Final answer:
Chromatin transforms from the less condensed euchromatin into tightly packed heterochromatin by binding proteins, especially histones, and condensing into a 30 nm fiber with additional non-histone proteins. Condensin aids in further condensation to form the metaphase chromosome structure for cell division.
Step-by-step explanation:
During interphase, chromatin exists in two forms: euchromatin which is less condensed and associated with active gene transcription, and heterochromatin which is more condensed and associated with gene silencing. The transition from euchromatin to heterochromatin involves the binding of various proteins to chromatin. At the most basic level, DNA is wrapped around histone proteins to form nucleosomes, often likened to 'beads on a string.' This structure can then condense into a 30 nm fiber, and further folding and accumulation of non-histone proteins facilitate the formation of chromatin into tightly packed heterochromatin.
During the prophase of cell division, chromatin undergoes significant condensation to facilitate the distribution of chromosomes to daughter cells. The enzyme condensin plays a crucial role in this process by contributing to the coiling of DNA into the highly condensed metaphase chromosome structure. This compacted form is essential for the proper segregation of chromosomes during mitosis or meiosis.