Nutrition and Health (3)

Question 1

The seven main nutrients in food are:

Answer 1

• fat
• carbohydrates
• fibre
• protein
• water
• vitamins (C&D)
• minerals

Question 2

The elements present in the main food groups are:

Answer 2

Carbs, fibre & fat = carbon, hydrogen, and oxygen

Protein = carbon, hydrogen, oxygen and nitrogen

Question 3

What is a balanced diet?

Answer 3

All of the essential food groups in the correct proportion

Question 4

What is an unbalanced diet?

Answer 4

This is a diet which contains too much of some of the essential nutrients and/or too little of others. This type of diet can lead to the body being damaged

Question 5

What is a food test?

Answer 5

Food tests are carried out to identify what substances are present in foods. The food has to be put in a solution I.e. Dissolved in water, and then it can be tested for different food groups

Question 6

Equipment needed for food tests

Answer 6

Safety goggles, 
wire gauze, 
heat proof mat,
Bunsen burner,
Tripod,
Spatula,
Pipette,
Test tube rack,
Boiling tubes,
Beaker,
Spotting tile,
Pestle,
Mortar 
And food samples

Question 7

Describe the test for starch

Answer 7

Name of test - starch test
Method - add iodine solution (yellow-brown) to the food.
Positive result- it will turn from yellow/brown to blue/black

Question 8

Describe the test for sugar

Answer 8

Name of test- Benedict’s test
Method - add Benedict’s solution (blue) to the food and heat in a water bath
Positive result - from blue to purple (lilac)

Question 9

Describe the test for protein/amino acid

Answer 9

Name of test - Biuret test
Method - add sodium hydroxide to the food and then copper sulphate and shake
Positive result - it will turn from blue to green then orange then to a brick red precipitate depending on how much sugar is present

Question 10

Describe the test for fat

Answer 10

Name of test - ethanol test
Method - mix the food with ethanol
Positive result - from clear to form a white emulsion

Question 11

Describe the test for vitamin C

Answer 11

Name of test - DCPIP test
Method - add DCPIP (blue) to the food
Positive result - from blue to pink and then colourless

Question 12

Explain the DCPIP test

Answer 12

Vitamin C or ascorbic acid, is a powerful reducing agent and a dye called DCPIP can be used to detect it. The vitamin C causes the dark blue colour to be decolourised to pink and eventually going colourless

Question 13

Apparatus for the DCPIP test

Answer 13

Beaker,
Syringe,
DCPIP solution,
Standard solution of ascorbic acid,
Test tubes,
Test tube rack,
And fruit juice samples.

Question 14

Examples of how are body uses energy and where it’s from

Answer 14

Your body uses energy all the time. We need energy for our heat to pump blood around the body, our brain to think and learn and our muscles to move. We get energy from the food we eat.

Question 15

What are kilojoules and examples of them

Answer 15

Kilojoules are a measurement of energy.
1000 joules = 1 kilojoule (KJ) 
-1g of protein provides us with 17KJ 
- 1g of fat provides us with 38KJ 
- 1g of carbs provides us with 17KJ

Question 16

How much energy do we need?

Answer 16

Approximately 70% of the energy you use up everyday keeps the body working. The other 30% is used for extra work and activities. The amount of energy that you need will vary at different times of your life.

Question 17

Energy requirements of our body depend on three main factors:

Answer 17

Age - a teenager who is growing will require more energy than an elderly person
Gender - (male or female) generally men require more energy as they usually have more muscles and a larger body mass
Activity levels - an active person who does a lot of exercise will require more energy than someone sitting watching tv

Question 18

What does BMI stand for

Answer 18

Body mass index

Question 19

What is BMI & what is it used for

Answer 19

BMI is often used by health professionals to check if a patient is the right weight for their height

BMI = weight in kgs - divided by - (height in m)squared

Question 20

What does BMR stand for & what is it?

