OCR biology - biotechnology
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| Define biotechnology | The industrial use of living organisms and biological processes to improve agriculture, food science, medicine, animal husbandry, industry, waste treatment
🗑
|
||||
| How is biotechnology used in agriculture? | GM crops, micropropagation
🗑
|
||||
| How is biotechnology used in food science? | Cheese production: lactobacillus bacteria respire lactose anaerobically -> lactic acid. Quorn (MYCOPROTEIN) production: fungus Fusarium Venenatum. Wine production: yeast respire glucose + fructose in grapes anaerobically -> ethanol. GM food crops e.g. Gol
🗑
|
||||
| How is biotechnology used in medicine? | gene therapy, drug-producing microorganisms e.g. Penicillium produces antibiotics, GM
🗑
|
||||
| How is biotechnology used in industry? | Enzyme-producing microorganisms (e.g. A. niger fungus produces pectinase naturally, used for fruit juice extraction) and bio-gas production by methanogenic bacteria grown on sewage
🗑
|
||||
| How is biotechnology used in waste water treatment? | Microorganisms are grown on waste water, feed on waste matter, no longer harmful
🗑
|
||||
| Why are microorgniams used in biotechnology? | Reproduce rapidly (generation time: 30 mins), large yield, can be GMed easily, grown on waste matter (cheaper FEEDSTOCK), grown in fermenters anywhere in the world/ don't take up much space, products purer than those produced by chemical processes
🗑
|
||||
| Define culture and closed culture | Culture - growth of microorganisms on nutrient medium (broth/agar), pure=1 species, mixed =several species. Closed culture - self-contained, conditions are fixed, no materials/ organisms are added or removed
🗑
|
||||
| What is the standard growth curve? | Models the population growth of a small group of organisms in a fresh, closed culture. Lag, log, stationary and decline phases
🗑
|
||||
| Describe the lag phase | Population size increases slowly, organisms are adjusting to surroundings (taking in water, activating certain genes, synthesising enzymes)
🗑
|
||||
| Describe the log phase - what affects the length of this phase | Population size doubles per generation because each individual has sufficient space and nutrients to reproduce, generation time can be as short as 30 mins. depends on how quickly organisms reproduce + take up nutrients/ space
🗑
|
||||
| Describe the stationary phase | Reproduction rate = death rate, because nutrient levels decrease and waste materials accumulate (metabolites e.g. CO2)
🗑
|
||||
| Describe the decline phase | Death rate exceeds reproduction rate due to nutrient exhaustion and high concentration of waste materials, eventually all organisms die
🗑
|
||||
| What are primary metabolites? | Substances produced by organism as part of normal growth/ METABOLISM (amino acids, nucleic acids, lactate, ethanol, proteins), produced by all organisms all the time so production matches population growth of organism
🗑
|
||||
| What are secondary metabolites? | Produced by organism not as part of normal growth/ metabolism, only produced by some organisms, production starts after main growth phase (metabolic activity growth/reproduction) so doesn't match population growth. Antibiotics in stationary phase
🗑
|
||||
| What is batch culture? | Microorganism starter culture + certain quantity of nutrient, closed culture, fermenter is drained. Standard growth curve, pop growth decreases. 2dry metabolites - stress in stationary/ decline phase. Less efficient, contamination =only 1 batch discarded
🗑
|
||||
| What is continuous culture? | Nutrients are added/ wastes are removed at regular intervals, open culture, reservoir. Always log phase. Primary metabolites/ microorganisms. More efficient - fermenter is always in use. Contamination - large volume of product lost, expensive
🗑
|
||||
| How can you adjust growing conditions to maximise the yield? | Temperature: thermostatically-controlled water jacket removes heat from respiration, could denature enzymes. Nutrients: glucose, amino acids, vit/mins. Time of adding. High [O2] for aerobic respiration . pH buffers, probe, denaturation. Paddle- mix evenly
🗑
|
||||
