Food Production Flashcards
Glasshouses
Artificial heating - enzymes controlling photosynthesis can work faster at higher temperatures
Artificial lighting - allows plants to photosynthesise for longer
Increasing carbon dioxide - allows plants to photosynthesise quicker
Regular watering - photosynthesis
ventilation is needed in country’s with hotter temperatures so that enzymes don’t denature
Polythene tunnels
Large plastic tunnels that cover crops from the weather
- Slightly increases temperature inside the tunnel
- Prevents entry of pests which could damage plants
Factors that limit the rate of photosynthesis
Temperature
Light intensity
CO2 concentration
Crop Plants: Fertilisers
It increases the amount of key nutrients in the soil for crop plants increasing yield
How do fertilisers increase crop yields?
Fertilisers replace the mineral ions from the soil to make crops grow faster and bigger so yield is increased
Types of fertilisers
Nitrogen -
Absorbed in the form of nitrates, makes amino acids which are building blocks for proteins, lack of nitrogen causes weak growth and leaves to become yellow
Phosphorus - absorbed in the form of phosphates, needed to make DNA and cell membranes, lack of phosphorus causes poor root growth and discoloured leaves
Potassium - absorbed in various of compounds of potassium, allows enzymes reactions to take place e.g to make ATP in respiration and needed for enzymes involved in photosynthesis
Types of pesticides
Insecticides - kills insect pests
Herbicides - kills plant pests
Fungicides - kills fungal pests
Advantages of pesticides
- Easy access and cheap
- Has an immediate effect
- Kills the entire population of pests
Disadvantages of pesticides
- Organisms can build resistance to them
- Non-specific chemicals can often kill other beneficial organisms
- They can be persistent chemicals
Biological control
Using animals to eat pests, although it doesn’t completely remove a pest, it keeps it at lower levels
Advantages of biological control
- Natural method - no pollution
- No resistance
- Targets specific species
- Long lasting
Disadvantages of biological control
- May eat other organisms instead of the pest
- Long period of time to be effective
- Cannot kill entire population
Yeast in Food production
When making bread, yeast is added to bread dough. The yeast produces enzymes which breaks down the starch releasing glucose which is used in aerobic respiration.
Becomes anaerobic when oxygen runs out which then produces ethanol and CO2. CO2 is then trapped into small air pockets in dough causing dough to rise.
Bread doesn’t have alcohol since when put in an oven, the ethanol produced by yeast is evaporated due to yeast.
Investigating Anaerobic Respiration in Yeast
C - Changing the temperature
O - Type of yeast must be the same
R - repeat investigation
M - Measure the number of bubbles
M - Time period (e.g 2 mins)
S - Control the ph of the sugar solution
Role of Bacteria
Industrial Fermenters
Used to grow microorganisms like bacteria and fungi in large amounts e.g beer or yoghurt
Conditions in an industrial fermenters
Fish Farming advantages
- Ability to selectively breed (high quality and fast-growing fish)
- Protect against predators
- Control water quality
Fish farming methods
- Maintaining water quality to prevent diseases
- Fish are same size and age so they don’t eat each other
- Quality of food (high in nutrients)
