Topic 3

Most frequently occurring elements in organisms.
Carbon, Hydrogen, Oxygen, Nitrogen
Other essential elements.
Sulfur, Calcium, Phosphorus, Iron, Sodium
Role of Sulfur
Role of Calcium
Prokaryotes: flagella movement
Plants: forms cell plate during cytokinesis
Animals: shells, bones, teeth and vesicle fusion with membranes
Role of Phosphorus
Nucleic acids and ATP
Role of Iron
Prokaryotes: cytochrome used in respiration
Plants: cytochrome used in mitochondrial respiration
Animals: cytochrome used in mitochondrial respiration and haemoglobin
Role of Sodium
Plants: main cation in cytoplasm
Animals: transmission of nerve impulses
simple sugars: glucose, galactose, fructose
two monosaccharides: maltose, lactose, sucrose
long chains of monosaccharides: starch, glycogen, cellulose
Function of glucose (animals)
Broken down in respiration to release energy.
Function of fructose (plants)
Energy source and component of sucrose.
Function of lactose (animals)
Sugar in milk produced by mammals.
Function of sucrose (plants)
Unreactive and so transported in the plant.
Function of glycogen (animals)
Energy store in liver and skeletal muscles.
Function of cellulose (plants)
Main component of cell wall.