| Draw and label a fermenter | Inlet for steam (disinfectant), inlet for nutrients, inlet for sterile air, inlet for water jacket, water jacket, outlet for water jacket, motor (rotates paddle), paddle, stainless steel, outlet for product with tap, pressure vent, electronic probe
🗑
|
||||
| Define downstream processing | Separation and purification of the product of large scale fermenters e.g. filtration, centrifugation
🗑
|
||||
| Define asepsis and aseptic technique | Asepsis - absence of unwanted microorganisms (contaminants). Aseptic technique - measures taken to prevent culture/ product being contaminated by unwanted microorganisms
🗑
|
||||
| Why is the lack of asepsis a problem? | Contaminants could: compete with culture microorganisms for space and nutrients, reduce growth rate, reduce product yield, release toxic chemicals, spoil product (dangerous for medicinal/ food products), kill culture microorganisms
🗑
|
||||
| How is asepsis achieved at a small/ starter-culture scale? | Regularly disinfect work benches, wear gloves, keep air flowing through fume cupboard, sterilise all apparatus before use with UV/flame, flame the necks of containers, keep lids on culture
🗑
|
||||
| How is asepsis achieved at a large scale? | Use polished stainless steel fermenters to prevent microorganisms form sticking, sterilise air and nutrients, disinfect/ steam clean pipes and fermenter when not in use, fit all inlets and outlets with fine filters
🗑
|
||||
| What are immobilised enzymes + 4 methods? | Enzymes are held separately from the reaction mixture, attached to an insoluble material: adsorption, covalent bonding, entrapment, microspheres
🗑
|
||||
| Describe adsorption | Enzymes bind to a porous support (clay, resin, carbon, glass bead) by hydrophobic interactions/ ionic bonds. High reaction rate provided active sites are on display, not guaranteed. WEak bonding = leakage
🗑
|
||||
| Describe microspheres | Enzymes are trapped inside spheres of partially permeable membrane e.g. chitosan-alginate, active site is unchanged, substrate and reactant are small enough to diffuse across membrane
🗑
|
||||
| Describe entrapment | Enzymes are trapped inside cellulose fibres/ sodium alginate beads/ silica gel. Active site is unchanged. Low reaction rate as active site is poorly accessible by substrate, which has to diffuse through trapping barrier
🗑
|
||||
| Describe covalent bonding | Enzymes bind to a support (cellulose) by covalent bonds, aided by a cross-linking agent e.g. glutaraldehyde, doesn't immobilise much enzyme but strong bonds = no leakage
🗑
|
||||
| What are the advantages of immobilising enzymes? | Low costs of downstream processing/ enzymes absent from product, enzymes are more stable so are less likely to be denatured by temperature/pH changes, enzymes are immediately available for reuse, long-lasting
🗑
|
||||
| What are the disadvantages of immobilising enzymes? | Preparation is time consuming and costly, enzyme catalysis is less efficient e.g. entrapment, contamination is costly, leakage may occur
🗑
|
||||
| How would you make lactose-free milk? | Mix lactase and sodium alginate solution, add droplets to CaCl2 solution forming gel beads containing immobilised lactase, pour milk through a column packed with beads, milk travels slowly allowing time for enzyme catalysis
🗑
|
||||
| Compare the use of immobilised enzymes and immobilised cells | Immobilised cells: cheaper/ quicker to prepare, enzymes don't leak. Immobilised enzymes: more efficient enzyme catalysis, product isn't contaminated/ used up by cells
🗑
|
||||
| Define metabolite | A product of an enzyme-catalysed reaction in cells that can enter subsequent reactions
🗑
|
||||
| What is fed-batch culture? | Limited amounts of nutrients are added at regular intervals to keep the culture alive and prolong the stationary phase, used to produce secondary metabolites
🗑
|
||||
| Why is glucose added to a culture? | Carbon source, respiratory substrate
🗑
|
||||
| What are the disadvantages of using microorganisms in biotechnology? | Fermenters can become contaminated, high cost of downstream processing
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
11043
Popular Biology sets