Every breath you take and nearly every meal you eat traces back to a single quiet chemical trick that plants, algae and some bacteria perform: turning sunlight, water and air into food. This episode unpacks photosynthesis, arguably the most important chemical reaction on Earth.

You'll come away understanding how a leaf captures light, where the oxygen we breathe actually comes from, why plants are green, and how this one process built our breathable atmosphere and underpins almost every food chain.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Khan Academy – "Photosynthesis"; NASA Earth Observatory – "The carbon cycle"; David Attenborough, *The Green Planet*.