BIOL 1300 Lecture 4: Interactions in Phase-Separated States
Document Summary
Phase diagrams: shows transition points between the states of matter, dotted lines show coexistence points where two states can exist at the same itme. Water has an anomalous liquid-solid phase transition --> this is why ice floats: variables for water: temperature, pressure. But for biological molecules, concentration and temperature and ph are more important. Protein phase transitions: molecules will coalesce into phases, when you have lots of one kind of molecule in one phase and depleted in the other phase, creation of phase boundaries. Dynamic - molecules can cross phase diagram but no net change. Types and examples: rna granules or ribonucleoprotein (rnp) granules, cytosolic examples. Functions of non-membrane bound organelles: rna metabolism: storage, splicing, decapping, degradation, not currently clear . Granule composition: proteins: up to dozens of distinct proteins, rna: various mrna depending on granule function. Characteristics: dynamic: protein and rna enter/leave, liquid: fuse and flow.
