Explain why the following conditions are necessary for photosynthesis a) Carbon (IV) Oxide

Required in the dark stage of photosynthesis; it combines with the hydrogen ion from the light stage; to form glucose, proteins and lipids; low concentrations reduces the rate of production of energy and food; while high concentrations leads to an increase in the amount of energy and food formed;

b) Light

It is used to break down water molecules (through photolysis); into hydrogen ions, oxygen and energy; the energy and hydrogen ions formed are used in the dark stage;

c) Chlorophyll

Green pigment that traps light energy from the sun; that is used in photolysis of water molecules;

d) Suitable temperature and pH

Temperature affects the enzymes involved in photosynthesis; suitable/optimum temperatures activate enzymes; for maximum production of food; while extremely low temperatures inactivate enzymes; leading to less or no production of food; high temperatures denature enzymes; stopping the process of photosynthesis; photosynthetic enzymes work well in low pH; so the rate is high; while higher pH reduces enzyme activity; lowering the rate of photosynthesis; 

e) Water 

Forms a medium for the chemical reactions; it is split to yield hydrogen ions, oxygen and energy for use in the dark stage; solvent for the materials used in photosynthesis;