Food and Health

Question 0

What are the seven components of a balanced diet?

Answer 0

Carbohydrates - main source of energy
Proteins - growth and repair (muscle and body tissue)
Fats - essential for energy, used in cell walls, waterproofing, absorption of fat soluble vitamins and much more
Vitamins - used in chemical processes ( fat or water soluble)
Minerals - inorganic elements essential to our functions
Water - transport, chemical reactions, solvent etc.
Fibre (or roughage) - indigestible part of food. Essential for healthy digestive system.

Question 1

Why do we eat a balanced diet with good nutrition?

Answer 1

To:

• Provide better health
• Ensure a stronger immune system
• Ensure you become ill less often
• Help you learn more effectively
• Make you stronger
• Make you more productive

Question 2

What is obesity and why is it a problem?

Answer 2

Obesity is a form of malnutrition caused by consuming too much energy, the excess of which is deposited as fat. It is usually a BMI of over 30 (20% more body fat than recommended per hight. Many more people are obese in developing countries. males rose from 6% to 25 % of them being obese and for women it was 8% in 1980’s and now is 20%.

Question 3

What can be caused by obesity and what is it linked to?

Answer 3

It can cause :
    - Cancer
    - Cardiovascular disease
    - Type 2 diabetes
It is linked to:
    - Gallstones
    - Osteoarthritis
    - High blood pressure

Question 4

How an a diet high in salt contribute to CHD?

Answer 4

Excess salt can increase water potential of blood, so more water is held in the blood, and blood pressure increases. This can lead to hypertension, where blood pressure (particularly diastolic) is maintained at a to higher level. it can damage the inner artery lining which can lead to atherosclerosis (Where fatty substances are deposited on the coronary arteries). This causes coronary heart disease.

Question 5

How would fats contribute to CHD?

Answer 5

Increase in saturated fats ( Mostly animal fats) can increase the fats that can be deposited in the coronary arteries, causing atherosclerosis which can lead to Coronary heart diseases.

Question 6

How does cholesterol increase the chances of CHD?

Answer 6

It has similar properties to a triglyceride and is associated with saturated fats in animal produce and is made in the liver from saturated fats. Too higher concentration of cholesterol can be harmful and increase the chance of CHD

Question 7

What is a lipoprotein?

Answer 7

Tiny balls of fats that combine with a protein and to transport lipids (I.e. cholesterol) in the blood. There are two types. High-density lipoprotein (HDL) and low density lipoproteins (LDL). They can be taken up by cells once released in the blood.

Question 8

What are High-density lipoproteins?

Answer 8

They are produced by the combination of unsaturated fats, cholesterol and proteins. They carry cholesterol from the body back to the liver. the liver cells have receptor sites to allow HDL’s to bind to their surface membrane. Here in the liver, the HDL’s are broken down or turned to bile so High HDL’s are associated with low cholesterol.

Question 9

What are low-density lipoproteins?

Answer 9

Made up of saturated fats, cholesterol and proteins. They carry cholesterol from the liver to tissues which have receptors to allow LDL’s to bind t their surface. High amounts of these will cause deposition on artery walls.

Question 10

How can we make food production (with plants) more efficient?

Answer 10

• Improve growth rate of crops
• Increase yield size for each plant
• Reduce crop loss due to pests and disease
• Standardise size to make harvesting easier
• Improve plant responses to fertilisers

Question 11

How an we make food production (with animals) more efficient?

Answer 11

• Improve rate of growth
• Improve productivity
• Improve resistance to disease

Question 12

Explain selective breeding

Answer 12

Charles Darwin described it as the intentional breeding of certain traits (or combination of). There are three stages : 1. isolation 2. artificial selection 3. inbreeding or line breeding. In practice, a pair of animas are selected who have desirable traits, and they are bred together. the offspring are searched so that only those with the desirable characteristics are allowed to breed. this can continue for many generations.

Question 13

How are fretilisers used to increase food production?

Answer 13

Replace minerals in the soil that have been removed by previous crops (mostly potassium, nitrates and phosphate) to increase size of crops.

Question 14

How are pesticides and fungicides used to increase food production.

Answer 14

Pesticides kill organisms that cause disease to the crop that would otherwise kill ore reduce the yield of the crop. Fungicides reduce the effect of fungal growth in eaves or roots. (animals can also be treated with pesticides - sheep are treated to reduce ticks)

Question 15

How are antibiotics used to increase food production.

Answer 15

Infected animals can be treated with antibiotics, as diseases can spread easily where animals are intensely farmed close to one another. This can effect growth and reproductivity.

Question 16

What are the four ways that microorganisms can spoil food?

Answer 16

• Visible growth on food, mostly when fungi grow on food. E.g. the mould penicillium grows o bread
• External digestion processes, releasing enzymes and absorbing nutrients. food often smells sweet as carbs release sugars.
• Toxins can be produced by a microorganism. (bacteria clostridium botulinum produce botulin and is VERY toxic.
• Can cause infections (e.g. Salmonella bacteria attacks stomach linings)