Similarly, when {HEAD ~ the pH} of the environment falls below the pH of {TAIL ~ the protein}, the protein has a net positive charge 
Similarly , when { HEAD ~ the pH } of the environment falls below the pH of { TAIL ~ the protein } , the protein has a net positive charge
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH