system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to meat when it cooks?

On a molecular level, what happens?
gpt
Proteins, which are molecules that generally speaking are specifically folded up chains of amino acids, denature and become tangled.  Fat deposits in adipose tissue, and oils and stuff stored in vesicles like liposomes, melt and are released as their containers fail and get squeezed out by the meat shrinking.  The meat shrinks probably from a combination of protein denaturation, cell breakdown, and dehydration as water is driven out.  

Most meat is muscle tissue with a bit of adipose, and muscle is very enriched in strands of protein involved in motion, so these strands in particular would become disordered. dehydrated, stick together more, etc.  At a larger scale, muscle is also a collection of oriented cells that form fibres, and the connective tissue that holds together these fibres made from muscle cells breaks down, making the meat easier to break apart.