Human Nutrition

Question 1

Structure of carbohydrates

Answer 1

Long chains of simple sugars
Contain carbon, hydrogen, oxygen

Question 2

Structure of proteins

Answer 2

Long chains of amino acids
When amino acids join together, they form peptide bonds, forming proteins
Contain carbon, hydrogen, oxygen, nitrogen

Question 3

Structure of lipids

Answer 3

3 fatty acids and 1 glycerol
(Forming a triglyceride)
Contain carbon, hydrogen and oxygen

Question 4

Food test for glucose

Answer 4

Benedict’s solution - use a water bath (75 degrees)
Brick red/orange/green

Question 5

Food test for starch

Answer 5

Add iodine
Blue/black if present

Question 6

Food test for protein

Answer 6

Buiret reagent
Purple if present

Question 7

Food test for lipids

Answer 7

Add ethanol
White emulsion forms if present

Question 8

Carbohydrates function

Answer 8

Short term energy

Question 9

Lipids function

Answer 9

Long term energy, insulation and protection

Question 10

Protein function

Answer 10

Growth and repair

Question 11

Calcium function and deficiency

Answer 11

Strong bones and teeth
Osteoporosis

Question 12

Iron function and deficiency

Answer 12

Carry’s oxygen
Anemia

Question 13

Fibre function and deficiency

Answer 13

Helps aid digestion
Constipation

Question 14

Water function

Answer 14

A medium in which chemical reactions occur

Question 15

Vitamin A function and deficiency

Answer 15

Improve vision (eyes)
Night blindness

Question 16

Vitamin C function and deficiency

Answer 16

Gums and teeth
Scurvy

Question 17

Vitamin D function and deficiency

Answer 17

Absorbing calcium
Rickets

Question 18

What impacts a persons energy requirements

Answer 18

Age - younger need more energy to grow
Activity level - more active people need more energy
Pregnancy - need to provide babies energy to develop

Question 19

Enzymes that break down starch

Answer 19

Amylase converts starch into maltose

Maltase converts maltose into glucose

Question 20

Enzymes that break down proteins

Answer 20

Proteases break down proteins into amino acids

Question 21

Enzymes that break down lipids

Answer 21

Lipase converts lipids into glycerol and fatty acids

Question 22

Mouth

Answer 22

Food is chewed up and swallowed
Mechanical and chemical digestion occurs
Salivary glands produce salivary amylase

Question 23

Oesophagus

Answer 23

Tube that connects the mouth to the stomach
Peristalsis (wave like contractions) push food into the stomach

Question 24

Stomach

Answer 24

Produces pepsin (protease enzyme) to break down proteins
Also has hydrochloric acid to kill bacteria and create the optimum pH for protease enzyme (acidic)

Question 25

Duodenum

Answer 25

Food comes into contact with bile

Question 26

Ileum

Answer 26

Absorption of fold molecules into the bloodstream

Question 27

Pancreas

Answer 27

Produces protease, amylase and lipase and releases them into the duodenum

Question 28

Colon

Answer 28

Water is absorbed

Question 29

Rectum

Answer 29

Stores faeces

Question 30

Anus

Answer 30

Expels faeces

Question 31

Small intestine adaptations

Answer 31

Adapted for absorption of food into bloodstream -villi - finger like projections that increase the SA for absorption -thin walls - less distance for nutrients to travel -high blood supply

Question 32

Villi

Answer 32

Finger like projections that line the small intestine -increases SA of small intestine -microvilli -good blood supply -thin permeable surface layer

Question 33

Where is bile produced and stored

Answer 33

Produced in liver Stored in gall bladder

Question 34

Role of bile

Answer 34

Emulsify lipids and neutralise stomach acid

Question 35

Energy from food practical (calorimetry) steps

Answer 35

1. Use a food that burns easily e.g. banana chip 2. Weigh a small amount of the food and then skewer it on a mounted needle 3. Add a set volume of water to a boiling tube held by a clamp 4. Measure initial temp water then set fire to food using a Bunsen burner flame 5. Immediately hold the burning food under the boiling tube until it goes out, then relight the food and repeat until food no longer catches fire 7. Measure final temp water 8. Use equation

Question 36

Equations for energy from food practical

Answer 36

Calculate the amount of energy in Joules: energy = mass x 4.2 x temp change water Then, calculate the amount of energy in joules per gram: energy = energy (J)/mass food (g)

Question 37

How to make the energy from food practical more accurate

Answer 37

Lots of energy is lost to surroundings Therefore, insulating the boiling tube (foil) would minimise heat loss and keep more energy in the water