Human Nutrition

Question 1

Describe what is meant by a balanced diet

Answer 1

A diet containing proper proportions of
carbohydrates, fats, proteins, vitamins, minerals and water to maintain good health and metabolism

Question 2

Describe the importance of carbohydrates

Answer 2

Energy

Question 3

Describe the importance of fats and oils

Answer 3

Source of energy, building materials, energy store, insulation, buoyancy, making hormones

Question 4

Describe the importance of proteins

Answer 4

Energy, building materials, enzymes, haemoglobin, structural material (muscle), hormones, antibodies

Question 5

Describe the importance of vitamins C and D

Answer 5

Vitamin C: Collagen, resistance to diseases
Vitamin: D Absorption of calcium

Question 6

Describe the importance of calcium and iron

Answer 6

Calcium: Development and maintenance of
strong bones and teeth
Iron: Making haemoglobin

Question 6

Describe the importance of fibre

Answer 6

Provides bulk for faeces, helps peristalsis

Question 7

Describe the importance of water

Answer 7

Chemical reactions, solvent for
transport

Question 8

State the causes of scurvy and rickets

Answer 8

Vitamin C: Scurvy; loss of teeth, pale skin &
sunken eyes
Calcium/Vitamin D: Rickets, Osteoporosis;
weak bones and teeth

Question 9

What is ingestion

Answer 9

taking substances (e.g. food, drink) into the
body through the mouth.

Question 10

What is physical digestion

Answer 10

breakdown of food into smaller pieces
without chemical change.

It increases the surface area of food for the action of enzymes in chemical digestion

Question 11

What is chemical digestion

Answer 11

Breakdown of large, insoluble food
molecules into small, soluble molecules.

Question 12

What is absorption

Answer 12

The movement of nutrients from the intestines into the blood

Question 13

What is assimilation

Answer 13

uptake and use of nutrients by cells

Question 14

What is egestion

Answer 14

the removal of undigested food from the body as faeces

Question 15

Function of the mouth in the alimentary canal

Answer 15

contains teeth used for mechanical digestion, an area where food is mixed with salivary amylase & where ingestion takes place

Question 16

Function of the salivary glands in the alimentary canal

Answer 16

produce saliva, which contains amylase
and helps food slide down oesophagus

Question 17

Function of the oesophagus in the alimentary canal

Answer 17

tube-shaped organ which uses peristalsis
(circular muscle contract and relax) to transport food from mouth to stomach

Question 18

Function of the stomach in the alimentary canal

Answer 18

has pepsin (a protease) to break down proteins into amino acids and kills bacteria with hydrochloric acid. They also have elastic walls

Question 19

Function of the duodenum in the alimentary canal

Answer 19

fats are emulsified by bile and digested by
pancreatic lipase to form fatty acids and glycerol.
Pancreatic amylase and trypsin (a protease) break down starch.

Question 20

Function of the Ileum in the alimentary canal

Answer 20

Maltase breaks down maltose to glucose. This is where absorption takes place, adapted by having villi and microvilli

Question 21

Function of the pancreas in the alimentary canal

Answer 21

produces amylase, trypsin and lipase

Question 22

Function of the gal bladder in the alimentary canal

Answer 22

stores bile from the liver

Question 23

Function of the liver in the alimentary canal

Answer 23

produces bile (emulsifies fats, neutralises acidic fat molecules), deamination and makes urea to be sent to the kidney. Also, site of the breakdown of alcohol and other
toxins.

Question 24

Function of the colon in the alimentary canal

Answer 24

organ for absorption of minerals and vitamins and reabsorbing water from waste to maintain the body’s water levels

Question 25

Function of the rectum in the alimentary canal

Answer 25

where faeces are temporarily stored

Question 26

Function of the anus in the alimentary canal

Answer 26

a ring of muscle which controls when faeces is released

Question 27

Describe the structure of a tooth

Answer 27

Enamel: the strongest tissue in the body made from calcium salts Cement: helps to anchor tooth Pulp: contains tooth-producing cells, blood vessels, and nerve endings which detect pain. Dentine: calcium salts deposited on a framework of collagen fibres Nerves Blood vessels

Question 28

What is the function of amylase

Answer 28

breaks down starch into maltose; it is produced in the pancreas (but also in the salivary gland)

Question 29

What is the function of maltase

Answer 29

breaks down into glucose in the membrane of the epithelium lining in small intestines.

Question 30

What is the function of protease

Answer 30

breaks down proteins into peptides (done by pepsin-acidic) and then into amino acids (done by trypsin). Pepsin comes from the stomach and trypsin from the pancreas (alkali)

Question 31

What is the function of lipase

Answer 31

breaks down lipids into fatty acids and glycerol, produced by the pancreas.

Question 32

What is the function of hydrochloric acid in gastric juice

Answer 32

Denaturing enzymes in harmful microorganisms Giving the optimum pH for pepsin activity Kills pathogens

Question 33

What is the function of bile

Answer 33

an alkaline mixture that neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach to provide a suitable pH for enzyme action.

Question 34

Function of lacteals

Answer 34

absorbs fatty acid and glycerol

Question 35

Function of capillaries

Answer 35

provide a better blood supply