Pre and Probiotics
Prebiotics and probiotics are both sources of bacteria, in this case it is the good bacteria, and they stimulate the growth of useful bacteria in the colon. They are non-digestible functional foods. They are marketed as providing health benefits because prebiotics stimulate ‘beneficial bacteria’ (Lactobacillus and Bifidobacterium), these are naturally found in the human gut, the growth and development of beneficial bacteria results in health benefits.
Oligosaccharides are an added sugar that is added to prebiotics; these feed the good bacteria and make them multiply.
1. Milk is used to sterilise it, killing any bacteria already present.
2. Then the milk is stirred thoroughly to mix up its ingredients and milk protein is added.
3. A starter culture of lactobacillus bacteria is added to the milk.
4. The lactobacillus bacteria ferment the sugar lactose in the milk into lactic acid while it’s warm.
5. The lactic acid lowers the pH of the milk (the milk becomes acidic) to the point where the milk proteins coagulate.
6. The raw yoghurt is cooled quickly.
The yoghurt has been changed from lactose into lactic acid using lactobacillus bacterium.
Soy Sauce Production
Soy sauce production:
1. Soya beans are cooked, which kills all of the bacteria on their surface, and mixed with ground roasted wheat.
2. Asperguillus mould is added to the mixture.
3. The mixture is spread out on warm shallow trays and supplied with air.
4. Enzymes produced by the asperguillus mould catalyse the breakdown of proteins and carbohydrates in the mixture.
5. The amino acids and sugar content of the mixture increases.
6. Brine (sodium chloride solution) is added to the mixture (salty taste)
7. Yeasts and lactobacillus bacteria, which are able to tolerate high levels of sodium chloride and low levels of oxygen, are added to the brine mixture. The conditions stop the activities of the asperguillus mould.
8. The sugars in the mixture are fermented by the yeasts and lactobacillus bacteria
9. Raw soy sauce is drained from the mixture.
10. The liquid is filtered and cleared of any sediment (filtration).
11. The filtered and cleared liquid is heated to 72oC (pasteurisation) and stored to allow its flavours to develop.
12. It is then placed in sterilised bottles ready for sale.
Describe the production of the enzyme chymosin, produced by the genetically altered microorganisms.
Chymosin is made using GM bacteria; the Chymosin made using bacteria contains fewer impurities and is acceptable to vegetarians. The cheese made using GM chymosin is itself rated GM free because it is non-made using GM organisms, even though the enzymes used in production by GM organisms.
Recall that chymosin is used in the manufacture of vegetarian cheese.
The cheese made using GM chymosin is itself rated GM free because it is non-made using GM organisms, even though the enzymes used in production by GM organisms.
Microbial Products used in Food
Citric acid it added to fizzy drinks, sweets and jams. It enhances the flavour of food.
It also prevents the breakdown of vitamin C in food.
The mould fungus asperguillus niger is used to produce citric acid.
Monosodium Glutamate (MSG):
Monosodium glutamate is a salt that enhances the flavour of food. It is particularly popular in Chinese food.
The bacterium coryne bacterium glutamicum is used to produce the amino acid glutamic acid.
Neutralisation of the acid makes a sodium salt called monosodium glutamate (MSG).
Different species of the bacterium acetobater are used to produce vitamin C.
The process is a fermentation reaction.
Well Balanced Diet
A well-balanced diet.
The importance of having a balanced diet (a balanced diet is one that contains proportional amounts of the food groups to give the eater the daily amounts of nutrition they need) is because it makes you more likely to be healthy and be in better physical fitness.
Obesity may lead to a number of health problems.
Obesity may lead to health problems as the constant abuse to your body could clog up major blood vessels such as your coronary artery which can lead to a heart attack, also it can lower the amount of oxygen in your blood which could go as far as giving you a stroke.
Under Eating may lead to a number of health problems.
Under-eating at any weight has a marked effect on physical health. It can lead to heart and circulation problems, digestion problems, infertility and affects your skin and hair.
Traditional breeding programmes:
1. Farmers carry out plant breeding programmes by cross breeding them with other plants to make a hybrid e.g. red peppers & yellow pepper mixing to make a hybrid.
The desirable characteristics that are bred into plants are better taste, colour, shelf life, yield, size and pest resistance.
The major disadvantage of traditional plant breeding programmes is that it takes 10 years to make.
Genetic engineering is when you modify the genes so it can help something grow it is more beneficial to farmers because it takes less time to work.
Genomics is the knowing of all the genes in the human body (working out sequence). This was found out through the Human Genome Project (HGP). The human genome took approximately 13 years to complete, running from 1989 to 2003; this piece of scientific research has helped dramatically as people are able to help treat genetically inherited diseases like diabetes easier as they know where the gene is in the body.
The method of the Human Genome Project is:
1. Samples of cells were taken from anonymous volunteers.
2. The chromosomes of the cells were broken up into pieces to get their DNA.
3. Thousands of copies of the pieces of DNA were made, enough material to work on.
4. The DNA was then placed inside machines called sequencers, and the most probable order of bases displays on a computer screen.
Old and New Medicines
Describe the role of biotechnology in developing new medicines – genomics.
The use of biotechnology in creating medicine is to ‘personalise’ drugs to suit an individual’s genetic makeup, this would make a drug more successful as it is personalised and will be able to treat whatever is needed to be treated better.
Describe the importance and medicinal value of drugs produced by plants.
The importance of drugs produced by plants is huge, for example curare in modern surgery is that they are included in anaesthetics to help control your breathing while you undergo surgery. Early man used curare for hunting and put it on their darts which suffocated their prey will fall out of the trees.
Name Found Treats
Quinine Cinchona tree Malaria
Taxol Yew tree Diseases such as Parkinsons' disease
Aspirin Willow tree Fever/swelling/blood clotting
Artemisinin Artimisia Malaria
Explain that allowing people to choose the sex if their baby may skew the sex balance of the population.
Choosing the sex of babies for genetic reasons could affect the population balance as there is roughly 50:50 balance and choosing the sex would favour girls as genetic disorders come from the male side.
Explain that allowing people to choose the sex of their baby may lead to other choices being permitted e.g. eye colour.
Choosing a baby’s features is called a designer baby and allowing people to choose the sex of their baby could encourage this behaviour, which is not a good thing. This is because it will firstly cost a lot of money to do this and also it will cause a lot of waste and there will be less natural babies.