyme A
86
In the citric acid cycle what happens to hydrogen ions and electrons?
They are removed and become attached to coenzyme NAD forming NADH
87
What happens when acetyl group coenzyme A combined with oxaloacetate?
The acetyl group from the acetyl coenzyme A combined with the oxaloactate to form citrate
88
How is oxaloacatate converted back to oxaloacatate after combining with the acetyl group?
What does it generate?
A series of enzyme controlled steps, citrate is gradually converted back into oxaloacatate.
Results in the generation of ATP and release of carbon dioxide.
89
In the citric acid cycle how does carbon dioxide leave the cycle?
It diffuses out the cell
90
What is the electron transport chain?
A series of carrier proteins attached to the inner mitochondrial membrane.
91
What does NADH do once in the electron transport chain?
Release the electrons to the electron transport chain where they pass along the chain releasing energy.
92
What does the energy realised by NADH do?
Energy allows hydrogen ions to be pumped across the inner mitochondrial membrane from the matrix
93
How does the protein ATP synthase work?
The return flow of the hydrogen ions back through the membrane to the matrix and rotates the membrane protein ATP synthase
94
What does the rotation of the protein ATP synthase result in?
The production of ATP from ADP + Pi
95
What do electrons do at the end of the electron transport chain?
Combine with oxygen, while the oxygen combines with hydrogen to form water
96
What is oxygen in the electron transport chain?
The final electron acceptor
97
What happens if oxygen is not present in the electron transport chain?
Electron transport chain does not operate and this major source of ATP become unavailable to the cell
98
How many ATP molecules are mad from 1 molecule of glucose over all?
38 ATP
99
When does fermentation occur?
When oxygen is not available
100
Where does fermentation take place?
Cytoplasm
101
What happens during the process of fermentation?
Sugar is only partially broken down and very little energy is released.
102
Since oxygen is not present which stages will occur in cellular respiration?
Only glycolysis will occur
103
In animals what is the product of fermentation?
Lactate
104
In plants and fungi what is the product of fermentation?
Ethanol and carbon dioxide
105
Is fermentation reversible?
Yes but only in animals and not in plants and fungi
106
In fermentation how many molecules of ATP are released from 1 molecule of glucose?
2 ATP molecules
107
What is fermentation less of compared to aerobic respiration?
Fermentation is less efficient
108
What is metabolic rate?
The quantity of energy consumed per unit time
109
ATP is mainly generated by what?
Aerobic respiration
Glucose + Oxygen —> Carbon dioxide + water + energy
110
How could metabolic rate be measured?
Oxygen consumption per unit time
Carbon dioxide production per unit time
Energy production per unit time
111
What does the measure of oxygen consumed by the body do?
It give an indirect measure of energy expenditure which is known as indirect calorimetry
112
How can heat production be measured?
Can be measured directly which is a process called direct calorimetry
113
How is heat production measured?
Subject is placed in an insulated chamber and the temperature rise of a known mass of water is calculated
114
The formula of measuring energy expenditure is?
Energy (calories)= mass of water (g) x temperature change (C)
115
How accurate is the formula for measuring energy expenditure?
This method is extremely accurate
116
How are respirometers used?
Used to measure metabolic rate
Can track temperature, oxygen concentration and carbon dioxide concentrations in real time using probes linked to computers
117
What do respirometers measure?
The volume of oxygen uptake or carbon dioxide produced by an organism to measure metabolic rate
118
What do calorimeters measure?
Heat generated by an organism to determine metabolic rate
119
What data can exercise tests provide?
Monitor the effectiveness of a training program for an athlete
Monitor recovery e.g heart attack
120
Organisms with high metabolic rate require what?
Efficient delivery of oxygen
121
What are the three different circulatory systems in vertebrates?
Single circulatory system
Incomplete double circulatory system
Complete double circulatory system
122
What organism has a single circulatory system?
Fish
123
What organism Incomplete double circulatory system
Amphibians and most reptiles
124
What organism has a complete double circulatory system?
Birds, mammals and some reptiles
125
How many times does blood pass through the heart in a single circulatory system?
Passes through the heart once
126
How many chambers does a single circulatory system have?
What are they?
Two
One atrium and one ventricle
127
In the single circulatory system where is the blood pumped from and what happens to the blood?
Pumped from the ventricle to the gills where it is oxygenated.
