UNIT 21: BIOTECHNOLOGY
Bacteria are useful in biotechnology and genetic engineering because
Ability to make complex molecules
Rapid reproduction rate
Lack of ethical concerns over their manipulation and growth
Genetic code shared with all other organisms so we can take a gene from a
human cell and place it into a bacterial cell, and it will work to produce human
proteins
Presence of plasmid, easy to transfer from one cell to another
Yeast and production of ethanol for biofuels
Fermentation (anaerobic respiration): glucose -> ethanol + carbon dioxide
1. Maize is treated with amylase enzymes to break stored starch to glucose
2. Yeast is added to use glucose for fermentation and produce ethanol
3. Ethanol is extracted from the mixture by distillation
4. Mix with gasoline so it contains more energy per litre
Yeast in bread-making
1. Flour (contain starch, protein – gluten) is mixed with water and yeast to
make dough
2. Amylase breaks down starch to make maltose and glucose so yeast can
respire anaerobically
3. Gluten makes the dough stretchy so carbon dioxide bubbles can make the
dough rise
4. Alcohol is broken down when the bread is baked, alongside with yeast
Biological washing powders
Catalyse breaks down protein molecules – remove stains caused by protein
(blood stain)
Proteases break down haemoglobin molecules into smaller molecules which are
colourless and dissolve easily in water
Lipases break down fats -> remove greasy stain
To prevent enzymes from digesting proteins and fats in the skin, the enzymes
are packed into microscopic capsules which break open when mixed with
water
Pectinase in juice production
Pectin helps to stick plant cell together
If pectin is broken down, it can be much easier to squeeze juice from the fruit
Widely used commercially both in the extraction of juice from fruit and in making
the juice clear
Lactase in producing lactose-free milk
Bacteria are useful in biotechnology and genetic engineering because
Ability to make complex molecules
Rapid reproduction rate
Lack of ethical concerns over their manipulation and growth
Genetic code shared with all other organisms so we can take a gene from a
human cell and place it into a bacterial cell, and it will work to produce human
proteins
Presence of plasmid, easy to transfer from one cell to another
Yeast and production of ethanol for biofuels
Fermentation (anaerobic respiration): glucose -> ethanol + carbon dioxide
1. Maize is treated with amylase enzymes to break stored starch to glucose
2. Yeast is added to use glucose for fermentation and produce ethanol
3. Ethanol is extracted from the mixture by distillation
4. Mix with gasoline so it contains more energy per litre
Yeast in bread-making
1. Flour (contain starch, protein – gluten) is mixed with water and yeast to
make dough
2. Amylase breaks down starch to make maltose and glucose so yeast can
respire anaerobically
3. Gluten makes the dough stretchy so carbon dioxide bubbles can make the
dough rise
4. Alcohol is broken down when the bread is baked, alongside with yeast
Biological washing powders
Catalyse breaks down protein molecules – remove stains caused by protein
(blood stain)
Proteases break down haemoglobin molecules into smaller molecules which are
colourless and dissolve easily in water
Lipases break down fats -> remove greasy stain
To prevent enzymes from digesting proteins and fats in the skin, the enzymes
are packed into microscopic capsules which break open when mixed with
water
Pectinase in juice production
Pectin helps to stick plant cell together
If pectin is broken down, it can be much easier to squeeze juice from the fruit
Widely used commercially both in the extraction of juice from fruit and in making
the juice clear
Lactase in producing lactose-free milk
