B6 - Understanding Bacteria

Understanding bacteria

• Why do bacteria have flagella?
• Write down the name of a chemical that bacteria can use to make food.
• When making yoghurt, milk is first heated to 95oC. Suggest why.
• Describe one example of good practice when using bacteria.

Genetic Engineering

• Describe the stages involved in creating a transgenic organism.
• What are restriction enzymes used for?
• Which type of organism is genetically engineered to make insulin?
• Suggest one disadvantage to growing plants resistand to weed killers.

Understanding bacteria

• To help the move.
• Hydrogen sulphide or ammonia.
• To kill any unwanted bacteria already in the milk.
• Wash hands before/after handling bacteria, disinfect working areas, sterilise all equipment before/after use, don't leave lids off containers.

Genetic Engineering

• Identify the gene needed and remove it from the DNA; cut open the DNA in another organism; add the gene to the DNA of that organism; this is now a transgenic organism; clone the transgenic organism.
• Cut open the DNA.
• Bacteria
• The resistance could pass to plants in the environment making it more difficult to kill them

Harmful microorganisms

• Describe how you could become infected with the dysentery pathogen.
• Which two bacteria cause food poisoning?
• Write down the name of the first antiniotic.
• Explain why loss of electrical supplies could cause food poisoning.

Microorganisms

• Write down the word equation for fermentation.
• Yeast grown to make alcohol isnot given oxygen. Explain why.
• Describe how the alcohol concentration of a drink can be increased.
• How can wines be made with different flavours?

Harmful microorganisms

• Drinking contaminated water.
• Salmonella and E.Coli
• Penicillin
• Food cannot be kept cold, so decays faster.

Microorganisms

• Sugar = alcohol+carbon dioxide+energy
• To stop the yeast carrying out aerobic respiration and not make any alcohol.
• Distillation, heating the drink to evaporate the alcohol then cooling the alcohol to collect it.
• By using different strains of yeast.

Biofuels

• Why is the method of making methane called continuous flow method?
• Digesters must be kept below 45oC. Explain Why.
• Describe how biogas can help a central heating system.
• Biofuels may help reduce the greenhouse effect. Explain why.

Life in soil

• Earthworms burrow into the soil. Explain why this improves the soil.
• Why did Darwing believe earthworms were so important to soil?
• Earthworms are detrivores; name another detrivore that lives in soil.
• What is the job of Azotobacter in the nitrogen cycle?

Biofuels

• Because it caries on without stopping for a long time, methane is taken out continuously not just in one go.
• Above 45oC enzymes denature and bacteria die.
• Heats water and produces steam.
• Biofules do not increase atmospheric levels of carbon dioxide and growing the plants may help to reduce levels.

Life in soil

• It aerates the soil and improves drainage.
• Earthworms mix up the layers; this results in  a deeper layer of fertile soil.
• Millipedes or springtails.
• Convert nitrogen from the air and use it in their own proteins.

Microscopic life in water

• What advantages does living in two habitats give to frogs?
• When does a salmon actively transport saly into its body?
• Caddis fly larvae are not found in polluted water. Suggest a reason why.
• Algal blooms are more common when there is more light. Explain why.

Enzymes in action

• Which group of enzymes are needed to remove protein stains?
• What are the products when sucrase breaks down sucrose?
• Write down two advantages of using immobilised enzymes.
• What are the products when lactase breaks down lactose?

Microscopic life in water

• Reduces the competition for food between young and adult.
• When it swims in fresh water.
• Not enough oxygen for them to survive.
• Algae have more light energy for photosynthesis.

Enzymes in action

• Proteases.
• Glucose and frutcose.
• Immobilised enzymes are easier to seperate from the solution and they do not contaminate the product.
• Glucose and galactose.