128
What happens to the oxygenated blood in the single circulatory system?
The oxygenated blood travels around the body cells before returning to the atrium.
129
What is the main disadvantage of the single circulatory system?
The gill capillaries offer so much resistance to blood flow that blood pressures to the body tissue are greatly reduced
130
How many times does blood pas through the heart in an incomplete double circulatory system?
Blood passes twice through the heart
131
How many chambers does the heart have in a incomplete double circulatory system?
What are they?
It has three chambers
Two atria and one ventricle
132
What type of blood returns from the body tissue to the right atrium?
Deoxygenated blood
133
What type of blood returns from the lungs to the left atrium of the heart?
Oxygenated blood
134
Blood is passed from how many atria into the ventricle to exit the heart?
Both atria
135
What type of blood is pumped at high pressure to both the lungs and the body tissue at the same time in an incomplete double circulatory system?
Mixed blood
136
Amphibians heart maintain what?
Why?
High blood pressure
Because oxygenated blood from the lungs returns to the heart before it is pumped to the body tissue
137
What is the main disadvantage of the incomplete double circulatory system?
Oxygenated and deoxygenated blood are mixed in the single ventricle in the heart. This reduces efficiency as the tissue blood is not completely oxygenated
138
How many times does blood pass through the heart in a complete double circulatory system?
Blood passes through the heart twice
139
How many chambers does the complete double circulatory system have?
What are they?
Four chambers
Two atria and two ventricles
140
Unlike the ventricles in an incomplete double circulatory system what feature do the ventricles in a complete double circulatory system have that they don’t?
The ventricles are completely separated by a septum.
141
What type of blood returns from the body tissue to the right atrium of the heart in a complete double circulatory system?
Deoxygenated blood
142
In a complete double circulatory system blood is passed from where?
Which is then pumped to where?
Blood is passed into the right ventricle which pumps it to the lungs.
143
What type of blood returns from the lungs to the left atrium of the heart and is passed into the the left ventricle?
Oxygenated blood
144
In a complete double circulatory system oxygenated blood is passed from the left ventricle. After this it is then pumped at what type of pressure and to where in the body?
Oxygenated blood is pumped at a high blood pressure to the body tissue.
145
How efficient is a complete double circulatory system?
Why is that?
It is very efficient
This is because it is pumped at a higher pressure and the tissue blood is completely oxygenated
146
An organism ability to maintain its metabolic rate is affected by what?
It is affected by external abiotic factors
147
What type of fluctuations can occur in an organisms environment?
Temperature, salinity or ph
148
What are conformers?
They are organisms that are unable to alter their normal metabolic rate
149
What are regulators?
They are organisms that are able to alter their normal metabolic rate and maintain a steady state
150
How do conformers work?
Their internal environment is dependent on their external environment.
151
Conformers live in what type of environment?
What type of metabolic cost do they have?
Environments that remain relatively stable
They have low metabolic costs
152
What type of behavioural response do they have?
What do they help maintain?
Behavioural responses which allow them to tolerate variation in their external environment to maintain an optimum metabolic rate
153
What are conformers restricted to?
They are restricted to a narrow range of ecological niches
154
How do regulators work?
Regulators maintain their internal environment regardless of their external environment
155
How do regulators use their metabolism?
What does it help increase?
They use their metabolism to control their internal environment.
which increases the range of possible ecological niches
156
What does regulation require?
Why does this requirement achieve?
Energy
To achieve homeostasis
157
What does homeostasis help increase in regulators?
Helps increase their metabolic costs.
158
What is an adverse condition?
Adverse conditions are environmental conditions which vary beyond the tolerable limits for normal metabolic activity.
159
Organisms have adapted how to adverse conditions?
Organisms have adapted to either avoid or survive adverse conditions.
160
What ways can an animal adapt to these adverse conditions?
Animals can reduce their metabolic activity through dormancy
161
What is dormancy?
Dormancy is part of some organisms life cycle to allow survival during a period when the costs of continued normal metabolic activity would be too high.
162
An organisms metabolic rate can be reduced during dormancy to save energy. Which leads to a decrease in what?
Heart rate
Breathing rate
Body temperature
163
What are the two types of dormancy?
Predictive dormancy
Consequently dormancy
164
What is predictive dormancy?
Occurs before the onset of adverse conditions
165
What is consequential dormancy?
Occurs after the onset of adverse conditions
166
What are examples of dormancy?
