biology unit 1 summary notes
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?- Created by: studywolf1
- Created on: 15-05-16 14:05
Diet, exercise and Health
A healthy diet
we need to eat food for three reasons:
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For growth and repair
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For energy
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To keep us healthy
Food is made out of five main groups: carbohydrates, fats, proteins, mineral ions, and vitamins.
Food/nutrient
Why you need to eat it
Sources
Carbohydrates
For energy
Bread, pasta, rice, sugary food
Fats
For energy
Butter, cheese, fried food
Proteins
To build cells and repair tissue
Meat, fish, cheese, nuts
Mineral ions and vitamins
Needed in small amounts to keep the body healthy
Fresh fruit and vegetables
A healthy body is a balanced one with the right amount of foods and energy to match the body’s needs.
A balanced diet- a diet that has the right amount of proteins, fats, carbohydrates, vitamins, minerals, water, and fibre and gives you enough energy.
Malnourishment
A person is malnourished if their diet is not balanced. There are two main types of malnourishment:
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Being underweight- this occurs when people eat too little or exercise too much. Their diet has too little food or energy and they lose body mass.
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Being overweight- this occurs when people eat too much or exercise too little. Their diet will contain too much food or energy for their needs and the gain body mass.
The body lacking some food groups, such as vitamins or minerals, can be an effect of malnourishment. This can lead to deficiency diseases, for example, rickets, caused by a lack of vitamin D.
vitamin
Name of deficiency
symptoms
Sources of vitamin
Vitamin C
Scurvy
Bleeding and swelling of the gums, loss of teeth, tiredness, muscle and joint pain
Citrus fruits, leafy green veg
Vitamin D
Rickets
Bone pain
Eggs, oily fish
Vitamin A
Night blindness
Difficult to see in dim light
Dairy products, oily fish
Calcium
Weak bones and teeth, poor clotting of blood, muscle spasms
Cheese, eggs, milk, green leafy veg
Iron
Anaemia
Tired, weak, blood doesn’t transport enough oxygen
Liver, red meat, beans, nuts, dried fruits
Dietary Fibre
constipation
Fruit, vegetables, cereal
Metabolic rate
Metabolism- all the chemical reaction going on in cells.
Metabolic rate- the rate at which the chemical reactions in your body occur.
Factors that affect metabolic rate:
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Exercise – the more you exercise, the more reactions, like respiration, occur in the cells, so the metabolic rate is higher.
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Proportion of muscle to fat – more muscle and less fat in the body will increase the metabolic rate because reactions occur in the muscle. The more muscle the higher the metabolic rate.
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Genetic – people inherit factors that will increase their metabolic rate. For example, tall people have a higher metabolic rate.
Disease and medicine
Pathogens
Pathogen- microorganism that can cause infectious disease.
Bacteria and viruses may reproduce rapidly inside the body and may produce poisons, toxins, that make us feel ill.
Viruses:
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Are much smaller than bacteria
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When viruses get into our body they need to get into our cells. There they will reproduce rapidly and…
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