Nutrition in humans

Question 1

The mouth, stomach and duodenum all use what to break down food?

Answer 1

Enzymes

Question 2

What happens in the ileum?

Answer 2

Digested food is absorbed

Question 3

What happens in the colon?

Answer 3

Remaining water is absorbed

Question 4

Where is faeces stored?

Answer 4

The rectum

Question 5

What is peristalsis?

Answer 5

Behind the food circular muscles contract and radial muscles relax, squeezing the gut. Around the food radial muscles contract and circular muscles relax, expanding the gut

Question 6

Sources of carbohydrates?

Answer 6

Starch in plants (potatoes, rice, wheat and millet), sugars in fruit and veg (sucrose and fructose) and processed food/drink (coca-cola, sweets and biscuits)

Question 7

Function of carbohydrates?

Answer 7

Source of energy

Question 8

Sources of proteins?

Answer 8

Meats, fish, cheese, eggs, beans, peas and nuts

Question 9

Functions of proteins?

Answer 9

• Growth and repair
• Helps to form enzymes

Question 10

Sources of lipids?

Answer 10

Meat, butter, cheese, milk, eggs, oily fish, olive oil, corn oil, rapeseed oil and margarine

Question 11

Functions of lipids?

Answer 11

• Essential to form cell membrane
• Used for long-term energy store
• Thermal insulation
• Protection from mechanical damage

Question 12

Sources of vitamin A?

Answer 12

Fish liver oils, livers, butter, margarine and carrots

Question 13

Function of vitamin A?

Answer 13

Makes light-sensitive chemicals in retina

Question 14

Sources of vitamin C?

Answer 14

Fresh fruit and veg

Question 15

Functions of vitamin C?

Answer 15

Makes fibres of connective tissues in blood vessels and skin; Helps stick cells together

Question 16

Sources of vitamin D?

Answer 16

Fish liver oils and sunlight

Question 17

Function of vitamin D?

Answer 17

Helps bones grow by taking up calcium salts and phosphates

Question 18

Sources of calcium?

Answer 18

Dairy products, fish, bread and veg

Question 19

Function of calcium?

Answer 19

Makes teeth and bones

Question 20

Sources of iron?

Answer 20

Red meat, liver, eggs and spinach

Question 21

Function of iron?

Answer 21

Makes haemoglobin

Question 22

Sources of fibre?

Answer 22

Fruit, veg and wholegrain plant matter

Question 23

Function of fibre?

Answer 23

Provides something for the gut muscles to push against

Question 24

Sources of water?

Answer 24

Water

Question 25

Functions of water?

Answer 25

- A solvent for chemical reactions - Transfers heat efficiently

Question 26

Digestive action of amylase?

Answer 26

Starch to maltose

Question 27

Digestive action of maltase?

Answer 27

Maltose to glucose

Question 28

Sources of amylase?

Answer 28

Salivary glands and pancreas

Question 29

Source of maltase?

Answer 29

Wall of small intestine

Question 30

Where amylase acts?

Answer 30

Mouth and small intestine

Question 31

Digestive action of pepsin?

Answer 31

Proteins to peptides

Question 32

Digestive action of trypsin?

Answer 32

Proteins to peptides

Question 33

Digestive action of peptidase?

Answer 33

Peptides to amino acids

Question 34

Source of pepsin?

Answer 34

Stomach wall

Question 35

Source of trypsin?

Answer 35

Pancreas

Question 36

Source of peptidase?

Answer 36

Wall of small intestine

Question 37

Where pepsin acts?

Answer 37

Stomach

Question 38

Where trypsin acts?

Answer 38

Small intestine

Question 39

Where peptidase acts?

Answer 39

Small intestine

Question 40

Digestive action of lipase?

Answer 40

Lipids to glycerol and fatty acids

Question 41

Source of lipase?

Answer 41

Pancreas

Question 42

Where lipase acts?

Answer 42

Small intestine

Question 43

Where is bile produced?

Answer 43

Liver

Question 44

Where is bile stored?

Answer 44

Gall bladder

Question 45

What does bile do?

Answer 45

Neutralises stomach acid and emulsified lipids

Question 46

Why does the ileum have a large surface area?

Answer 46

To maximise absorption

Question 47

What do epithelium cells contain?

Answer 47

Contain many mitochondria for active transport and have many microvilli to further increase surface area

Question 48

What do capillaries do?

Answer 48

Absorb nutrients into blood stream

Question 49

What does lacteal do?

Answer 49

Absorbs fat products and tiny fat droplets into the lymphatic system

Question 50

Why does each villi contain a muscle fibre?

Answer 50

To constantly move it so it remains in contact with the contents of the ileum and maintains a steep concentration gradient

Question 51

Describe an experiment to measure the energy content of a food?

Answer 51

1. Weigh the food sample 2. Measure 20cm cubed of water into a boiling tube and clamp it with a thermometer inside and record the temperature 3. Spear the sample on the end of a mounted needle and light it 4. Hold the burning food underneath the boiling tube, relighting it if it goes out, until the food will no longer burn 5. The final temperature of the water is measured 6. Energy in J per g = (final temp - initial temp)x20x4.2/mass of sample