It helps keep sharks afloat, but may be partly responsible for their declining numbers: Helen Scales introduces squalene

Nathan Adams introduces a confusingly-named protein that's essential for keeping blood flowing: Albumin

Neil Withers finds out how vermilion has been keeping human civilisation looking bright and beautifully red for centuries

Brian Clegg holds his nose to examine one of the real workhorses of the organic chemistry lab: Pyridine

Nathan Adams investigates some of the most important molecular machines within our cells, the cytochrome p450 enzymes

Brian Clegg reminisces about indoor fireworks and Vesuvian fire with this week's compound: Ammonium dichromate

Meet melatonin, the 'Dracula of hormones', essential in regulating the body's natural circadian rhythm

Once a fusty way of keeping moths out of clothes, Brian Clegg explains how naphthalene may have helped bring life to Earth

Nature has a range of ways to create bioluminescence. Not to be outdone, chemists create their own glow with diphenyl oxalate.

They are the compounds that link leather trousers to a nice cup of tea - Brian Clegg introduces tannins