Multiple choice The unit structure of gap junctions is named as connexin. What is not true about it? An aspect of connexins is that they have a relatively short half life of only a few hours. Connexins are also called as gap junctions. Connexins contain only single termini. The connexin gene family is diverse, with twenty-one identified members in the sequenced human genome. It is in the ER that connexins are properly folded, yielding two extracellular loops. Reveal answer Fill a bubble to check yourself C Correct answer Explanation Connexins are four-pass transmembrane proteins with both C and N cytoplasmic termini.