Answer 20

Basal metabolic rate.
BMR is a measure of minimum- energy expenditure - how much energy is required to keep your body functioning when you are resting and relaxing in a (also known as your metabolism). It must be carried out long enough after a meal for digestion to be complete.

Question 21

What will increase your BMR?

Answer 21

Anything that results in an increase to your metabolic rate. This includes exercise, stress, fear and illness

Question 22

What is your BMR relative to?

Answer 22

Your body mass, age, weight and height. It is also affected by your gender; as it is widely regarded that men need more energy than women.

Question 23

State three body functions that we need energy for as part of our BMR

Answer 23

• Breathing
• beating of the heart
• metabolism of cells

Question 24

Suggest why our BMR tends to decrease as we get older

Answer 24

Less growth ie less metabolic activity

Question 25

Explain the Harris Benedict equation

Answer 25

Once you have calculated your BMR, it is then put into the Harris Benedict equation, which calculates your total calorie intake required to maintain your current weight i.e. Not gaining or losing any weight. This is calculated by multiplying your BMR by a particular activity factor.

Question 26

Our diet has a major effect on our health. There are a number of features of our diet that contribute to many people not being as healthy as they could be:

Answer 26

1 the genes we have inherited from our parents could influence our health. For example, our cholesterol levels and the likelihood of suffering from heart disease are dependant on our genetics, as well as our diet

2 obesity (being very overweight) can be caused by a person taking in too much energy (sugar, starch or fat). Their energy intake is higher than the energy they use in exercise. The extra energy is stored in the body as fat.

3 we often do not make healthy food choices. We may eat too many foods which are rich in salt, sugar and fat or may not eat enough food providing us with vital ingredients e.g. Fruit and vegetables. It is important to eat 5 portions of fruit and veg in order to get enough vitamins and minerals

As well as obesity, poor diets contribute to many other health problems

Question 27

Explain heart disease

Answer 27

Heart disease (heart attack, heart failure, sudden cardiac death, chest pain etc) is caused by high levels of cholesterol and other fatty substances. These substances build up in the walls of the arteries, causing them to become narrow. This makes it more difficult for blood to flow through them and may result in a heart attack.

Question 28

Explain a stroke

Answer 28

A poor diet can damage the circulatory system in other parts of the body as well as the heart. If the cholesterol and fatty substances build up so much that they block an artery in the brain, a stroke can result.

Question 29

Explain high blood pressure

Answer 29

The extra weight carried by an obese person can result in high blood pressure. The heart has to work harder to pump blood around the extra tissues in the body. This greater wear and tear of the heart can damage it or blood vessels. The narrowing of arteries (caused by the build up of fatty deposits) can also result in high blood pressure as it can make it harder to pump blood. Too much salt in the diet can also contribute to high blood pressure

Question 30

Explain diabetes

Answer 30

A poorly balanced diet or obesity can lead to type 2 diabetes. This is when the body experiences sugar ‘overload’ and the hormone insulin no longer is effective in controlling sugar levels in the body.

Question 31

Explain arthritis

Answer 31

A person who is very overweight may suffer from arthritis. This is when the joints, particularly in the knees, hips and lower back, become damaged due to wear and tear they experience owing to the extra weight the person is carrying

Question 32

Explain obesity and the cost to society

Answer 32

Currently over 20% of the U.K. are obese and this percentage is rapidly rising, having doubled over the last 20 years. The rising number of obese people significantly adds to the costs of the national health service (NHS) .

Direct costs are estimated to be £4.2 million and it is forecasted that this will more than double by 2050 if we continue as we are. As well as treating people for obesity itself, there are medical costs of treating the conditions associated with obesity e.g. Heart disease, type 2 diabetes

Question 33

Humans need to take in food to survive. The main functions of food are:

Answer 33

1 energy - food is needed to provide energy to carry out the activities and reactions of the body

2 growth and repair - as you grow you make new cells. You also need to replace old damaged cells. New cells are made from chemicals I’m food

3 protection - chemicals in food are needed for the activities required to keep you healthy and protect you against disease