Fully identify the subunit composition of a protein from the following information. Molecular mass by gel filtration: 350 kD Molecular mass by SDS-PAGE: 200 kD and 150 kD Molecular mass by SDS-PAGE with 2-mercaptoethanol: 100 kD, 80 kD, and 70 kD -S-S- is a disulfide bond and [ ][ ] are non-covalent associations A). [100-S-S-100][80-S-S-70] B). [100-S-S-80][100-S-S-70] C). [100-S-S-100-S-70][80] D). [100-S-S-100-S-80][70] E). [100-S-S-100-S-70-S-S-80]

organisms are more likely to be more preserved in mud than sand because mud is moist and wet, while sand is very dry.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.