I thought that as we walk down the next part of the gully we’d have a look at air – there’s some, look, right in front of your nose. You can’t see, smell, taste or touch it so what exactly is it? Mainly it’s a mixture of two elements (not a compound – they don’t combine together). The two elements are Nitrogen (78%) and Oxygen (21%). The other 1% contains other elements, primarily Argon.
Every breath you take (don’t worry – I’m not going to start singing again) is for the most part Nitrogen, a vital element for us but the problem is; we can’t use it directly. We need plants to do a bit of work for us like this Rosularia serrata here. It can’t use Nitrogen from the air either, it needs help from special bacteria in the soil that use enzymes to convert the nitrogen into organic compounds that it takes up through its roots. We, and other animals, can then take the nitrogen that we need to produce things like essential amino acids from the plants that we eat. When it, and we, die we pass the nitrogen back into the soil for reprocessing by bacteria.
Read on at http://bit.ly/2hg9Wm5