food substances

Question 1

Name the 3 primary food substances and the 3 protective food substances.

Answer 1

Primary: carbohydrates, lipids, proteins
Protective: vitamins, minerals, dietary fibers

Question 2

Name 3 examples of disaccharides.

Answer 2

Maltose (glucose+glucose)
Sucrose (glucose+fructose)
Lactose (glucose+galactose)

Question 3

Name 3 examples of polysaccharides.

Answer 3

Starch (stored in plants)
Glycogen (stored in animals)
Cellulose (plant cell walls)

Question 4

What are the uses of lipids?

Answer 4

。energy storage 38.9 kJ (carbohydrates -> lipids -> proteins)
。heat insulator
。shock insulator
。major component of cell membranes

Question 5

Name 3 examples of monosaccharides.

Answer 5

Glucose
Fructose
Galactose

Question 6

Triglyceride molecules are made out of?

Answer 6

1 glycerol molecule and 3 fatty acids

Question 7

Lipids are …….. in water, but can be dissolved in …………

Answer 7

insoluble; organic solvents

Question 8

What are the uses of proteins?

Answer 8

。energy storage 18.2 kJ (carbohydrates -> lipids -> proteins)
。help with growth
。enzymes, hormones etc.

Question 9

What are proteins made out of?

Answer 9

more than 1 polypeptide (chains of amino acids)

Question 10

What are the uses of carbohydrates?

Answer 10

。main energy source 17.1 kJ (carbohydrates -> lipids -> proteins)
。energy reserve: excess converted into glycogen or lipids
。structural material: cellulose for making cell walls
。major source of dietary fibre

Question 11

Name 3 kind of molecules of lipids.

Answer 11

Triglyceride, phospholipids, cholesterol

Question 12

What is a dipeptide?

Answer 12

2 amino acids linked by peptide bonds

Question 13

What is a polypeptide?

Answer 13

more than 2 amino acids linked by peptide bonds

Question 14

What happens to the excess amino acids?

Answer 14

Liver breaks down excess amino acids by deamination and are converted into urea

Question 15

What are minerals?

Answer 15

。no energy value
。regulate metabolism
。forming body tissues

Question 16

Name 3 examples of minerals.

Answer 16

Calcium, iron, iodine

Question 17

What are the functions and deficiency disease of calcium?

Answer 17

Functions:
。form teeth and bones
。form blood clots
Deficiency disease:
。rickets (kids): bones turn soft and bends outwards
。osteoporosis (adults): bone becomes brittle

Question 18

What are the functions and deficiency diseases of iron?

Answer 18

Functions:
。synthesize haemoglobin
Deficiency disease:
。anaemia: lack of haemoglobin -> faint easily

Question 19

What are the functions and deficiency diseases of iodine?

Answer 19

Functions:
。maintain function of thyroid gland
Deficiency diseases:
。goitre: thyroid gland becomes swollen

Question 20

What are vitamins?

Answer 20

。no energy value
。essential for maintaining normal functions of cells and organs
。regulate metabolism
。strengthen immunity

Question 21

Name 3 examples of vitamins.

Answer 21

Vitamin A, vitamin C, vitamin D

Question 22

What are the functions and deficiency diseases of vitamin A?

Answer 22

Functions:
。forms visual purple in rod cells in retina -> for night vision
。protect cornea
。strengthen immunity
Deficiency disease:
。night blindness

Question 23

What are the functions and deficiency diseases of vitamin C?

Answer 23

Functions:
。synthesize + repair tissues for healing wounds
。strengthen immunity
Deficiency disease:
。scurvy

Question 24

What are the functions and deficiency diseases of vitamin D?

Answer 24

Functions:
。promotes absorption of calcium and phosphate ions -> strong bones + teeth
Deficiency diseases:
。rickets (kids)
。osteoporosis (adults)

Question 25

What are the functions and deficiency diseases of dietary fibres?

Answer 25

Functions:
。promote peristalsis
。soften faeces
。facilitate egestion
Deficiency diseases:
。constipation

Question 26

What are the functions of water?

Answer 26

。main component of cytoplasm and blood
。medium for chemical reactions
。solvent for wastes
。make body secretions
。regulate body temperature (evaporation of sweat)