In cis isomers, how are the groups positioned?

Cis isomers are characterized by the positioning of their substituent groups relative to a double bond or a ring structure in a molecule. In the case of cis isomers, two identical or similar groups are located on the same side of the structure, which results in a specific spatial configuration. This unique arrangement influences the physical and chemical properties of the isomer, such as boiling points and polarity, making it distinct from trans isomers, where the groups would be on opposite sides.

This understanding of spatial arrangements is crucial in biochemistry, as many biological molecules function through stereochemistry, and the distinction between cis and trans configurations can greatly affect their interactions and functionality in biological systems.