very low barrier. Bicycloalkanes are alkanes containing two rings that are connected to each other by sharing two carbon atoms. Orientation within bicycloalkanes is dependent on the cis or trans orientation of the hydrogen shared by the different rings instead of the methyl groups present in the rings. Tetrodotoxin is one of the world's most potent toxins. It is made up of multiple six member rings set in chair conformations, with each ring but one containing an atom other than carbon. See also Cyclohexane conformation Conformational isomerism References External links Conformations of Alkanes & Cycloalkanes Molecular geometry Stereochemistry