Module 2- Food and Health Flashcards
Define Nutrition.
Nutrition is nourishment- the nutrients and energy needed for health and growth.
Define a Balanced diet?
A balanced diet is one that contains all nutrients required for health in appropriate proportions.
Define Obesity.
Obesity is when a person is 20% or more heavier than the average weight for their height.
What are the 7 components to a balanced diet?
Carbohydrates, Proteins, Fats, Vitamins, Minerals, Water and Fibre or Roughage.
What is the purpose of carbohydrates?
Carbohydrates are our main source of energy.
What are Proteins used for within the body?
These are essential for growth and repair of muscle and other body tissues.
What are Fats used for within the body?
These are essential as a source of energy and are also important in cell membranes waterproofing, absorption of fat-soluble vitamins and many other roles.
What are Vitamins used for within the body?
These play an important role in the chemical processes taking place inside cells. Some are water-soluble and some fat-soluble.
What are Minerals used for within the body?
These are inorganic elements occurring in the body that are essential to its normal functions.
What is Water used for within the body?
This is essential to body function. It is used in transport in substances around the body and as main component of the body. About 60% of the human body is water.
What is Fibre used for within the body?
This is the indigestible part of our food, and is essential for healthy functioning of the digestive.
How does Obesity occur within the body?
Obesity is caused by consuming too much energy. This excess energy is deposited as fat in the adipose tissues.
At what point are you considered clinically obese?
When you have a BMI of over 30.
How do you calculate Body Mass Index (BMI)?
Mass in kg/ Height in m^2
Name 6 health risks caused by Obesity.
Cancer, Cardiovascular Disease, Type 2 diabetes, Gallstones, Osteoarthritis, and High Blood pressure (Hypertension).
What components of the diet are said to help reduce the risk of CHD?
Dietary fibre, moderate alcohol consumption and eating oily fish all seem to be beneficial.
Name three components of the diet that increase the risk of CHD.
Salts, Fats (lipids) and Cholesterol.
Explain how excess salt in your diet increases your risk of developing CHD
Excess salt in your diet will decrease the water potential of your blood. As a result more water is held in the blood and blood pressure increases. This can lead to Hypertension- which can damage the inner lining of the arteries which is an early sign of atherosclerosis.
Explain how excess fat in your diet increases your risk of developing CHD.
Animal fats tend to be saturated and plant fats tend to be unsaturated. Having too many saturated fats in your diet increases the risk atherosclerosis through the deposition of fatty substances in the arterial linings.
Explain how excess cholesterol in your diet increases your risk of developing CHD.
Cholesterol is found in many foods and is often associated with saturated fats in meat, eggs and dairy products. High blood cholesterol has been linked to 45-47% of deaths from coronary heart disease.
What should the concentration of cholesterol in the blood be?
The concentration of cholesterol in the blood should be maintain BELOW 5.2mmmol dm
Define lipoproteins.
Lipoproteins are a combination of lipid, cholesterol and protein used to transport fats and cholesterol around the body.
How many types of lipoprotein are there?
High density lipoprotein (HDL), and Low density lipoprotein (LDL).
What is HDL produced by?
HDLS are produced by the combination of unsaturated fats, cholesterol and protein.
What is LDL produced by?
LDLs are produced by the combination of saturated fats, cholesterol and protein.
How do saturated fats affect LDL receptors?
Saturated fats are thought to decrease the activity of the LDL receptors. Therefore as LDL blood concentration rises, less is removed from the blood. This results in a higher concentration of LDL in the blood and it is deposited in the artery walls.
How do Polyunsaturated fats affect LDL receptors?
Polyunsaturated fats seem to increase the activity of the LDL receptors and so decrease the concentration of LDL in the blood.
How do Monounsaturated fats affect LDL receptors?
Monounsaturated fats also seem to help remove LDLs from the blood.
What balance needs to be kept in order to maintain a healthy level of lipoproteins in the body?
Since LDLs are associated with greater deposition in the artery walls it is important to maintain a low levels of the low density lipoproteins. HDLs are associated with a reduced deposition so it is best to maintain a high proportion of these in the blood.
What will eating a lot of saturated (animal) fats do to the levels of lipoproteins in your blood?
Eating these saturated fats will increase the level of LDLs.
What affect will eating a low-fat diet do to overall lipoprotein levels in the blood?
This will reduce the overall lipoprotein levels in the blood.
What effect will eating a high proportion of unsaturated fats have on the level on lipoproteins in the blood?
It will cause there to be an increase in the HDL lipoproteins in the blood.
Define Selective Breeding.
Selective breeding is where humans select the individual organisms that are allowed to breed according to chosen characteristics.
Define Fertilisers.
Fertilisation are mineral needed for plant growth, which are added to the soil to improve its fertility.
Define a pesticide.
A pesticide is a chemical that kills pests.
Define a fungicide.
A fungicide is a chemical that kills fungi.
Define an Antibiotic.
An antibiotic is a chemical that kills or prevents reproduction in bacteria.
Give some examples of marker-assisted selection.
Tomatoes have been bred with improved disease resistance to yellow leaf curl virus, this was bred in from a wild tomato variety by the identification of the allele responsible.
Apple have also been bred to this effect, also improving flavour and texture.
Some examples of selective pressure.
Farmers breed cattle for high milk yield or meat production. Dairy cows can produce over 40 litres of milk a day.
Farmed salmon have been selected to grow more quickly so the time-to-market has been cut by 30%.
Name three ways in which we as humans can make food production in animals more efficient.
In animals it is possible to improve the rate of growth, increase productivity and increase resistance to disease.
Name five ways in which we, as humans, can make food production in plants more efficient.
Improve the growth rate of crops, Increase the size of the yield from each plant, reduce losses of plants due to disease and pests, make harvesting easier by standardising plant size and improve plant response to fertilisers.
Explain the difference between natural and artificial selection.
Natural selection is the selection of particular varieties that are well adapted to the environment . They are selected by environmental forces or pressure. Artificial selection is selection by humans to achieve an exaggeration of certain features.
