Biotechnology and genetic modification.

why bacteria are useful in biotechnology and genetic modification,

• presence of plasmids

• there is few ethical concerns over their manipulation and growth

• their rapid reproduction rate

• their ability to make complex molecules

yeast anaerobic respiration

C6H12O6 → 2C2H5OH + 2CO2 (exothermic)

ethanol - for biofuels

CO2 - for the rise of dough in bread

make biofuels with yeast

plants are mixed with yeast. the yeast turns the plants into ethanol by undergoing anaerobic respiration.

make bread with yeast

Yeast is mixed with sugar, water and flour.

When the yeast undergo anaerobic respiration carbon dioxide and ethanol are produced.

The carbon dioxide gets trapped in the dough, creating bubbles.

This causes dough to rise.

This gives bread its airy texture.

pectin

pectinase (enzyme)

Pectin is located in plant cell walls.

gives fruits their thickness and makes them difficult to squeeze.

pectinase is a enzyme that breaks down pectin. this helps make it simpler and easier to extract juice from the fruit. This speeds up juice extraction, and makes juice clearer. The pectin is converted or broken down into monomer sugars, so the juice is sweeter

lactase use

used to make lactose free milk.

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when added to milk, lactase breaks down the lactose in the milk, turning it into simpler sugars (glucose and galactose) which are easier to digest. this makes the milk suitable for people who are lactose intolerant

fermenter products that are useful

mycoprotein - made using fungi. protein-rich food source used as a meat alternative for vegans

insulin - made using bacteria. it helps people with type 1 diabetes since it helps regulate and lower blood sugar levels

penicillin - made using the fungus penicillium. it is an antibiotic that fights bacterial infections. it works by stopping bacteria from growing or killing them.

conditions controlled in a fermenter

temperature - ensure optimum temperature to increase enzyme activity

pH - provide an optimum pH for enzyme activity

oxygen - needed for aerobic respiration

nutrient supply - nutrients are needed for use in respiration to release energy for growth and to ensure the microorganism are able to reproduce.

waste products - too much waste can stop microorganisms from growing and making products. getting rid of waste is important to ensure the microorganisms are healthy. waste is toxic. Fermenter is cleaned by steam to kill microorganisms and prevent chemical contamination, which ensures only the desired microorganisms will grow

Agitation: Stirring paddles ensure that microorganisms, nutrients, oxygen, temperature and pH are evenly distributed throughout the fermenter

Advantage of fermenters: Conditions can controlled, can produce large amounts of products.

describe how bacteria are used to produce enzymes

• Bacteria grown in fermenters

• Bacteria provided with nutrients and glucose

• Provided with oxygen and are in aerobic conditions

• Bacteria reproduce

• Enzymes secreted

• Enzymes separated from bacteria or mixture

Why stir in a fermenter

So uniform distribution/concentration of contents

Prevent clumping or setlling of contents

So oxygen/glucose/nutrients dissolve

So that bacteria can absorb substances more easily

biological washing powder enzymes

protease - to break down proteins to remove blood stains and food stains.

lipase - to breaks down fats and oil to remove grease stains

these products are soluble and washed away in the water

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good at removing stubborn stains

work well in lower temperatures resulting in energy savings since it doesn’t require high temperatures

genetic modification

changing the genetic material of an organism by removing, changing or inserting individual genes

bacteria production of a human gene

• The gene that is to be inserted is located in the original organism

• Restriction enzymes are used to isolate the required gene, leaving it with ‘sticky ends

• A bacterial plasmid is cut by the same restriction enzyme leaving it with complementary sticky ends

• The human DNA is inserted into the bacterial plasmid DNA using DNA ligase to form a recombinant plasmid

• The recombinant plasmid is inserted into a bacterial cell

• The bacteria divides rapidly with the recombinant plasmid

• expression in bacteria of the human gene to make the human protein

advantage of asexual reproduction for bacteria in biotechnology

• Rapid process.

• Large quantity of (substance) produced

• Cheap

• All bacteria have same (insert) gene

• No gametes

Discuss the disadvantages of genetically modifying crops, including soya, maize and rice

• Seeds are expensive. Poor farms can’t compete with larger farms.

• Needed to be bought every season

• Risk of cross pollination with wild plants

• Reduces natural biodiversity

• insect-resistant plants negatively affect pollinators

• ethical concerns of consumers

Discuss the advantages of genetically modifying crops, including soya, maize and rice

Genes are inserted into crop plants to confer resistance to herbicides and disease. This improves crop yield. Genes are inserted into crop plants to confer resistance to insect pests. This reduces the usage of chemicals such as insecticides, which is better for the environment less pollution, less money spent on insecticids, less risk of eorker’s health by insecticides.

Insertion of genes into crop plants to improve nutritional qualities, such as golden rice have beta-carotene. Preventing night blindness.

examples of gene insertion

• (a) The insertion of human genes into bacteria to produce human proteins

• (b) The insertion of genes into crop plants to confer resistance to herbicides

• (c) The insertion of genes into crop plants to confer resistance to insect pests

• (d) The insertion of genes into crop plants to improve nutritional qualities