CHEMISTRY OF LIFE- GRADE 10

SCIENCE CENTRE Lesson 2
CHEMISTRY OF LIFE GRADE 10
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Molecules (compound) are made up of atoms (elements). (E.g. Sodium
chloride (NaCl) consist of sodium (Na) & chlorine (Cl))
Inorganic molecules, e.g. water (H2O) & minerals (Na, K, Ca, nitrates, etc.)
Organic molecules are made up of C, H, and O, & other elements, such as
N&P
Cells are made up of proteins, carbohydrates, lipids, nucleic acids (DNA
& RNA) and vitamins.
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Inorganic Compounds
1. Functions of WATER (2H + O ↔ H2O)
§ Water is a universal solvent for all substances in the cells/organism
§ Serve as a medium for chemical reactions to take place in (metabolism)
§ Water transport all substances in blood
§ Serve as lubricant (e.g. in digestive system)




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LIFE SCIENCE GR.10

, SCIENCE CENTRE Lesson 2
2. MACRO- & MICRO-ELEMENTS /MINERALS/SALTS
o Macro-elements are required by the organism in large quantities.
o Micro-elements are required in small quantities.

Ï MACRO- AND MICRO- ELEMENTS IN MAMMALS/HUMANS
ELEMENT FUNCTION/IMPORTANCE DEFICIENCY SOURCES
Mg Diary, leafy
(magnesium) vegetables, nuts,
Bone & tooth structure RACHITIS: Limited bananas & eggs
Ca Functioning of nervous system growth, Poor bones Diary & leafy
(calcium) & teeth vegetables
P Diary, leafy
(phosphorous) vegetables, meat, fish
& egg yolk
Na Needed for osmoregulation: Loss in body mass, Table salt (NaCl)
(sodium) regulate water volume in body Bad nervous system
(kidneys)
S Produce proteins like keratin BLOOD CLOTS: Meat, fish & legumes
(sulphur) (hair & nails) & heparin (blood Closed up blood (beans & peas)
clotting) vessels
N Produce proteins Limited growth, Meat, fish, legumes,
(nitrogen) Component of nucleic acids (DNA KWASHIORKOR milk & eggs
& RNA) (no proteins)
Fe Production: haemoglobin (blood) ANAEMIA: Too few Liver, green
(iron) red blood cells = low vegetables, egg yolk,
O2 = fatigue meat & raisins
I Functioning of thyroid gland GOITRE: Thyroid Sea food (e.g. fish,
(iodine) Regulate chemical reactions / gland in neck swells mussels, calamari) &
metabolism up, low metabolism iodated salt

Ï MACRO- AND MICRO- ELEMENTS IN PLANTS
ELEMENT FUNCTION/IMPORTANCE DEFICIENCY SOURCES
C Soil
(carbon) Photosynthesis Poor growth
H2 Found in all organic molecules Break down H2O
(hydrogen)
O2 Cellular Respiration Plant dies Atmosphere
(oxygen) Found in some organic molecules (21% O2)
P Component of cell membranes & Poor growth, Soil
(phosphorous) nucleic acids leaves fall off
N Needed for the production of CHLOROSIS: Soil, Atmosphere (79%
(nitrogen) chlorophyll (green pigment used leaves turn yellow, N2) & Lightning
S for photosynthesis) poor roots Soil
(sulphur)
Fe Needed to produce chlorophyll CHLOROSIS: Soil
(iron) (green pigment in leaves) leaves turn yellow


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LIFE SCIENCE GR.10

, SCIENCE CENTRE Lesson 2
3. FERTILISERS
§ Fertilisers contain micro- and macro-
elements that increases plant growth




§ Overuse of fertilisers cause it to run off into rivers when it rains
§ In water, fertilisers cause eutrophication (increase bacteria & decrease O2)
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LIFE SCIENCE GR.10