cistranscis

Cistranscis is a term used in chemistry and biology to describe the spatial arrangement of atoms or groups of atoms around a central atom or bond. The prefix "cis" refers to the arrangement where two groups are on the same side of the central bond or atom, while "trans" refers to the arrangement where the groups are on opposite sides. The term is often used to describe the stereochemistry of molecules, particularly in organic chemistry.

In organic chemistry, cistranscis isomerism is a type of stereoisomerism that occurs when a molecule has two or more double bonds or functional groups that can exist in different spatial arrangements. For example, in the molecule but-2-ene, there are two possible cistranscis isomers: cis-but-2-ene, where the two methyl groups are on the same side of the double bond, and trans-but-2-ene, where the methyl groups are on opposite sides.

Cistranscis isomerism is important in biology, particularly in the study of proteins and nucleic acids. The spatial arrangement of amino acids in a protein chain can affect its function, and the cistranscis arrangement of nucleotides in DNA can influence gene expression. Understanding cistranscis isomerism is therefore crucial in fields such as pharmacology, biochemistry, and molecular biology.