Section 2: Human Nutrition

Question 1

what are carbohydrates made up of?

Answer 1

simple sugars

Question 2

what elements do carbohydrate molecules contain?

Answer 2

carbon, hydrogen and oxygen

Question 3

what are starch and glycogen (two examples of large, complex carbohydrates) made up of?

Answer 3

starch - maltose, glycogen- glucose

Question 4

what are proteins made up of?

Answer 4

amino acids

Question 5

what elements do proteins contain?

Answer 5

carbon, nitrogen, hydrogen and oxygen

Question 6

what are lipids made up of?

Answer 6

fatty acids and glycerol

Question 7

what elements do lipids contain?

Answer 7

carbon, hydrogen and oxygen

Question 8

what is the test for glucose? what colour change of precipitates can be observed?

Answer 8

benedict’s reagent: precipitate turns from blue-green-yellow-orange-brick red in the presence of glucose

Question 9

what is the test for starch?

Answer 9

iodine turns from browny orange to dark bluish black in the presence of starch.

Question 10

what is the function of carbohydrates?

Answer 10

they provide energy

Question 11

what are the functions of lipids?

Answer 11

provide energy, act as an energy store, provide insulation

Question 12

what is the function of proteins?

Answer 12

needed for the growth and repair of tissue, provide energy in emergencies

Question 13

what is the function of Vitamin A?

Answer 13

helps tp improve vision , keeps skin and hair healthy

Question 14

what is the function of Vitamin C?

Answer 14

prevents scurvy

Question 15

what is the function of Vitamin D?

Answer 15

needed for calcium absorption

Question 16

what is the function of Calcium? what kind of nutrient is it?

Answer 16

it is a mineral ion, needed to make bones and teeth

Question 17

what is the function of the mineral ion iron?

Answer 17

needed to make haemoglobin for healthy blood

Question 18

what is the function of water in the body?

Answer 18

constant supply is needed to replace water lodt through urination, breathing, sweating etc… almost every bodily function relies on water

Question 19

what is the function of dietary fibre?

Answer 19

aids movement of food through the gut

Question 20

What are the six essential nutrients

Answer 20

Carbohydrates, proteins, lipids, vitamins minerals and water

Question 21

Describe the process of calorimetry

Answer 21

Weigh a small amount of food, skewer on a mounted needle. Add water to a boiling tube and measure the temperature of it. Set fire to the food using a Bunsen burner flame. Hold the burning food under the boiling tube until it goes out, relight it until the food won’t catch fire again. Measure the temperature change

Question 22

How to calculate the amount of energy in food (joules)

Answer 22

Energy in food = mass of water(g) x temperature change of water(•C) x 4.2

Question 23

How to calculate the amount of energy in joules per gram?

Answer 23

Energy per gram of food = energy in food(J) / mass of food(g)

Question 24

What does amylase do?

Answer 24

Converts starch into maltose

Question 25

What does maltase do?

Answer 25

Converts maltose into glucose

Question 26

What digestive enzyme breaks proteins down into amino acids?

Answer 26

Protease

Question 27

What does lipase break lipids into?

Answer 27

Glycerol and fatty acids

Question 28

What are the four digestive enzymes?

Answer 28

Amylase, lipase, protease, maltase

Question 29

what is the role of bile in the digestive process?

Answer 29

neutralises the stomach acid and emulsifies fats

Question 30

where is bile produced and stored and released?

Answer 30

produced in the liver, stored in the gall bladder, released into the small intestine

Question 31

how does bile emulsify fats?

Answer 31

it breaks fats into tiny droplets so that there is a larger surface area of fat for the lipase enzyme to work on

Question 32

what is the pH of bile? why?

Answer 32

it is alkaline, to neutralise the acidic