Human Nutrion

Question 1

What type of biological molecules are made up of amino acids

Answer 1

Proteins

Question 2

Describe how you could use Benedicts reagent to test for glucose

Answer 2

You can add Benedicts reagent (which starts off blue) to sample and heat it making sure the solution doesn’t boil
If the test is positive it will form a coloured precipitate, it goes from blue-green-yellow-orange-brick red

Question 3

What test could you do to see if starch is present

Answer 3

Add iodine solution to the test sample
If starch is present,the same changes from browny-orange to blue-black
If there’s no starch it remains browny-orange

Question 4

Why does the body need proteins, give examples of where proteins are found

Answer 4

Proteins are needed for growth and relate of tissue and to provide energy in emergencies
They are found fish and meat

Question 5

State the two nutrients that your body gets energy from

Answer 5

Carbohydrates (pasta, rice, sugar)

Lipids (oily fish, butter)

Question 6

Why doe we need vitamin D and how can we obtain it

Answer 6

It is needed for calcium absorption

Can be obtained from eggs

Question 7

Explain what is meant by a balanced diet

Answer 7

A balanced diet gives you all the essential nutrients you need in the right proportions
The six essential nutrients are carbohydrates, lipids, vitamins, minerals, water and proteins
You also need fibre to keep the gut working

Question 8

Explain how energy requires vary in different people

Answer 8

The amount of energy each person needs is different. There are 3 things it depends on:
ACTIVITY LEVEL: Active people need more energy than people who sit around all day
AGE:children and teenagers need more energy than older people. They need energy to grow
PREGNANCY: pregnant women need more energy than other women as they’ve got to provide the energy their babies need to develop

Question 9

Describe the experiment in which you can measure the amount of energy in food

Answer 9

Food can be burnt to see how much energy it contains
1) weigh a small amount of dry food (peanuts/crisps) and put it on a needle
2) add 25cm3 to a boiling tube held with a clamp
3) measure the temperature of the water and using a Bunsen burner set fire to the food
4) hold the burning food under the boiling tube until it goes out
5) continue to relight the food and burn it until it will no longer relight
Then measure the temperature of the water

Question 10

How do you calculate he amount of energy in food

Answer 10

CALCULATE THE AMOUNT OF ENERGY IN JOULES:
Energy in food= mass of water x temperature change of water x 4.2
CALCULATE THE AMOUNT OF ENERGY IN JOULES PER GRAM:
Energy per gram in good = energy in food (J) \ mass of food (g)

Question 11

What is the main role of digestive enzymes

Answer 11

Digestive enzymes break down big molecules into smaller one

Question 12

Name the enzymes that convert starch into glucose

Answer 12

Carbohydrase/amalayse

Question 13

What do proteases do

Answer 13

Proteases convert proteins into amino acids

Question 14

What molecules are lipids broken down into

Answer 14

Lipases convert lipids into glycerol and fatty acids

Question 15

Where in the body is bile:

1) produced
2) stored
3) used

Answer 15

1) liver
2) gall bladder
3) small intestine to neutralise stomach acid and emulsify fat

Question 16

Describe the chorion of the mouth

Answer 16

1) salivary glands in the mouth produce analyse enzyme in the saliva
2) teeth break down food mechanically

Question 17

Describe the function of the oesophagus

Answer 17

It is the muscular tube that connects the mouth and stomach

Question 18

Describe the function of the stomach

Answer 18

1) it pummels food with its muscular walls
2) it produces protease enzyme, pepsin
3) it produces hydrochloric acid to kill bacteria and give the right pH for the protease enzyme to work (pH 2 acidic)

Question 19

Describe the function of the pancreas

Answer 19

Produces protease, amalayse and lipase enzymes. It releases these junto the small intestine

Question 20

Describe the function of the small intestine

Answer 20

Produces protease, analyse and lipase enzymes to complete digestion
This is also where the nutrients are absorbed out of the alimentary canal into the body

Question 21

Describe the process of peristalsis

Answer 21

1) there’s a muscular tissue all the way down the alimentary canal
2) it’s job is to squeeze balls of food through your gut otherwise it will get clogged up
3) the squeezing action which is waves of circular muscles of contractions is called peristalsis

Question 22

Explain how villi help with the absorption in the small intestine

Answer 22

The millions and millions of tiny villi create a large surface area enabling maximum absorption. Each villi even has a micro villi which enable even more absorption. Villi have a single permeable layer of surface cells and a very good blood supply to assist quick absorption

Question 23

What type of biological molecules are made up of fatty acids and glycerol

Answer 23

Lipids