Heat and pressure deep beneath earth's surface can change any rock into

Six amino acids have side chains that are polar but not charged. these are serine (ser), threonine (thr), cysteine (cys), asparagine (asn), glutamine (gln), and tyrosine (tyr). these amino acids are usually found at the surface of proteins, as discussed in the proteins 2 module.

He should put sand around the spill in order to contain it so that it won't spread