The fifth taste

Factual Questions
1

Inspired by this article from BBC Science:

Bitter we get from various alkaloid/alkaline(??) things. Sour from acidic ones. Sweet from sugar - and things that imitate sugar. Salty just from salt? (and salt substitutes?)

So does the MSG taste just come from MSG? Does MSG occur naturally in some plant or meat foods, if so, what? And what exactly does it taste of, because I thought it was just a flavour enhancer to open up your tastebuds to help you taste other things more?

2

They’ve givena name to that taste: umami.

3

It’s basically the difference between salt water and broth. Here’s an interesting article about broth that explains some of the chemistry: