Human Nutrition

Question 1

What are carbohydrates made from (including the elements)?

Answer 1

Starch/glycogen are long chains of carbohydrates which are made up of smaller chains, like glucose/maltose

Carbon, Hydrogen and Oxygen

Question 2

What are proteins made from (including the elements)?

Answer 2

Long chains of amino acids

Carbon, Hydrogen, Oxygen and Nitrogen (CHON)

Question 3

What are lipids made from (including the elements)?

Answer 3

Built from fatty acids and glycerol

Carbon, Hydrogen and Oxygen

Question 4

What is the test for Glucose?

Answer 4

Benedict’s Test

This is the hot tub one

Question 5

What is the colour change for a Benedict’s Test?

Answer 5

Negative = Blue
Positive = Green to Yellow to Red (depends on conc.)

Question 6

What is the test for Starch?

Answer 6

Iodine solution

Question 7

What is the colour change for Iodine solution?

Answer 7

Negative = Orange
Positive = Blue/black

Question 8

What is the test for Protein?

Answer 8

Biuret’s test

Question 9

What is the colour change for Biuret’s Test?

Answer 9

Negative = Blue
Positive = Pink/Purple

Question 10

What is the test for Lipids?

Answer 10

Sudan III stain Test

Question 11

What is the colour change for Sudan III test?

Answer 11

Negative: Mixture will remain colourless
Positive: Mixture will separate into two layers; top layer will be red

Question 12

What do carbohydrates do in the body?

Answer 12

Provide energy

Question 13

What do lipids do in the body?

Answer 13

Provide energy
Act as an energy store
Provide insulation

Question 14

What do proteins do in the body?

Answer 14

Needed for growth and repair of tissue
Provides energy (in emergencies)

Question 15

What foods contain Vitamin A?

Answer 15

Liver

Question 16

What does Vitamin A do in the body?

Answer 16

Helps improve vision
Keeps skin/hair healthy

Question 17

What does Vitamin C do in the body?

Answer 17

Needed to prevent scurvy

Question 18

What foods contain Vitamin C?

Answer 18

Citrus fruits

Question 19

What does Vitamin D do in the body?

Answer 19

Needed for calcium absorption

Question 20

What foods contain Vitamin D?

Answer 20

Eggs

Also made by body when skin exposed to sunlight

Question 21

What does calcium do in the body?

Answer 21

Needed to make bones and teeth

Question 22

What does iron do in the body?

Answer 22

Needed to make haemoglobin for healthy blood

Question 23

Why is water needed in the body?

Answer 23

Nearly every bodily function relies on water.

Need to constantly replace water we lose through urinating/breathing/sweating

Question 24

What does fibre do in the body?

Answer 24

Aids the movement of food through the gut

Question 25

What is a balanced diet?

Answer 25

Gives all of the essential nutrients you need in the *right proportions*

Question 26

Why do pregnant women need more energy than other women?

Answer 26

They have to provide energy for both them and their babies development

Question 27

Describe an experiment to measure how much energy is in food.

Answer 27

1. Weigh a food that will burn easily (preferably dry food) 2. Add a set volume of water to a tube and measure its temperature 3. Set fire to the food sample with a Bunsen burner and immediately hold under the water 4. Repeat until the food won't relight again, then measure the temperature change of the water

Question 28

What is the formula to calculate the amount of energy in Joules

Answer 28

Energy in food (J) = Mass of water * Temperature change * 4.2

Question 29

What is the 4.2 in the formula for?

Answer 29

The amount of energy (in joules) needed to raise 1g of water by 1C

Question 30

What is the formula to calculate the amount of energy in Joules/Gram

Answer 30

Energy/g of food (J/g) = Energy in food (J) / Mass of food (g)

Question 31

How can we make this experiment more accurate?

Answer 31

Insulate the boiling tube with foil (minimise heat loss)

Question 32

What enzymes break starch into maltose?

Answer 32

Starch + **Amylase** -> Maltose

Question 33

What enzymes break maltose into glucose?

Answer 33

Maltose + **Maltase** -> Glucose

Question 34

What enzymes convert proteins into amino acids?

Answer 34

Protein + **Protease** -> Amino acids

Question 35

What enzymes convert lipids into glycerol and fatty acids>

Answer 35

Lipids + **Lipase** -> Glycerol + Fatty acid

Question 36

How is bile useful?

Answer 36

Neutralises the stomach acid Emulsifies fats

Question 37

What is emulsification?

Answer 37

The break down of fat into tiny droplets, giving a bigger SA

Question 38

How does food move through the gut?

Answer 38

Peristalsis Squeezes balls of food (boluses) through the gut

Question 39

What does the mouth do?

Answer 39

Teeth break down the food (Mechanical digestion) Secretes amylase in the saliva (Chemical digestion)

Question 40

What does the oesophagus do?

Answer 40

Muscular tube connecting the mouth and the stomach

Question 41

What does the stomach do?

Answer 41

Pummels the food with its muscular walls Produces protease enzyme *pepsin* Produces HCl to kill bacteria and provide optimum pH for protease

Question 42

What does the liver do?

Answer 42

Where bile is produced

Question 43

What does the gall bladder do?

Answer 43

Where bile is stored

Question 44

What does the pancreas do?

Answer 44

Produces protease, amylase and lipase. Releases these into the small intestine

Question 45

What does the large intestine (colon) do?

Answer 45

Excess water is absorbed from the food

Question 46

What does the small intestine do?

Answer 46

Produces amylase, lipase and protease Where nutrients are absorbed out of the alimentary canal First part = duodenum; last part = Ileum

Question 47

How are villi adapted to help with absorption?

Answer 47

Massive surface area -> walls of SA covered in villi, which are all covered with microvilli Single permeable layer of surface cells Good blood supply