Identifying molecular composition?

[NotABiologist]

Hello. I've always wondered how the chemical composition/molecular composition of biological systems were identified. Maybe I can explain that better by saying that in metallurgy, we use X-ray diffraction, electron diffraction, energy dispersive spectroscopy....technologies that either rely on long range order such as crystal lattices or take advantage of electrons being excited such that energies can me measured. (We always have problems with light elements such as C and H.)

How does your community start with an unknown and identify it? Let's see...I was in a discussion about enzymes, and such, related to bacteria. So how do you ID an new enzyme or even a hormone?

I remember about |<=>| that much organic chemistry and we definitely didn't get into this area of "how did you figure that out?"

[rambobala]

biologist always start with

1.hypothesis:-think about a situation in vivo and present a hypothesis(eg.evolution)
2.imitation model:-imitation of the system invitro or in a test tube
so we can ensure what are missing
(eg.dna synthesis)
3.limitation:-removing a thing there by blocking its function(eg.vitamines)
4.fools proof:-proving the theory from hypothesis model

for these steps biology requires knowledge from basic sciences namely physics and chemistry and importantly from maths