Hibernation
Aestivation
Daily torpor
167
What is hibernation?
Hibernation allows some animals to survive during winter/low temperature.
168
Is hibernation predictive or consequential?
It can be either predictive or consequential
169
What is aestivation?
Aestivation allows survival in periods of high temperature or drought
170
Is aestivation consequential or predictive?
Consequential dormancy
171
What is daily torpor?
Daily torpor is a period of reduced activity in some animals with high metabolic rates.
It only lasts a few hours and can be seen as a short-term hibernation
172
What is migration?
Migration is the regular movement by the members of a species from one place to another over a relatively long distance.
173
What can migration help avoid?
Can be used to avoid metabolic adversity
174
How does migration help avoid metabolic adversity?
It helps as it involves using energy to relocate to a more suitable environment.
175
What is innate behaviour?
Innate behaviour is inherited from parents to offspring and is likely to be the biggest influence on successful migration.
176
What is learned behaviour?
Learned behaviour is gained by experience. It may come from parents or other members of a social group
177
4 important facts about innate behaviour?
Inherited and inflexible
Primary role in migratory behaviour
Performed in same way by every member of species
Occurs in response to an external stimulus
178
3 important facts about learned behaviour?
Begins after birth and is gained by experience
Is flexible and a result of trail and error and relearning from members of a social group
Plays a secondary role in migratory behaviour
179
What is it that scientists want to find out when studying migration?
When the animal migrates
Where they migrate to
If they return to their original territory
How long they live for
180
How can scientists find out all the information they want to know about migration?
By marking or tracking
181
How does marking work?
Marking an animal requires you to capture and then tag it with a marker.
The animal will migrate and will be recaptured to gather data.
182
How does tagging work?
Tracking involves a transmitter being attached to the animal.
A recover picks up the single being transmitted and the animal can be tracked to a precise location
Allows for the animals migratory path to be plotted and days can be transmitted without having to recover the transmitter
183
What are the three domains of life that microorganisms come from?
Archaea
Bacteria
And some species of eukaryotes
184
How are microorganisms useful to humans?
Due to their:
Adaptability
Ease of cultivation
Speed of growth
185
Properties of microorganisms are?
They are highly adaptable
Wide variety of substrates for their metabolism
Produce a range of products from their metabolic pathways.
186
What are microorganisms grown in?
Grown in Petri dishes
Flasks
bottles
Huge stainless steel fermenters in large industrial processes
187
What do microorganisms need to grow?
Chemical substrates
Light in photosynthetic microorganisms
188
What are the complex molecules required for biosynthesis?
Vitamins, amino acids and fatty acids.
189
What can growth media be composed of?
Either specific substances or can contain complex ingredients such as beef extract
190
What are the certain conditions needed to be controlled when microorganisms are cultured?
Sterility
Temperature
Oxygen levels
pH
191
Why have sterile conditions?
Having sterile conditions reduce competition with desired microorganisms for nutrients and reduce the risk of spoiling of the product
192
Why must aseptic techniques be followed?
Must be followed when preparing and inoculating the growth media
193
In industry microorganisms are grown in a fermenter how are the conditions controlled?
Sensors detect any changes and send information to computers which control the conditions.
194
How do you define growth?
Growth occurs when the rate of synthesis of organic materials by an organism exceeds the rate of their breakdown.
195
What is growth?
An irreversible increase in dry biomass.
196
Why is growth measured using dry biomass?
Due to it being a more reliable indicator of growth than gain in fresh mass because an organisms fresh biomass varies depending on water availability which is independent of growth.
197
How can growth be measured in unicellular organisms?
By measuring increase in cell number over a period of time.
198
What is a viable cell count?
Gives the number of cells that are alive and capable of reproduction
199
What is a total cell count?
Refers to all cells dead or alive
200
What are the 4 phases of bacterial growth?
Lag
Log/exponential
Stationary
Death
201
What is the lag phase and what happens?
Where enzymes are induced to metabolise substrates.
Little or no increase in cell number as cells adjust to the growth medium and metabolic increases
202
What is the log/ exponential phase and what happens?
Contains the most rapid growth of microorganisms due to plentiful nutrients.
203
What is mean generation time?
The time needed when the population doubles its number with each cell division
204
What is stationary phase and what happens?
Stationary phase occurs due to nutrients in the culture becoming depleted and the production of toxic metabolites.
Also death rate and new cells produced are equal
205
When are secondary metabolites produced?
During the stationary phase
206
What are secondary metabolites?
Antibiotics
207
In the wild what do secondary metabolites help do and how do they help do that?
Help confer an ecological advantage by allowing microorganisms which produce them to our compete other microorganisms.
208
What is the death phase and what happens?
Death phase occurs due to toxic accumulation of metabolites or the lack of nutrients in the culture.
Number of cells dying greatly exceeds number of new cells being produced
209
When improving a microorganism what are features that the selected strains may still lack?
Genetic stability
Ability to grow on low cost-nutrients
Ability to overproduce target compound for which selected
Ability to allow easy harvest of the target product following the fermentation process
210
Why may scientists want to change the dna of wild strains of microorganisms?
So that they can produce useful substances or produce useful substances more efficiently
211
How can scientists improve strains of microorganisms?
By mutagenesis
Recombinant DNA technology
212
What is mutagenesis?
The process of changing a microorganisms genetic material using mutagenic agents
213
What is a mutation?
A random change to genetic information
214
What does a mutagenic agent do?
A mutagenic agent increases the rate of mutations
215
What are the two main types of mutagenic agents?
Uv light and chemical mutagenic agent
216
What does exposure to uv light or mutagenic chemicals result in?
Mutations which may produce an improved strain of microorganisms
217
Mutant strains of microorganism are usually what?
Genetically unstable
218
What happens to mutant strain that are cultured over generations?
They can revert back to the original wild type
219
Because mutant strains can revert back to their original wild type what must scientists do to make sure this doesn’t happen?
Monitor them regularly
220
What is recombinant dna technology?
It is a technology which involves the use of recombinant plasmids and artificial chromosomes as vectors
221
What does recombinant dna technology enable scientists to do?
To transfer gene sequences from one organism to another/one species to another
222
What are restriction endonuclease?
Enzymes that cut open plasmids and cut specific genes out of chromosomes.
223
Restriction endonuclease cut what into fragments?
Restriction sites into fragments with sticky ends
224
What are sticky ends?
Sticky ends are pieces of dna that have unpaired nucleotides and the end of them.
225
What are ligase?
They are an enzyme used to seal the gene into the plasmid
226
Ligase are able to do what?
Able to join two different fragments dna together
227
Why are ligase able to bind to bind the sticky ends of the dna fragments together?
Because the same restriction endonuclease was used the sticky ends are complementary to each other.
228
The plasmid is inserted back into bacterial body cell and the inserted gene is what?
Expressed
229
The products produced by the expressed gene will be what?
Produced in large quantities and can be harvested and purified
230
What is a vector?
A dna molecule used to carry foreign genetic information into another cell
231
What materials can be used as vectors?
Recombinant plasmids and artificial chromosomes
232
What do vectors contain?
Marker genes, restriction sites and an Irving in of replication
233
What do marker genes do?
Ensure that only microorganisms that have taken up the vector grow in the presence of the selective agent
234
What is the selective agent that marker genes detect?
Antibiotic resistance or fluoresce
235
Origins of replication consists of genes that control what?
Self replication of plasmid dna
Regulatory sequences that control the expression of existing genes and inserted gene
236
In expressing genes form eukaryote in prokaryote what are the limitations of prokaryotes ?
Prokaryote dna does not have introns so is not spliced
Proteins do not undergo post-translational modification
237
A gene from a eukaryote expressed by a prokaryote may produce an inactive polypeptide due to what?
Incorrect folding
Lack of post translational modification
238
Recombinant Yeats cells can’t be used as vectors to produce what?
Proteins that would normally be found in animals or plants
239
The use of eukaryote, such as yeast do what?
Overcome issues with incorrect folding and lack of post-translation modifications
240
What are some arguments in favour for recombinant dna technology?
Might improve nutrition and food security by increasing quantity and quality of food.
Might improve the environment by allowing reduction of the use of pesticides of fertilisers.
Might improve health by the production of drugs that are otherwise difficult to produce
241
What are arguments against recombinant dna technology?
Potential impact of the technology is unknown and many aspects of it such as the safety of foods or drugs remain to be understood.
Risks of the organism k’s or the gene they contain escaping are too great and could not be reversed.
Genes are self-perpetuating, and the risks that they might bring in the future are unknown
