C3 Revision notes

Key notes to memories for C3- OCR 21st Century

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  • Created on: 24-06-12 10:54
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C3 Food Matters
Most of the food we eat is produced by intensive farming, but an increasing proportion is
produced by organic farming. If farmers in the UK want to claim that their products are
organic, they have to follow UK national of agriculture use synthetic fertilisers. These contain
nutrients that have been made in factories.
Farmers using organic methods use manure, which is the waste material from animals such as cows.
Both synthetic fertilisers and manure contain the essential nutrients needed for crops to grow well.
Farmers using organic methods may also use crop rotation. In a field they grow a plant that puts
nutrients into the soil, for example the leguminous plant, clover, and then the next year they grow a
crop that uses these nutrients. This cycle is repeated to ensure that the nutrients in the soil are not
Pests and diseases
If crops are attacked by pests or diseases their yields are reduced.
Intensive farming
Spraying a crop of oil seed rape with insecticide
Farmers using intensive methods of agriculture combat
pests and diseases by spraying their crops with chemicals
that kill the pests or disease organisms. These chemicals
are synthetic compounds produced by the chemical
However, some of the chemicals used by these farmers may also kill helpful insects such as bees.
Furthermore, the chemicals may get into water supplies or food chains, harming wildlife.
Organic farming
Farmers using organic methods use other ways to combat pests and diseases.
These include:
spraying natural chemicals obtained from plants onto their crops
picking pests such as caterpillars off the plants by hand
placing natural predators of the pests onto the crops
growing, amongst the crops, other plants that repel insect pests
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The methods used in organic farming are likely to cause less damage to the environment than the
synthetic chemicals used in intensive farming.
Developments in food production may have a significant effect on our lives. Scientific research
and applications, including those involved with agriculture, are controlled by official
regulations and laws.
Benefits and costs
The methods used in farming affects different groups of people in different ways. Some may benefit
from a particular course of action, while others may not. Here are two examples.…read more

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Manufacturers use food additives to create products that people want to buy. They may also
increase how long the food will last.
There are several types of food additive, each used in food for a different purpose.
These may be used to replace the natural colours lost as the food was processed. They may also be
used to add colour to make the food product look more attractive. People buy food that looks nice.…read more

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Flavourings do not have E numbers, but they are controlled by other laws.
Contamination and cooking
Mould and bacteria may grow in food if it is not stored correctly. Some release toxic chemicals as
they grow.
Aflatoxins are produced by moulds growing on nuts and dried fruit. These chemicals can cause
It is also possible for toxic chemicals to be made as some foods are cooked.
Cooking starchy foods at a high temperature may produce acrylamide, which may cause cancer.…read more

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Amino acids
Cells grow by building up amino acids from the blood into new proteins.
These parts of the body are made mainly from protein:
haemoglobin (in blood)
Excess amino acids are broken down in the liver to form urea. This is excreted by the kidneys in urine.
People with diabetes cannot control blood glucose concentration properly. Type 1 diabetes is
treated using insulin injections, and type 2 diabetes is controlled through diet and exercise.…read more

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It is important that the concentration of glucose, which is a type of sugar, in the blood stays at a near
constant level. There are serious consequences if blood sugar concentration goes outside a narrow
The consequences are that:
too little glucose causes confusion, unconsciousness, even coma
too much glucose causes exhaustion and blurred vision
Processed foods often contain a lot of sugar. This is absorbed easily in the digestive system, causing
a rapid increase in the blood glucose level.…read more

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Eating a poor diet and being obese both increase the risk of developing type 2 diabetes. Despite this
increased risk, many people continue to eat poorly and many people are obese.
Eating a poor diet increases the
risk of developing Type 2
Personal choices
People make personal choices in
terms of balancing the risks and
benefits of their activities.
What people eat, and how heavy
they become, are the result of personal choices. Many people enjoy eating junk food.…read more


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