food substances Flashcards
Name the 3 primary food substances and the 3 protective food substances.
Primary: carbohydrates, lipids, proteins
Protective: vitamins, minerals, dietary fibers
Name 3 examples of disaccharides.
Maltose (glucose+glucose)
Sucrose (glucose+fructose)
Lactose (glucose+galactose)
Name 3 examples of polysaccharides.
Starch (stored in plants)
Glycogen (stored in animals)
Cellulose (plant cell walls)
What are the uses of lipids?
。energy storage 38.9 kJ (carbohydrates -> lipids -> proteins)
。heat insulator
。shock insulator
。major component of cell membranes
Name 3 examples of monosaccharides.
Glucose
Fructose
Galactose
Triglyceride molecules are made out of?
1 glycerol molecule and 3 fatty acids
Lipids are …….. in water, but can be dissolved in …………
insoluble; organic solvents
What are the uses of proteins?
。energy storage 18.2 kJ (carbohydrates -> lipids -> proteins)
。help with growth
。enzymes, hormones etc.
What are proteins made out of?
more than 1 polypeptide (chains of amino acids)
What are the uses of carbohydrates?
。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
Name 3 kind of molecules of lipids.
Triglyceride, phospholipids, cholesterol
What is a dipeptide?
2 amino acids linked by peptide bonds
What is a polypeptide?
more than 2 amino acids linked by peptide bonds
What happens to the excess amino acids?
Liver breaks down excess amino acids by deamination and are converted into urea
What are minerals?
。no energy value
。regulate metabolism
。forming body tissues
Name 3 examples of minerals.
Calcium, iron, iodine
What are the functions and deficiency disease of calcium?
Functions:
。form teeth and bones
。form blood clots
Deficiency disease:
。rickets (kids): bones turn soft and bends outwards
。osteoporosis (adults): bone becomes brittle
What are the functions and deficiency diseases of iron?
Functions:
。synthesize haemoglobin
Deficiency disease:
。anaemia: lack of haemoglobin -> faint easily
What are the functions and deficiency diseases of iodine?
Functions:
。maintain function of thyroid gland
Deficiency diseases:
。goitre: thyroid gland becomes swollen
What are vitamins?
。no energy value
。essential for maintaining normal functions of cells and organs
。regulate metabolism
。strengthen immunity
Name 3 examples of vitamins.
Vitamin A, vitamin C, vitamin D
What are the functions and deficiency diseases of vitamin A?
Functions:
。forms visual purple in rod cells in retina -> for night vision
。protect cornea
。strengthen immunity
Deficiency disease:
。night blindness
What are the functions and deficiency diseases of vitamin C?
Functions:
。synthesize + repair tissues for healing wounds
。strengthen immunity
Deficiency disease:
。scurvy
What are the functions and deficiency diseases of vitamin D?
Functions:
。promotes absorption of calcium and phosphate ions -> strong bones + teeth
Deficiency diseases:
。rickets (kids)
。osteoporosis (adults)
What are the functions and deficiency diseases of dietary fibres?
Functions:
。promote peristalsis
。soften faeces
。facilitate egestion
Deficiency diseases:
。constipation
What are the functions of water?
。main component of cytoplasm and blood
。medium for chemical reactions
。solvent for wastes
。make body secretions
。regulate body temperature (evaporation of sweat)
