use & growth of organisms Flashcards
define ‘biotechnology’
applying biological organisms to the synthesis, breakdown or transformation of materials in the service of people
what are the most commonly used microorganisms is biotechnology?
fungi
- particularly yeast & bacteria
why are microorganisms used in biotechnology?
- no welfare issues, only optimum conditions need to be considered
- range of organisms capable of carrying out chemical reactions
- genetic engineering allows us to manipulate organisms to produce things such as insulin
- short life cycle and rapid growth rate
- nutrient requirements cheap & simple
- conditions for microorganisms to grow are low temp - cheap
what is indirect food production?
the actions of the micro organisms on other foods is important
- eg making bread/cheese
what are the disadvantages of indirect food production?
- conditions must be ideal for micro organisms to work/grow properly
- could cause food to go off / cause disease so conditions must be sterile
- ethical issues of genetic engineering
what type of micro organism is involved in baking?
yeast
what are the main stages of baking?
- active yeast added to other ingredients, left to rise
- dough knocked back & kneaded
- cooked in hot oven, carbon dioxide bubbles expand and yeast cells killed
what type of micro organism is involved in brewing?
yeast - respires anaerobically to produce ethanol
what are the main stages of brewing?
- malting = enzymes produced by barley break down starch into sugars, seeds killed by slow heating but enzymes retained to produce malt
- mashing = malt mixed with hot water, enzymes break down starch to wort, wort is sterilised and cooled
- fermentation = wort is inoculated with yeast, yeast inhibited by falling pH, ethanol build up and lack of oxygen
- beer is filtered and pasteurised
what type of micro organism is involved in cheese making?
bacteria
- feed on lactose in milk
- inhibits growth of bacteria which makes milk go off
what are the main stages of cheese making?
- milk is pasteurised and homogenised
- mixed with bacterial cultures until milk separates
- strained through moulds / cheesecloth
- left to mature, dry & ripen
what type of micro organism is involved in yoghurt making?
bacteria
- from ethanal and lactic acid
- produces extracellular polymers to give smooth texture
what are the main stages of yoghurt making?
- milk powder added to milk, pasteurised & homegenised
- milk mixed with bacteria and incubated
- mixed and fermented
what is direct food production?
using micro organisms to produce proteins you eat
foods produced in direct food production are known as …. …… …..
single cell protein
what is quorn made from?
a single celled fungus grown in large fermenters using glucose syrup as a food source
describe how quorn is produced
microorganisms combined with egg white, compressed and formed into meat substitutes
what do humans increasingly use SCP for?
- yeast, algae and bacteria are used to grow proteins
- single cell proteins to feed animals that we prefer to eat
how is penicillin produced?
- by mould/fungus
- fungus is grown in fermenters, stirred with oxygen and nutrients and then purified
how is insulin produced?
- by GM bacteria
- using a human insulin gene and plasmids
what is bioremediation?
- micro organisms are used to digest pollutants / contaminants eg sewage
- encourages microbial growth
- increased population size to break down pollution
state 5 advantages of using microorganisms
- microbes grow rapidly
- can be GEd
- flavoured to taste
- no ethical concerns
- rich in protein, low in fat
state 3 disadvantages of using microorganisms
- can produce toxins if growing conditions aren’t controlled
- conditions must be aseptic
- no natural flavour, requires additives
describe the growing conditions for culturing microorganisms
- growth medium (agar) with water and nutrients
- requires oxygen
- incubates at 25 degrees for growth and avoid pathogen growth
- aseptic to prevent contamination
describe what is meant by aseptic conditions
- sterilise equipment
- sterilise surface
- wash hands
- work near bunsen burner
- petri dish only slightly open and when necessary
