Editing Side chain (section)

{{short description|Chemical group attached to backbone}}
{{About|the chemistry term|other uses|Side-chain (disambiguation)}}
{{About|the side chain of any type of long molecule|replacement of a hydrogen atom on a hydrocarbon chain|Substituent}}

{{Quote box
|title=[[International Union of Pure and Applied Chemistry|IUPAC]] definition
|quote='''Branch'''<br>'''Side-chain'''<br>'''Pendant chain'''<br>An [[oligomer]]ic or [[polymer]]ic offshoot from a [[macromolecular]] chain.

''Notes''

# An oligomeric branch may be termed a ''short-chain branch''.
# A polymeric branch may be termed a ''long-chain branch''.<ref>{{cite journal |title=Glossary of basic terms in polymer science (IUPAC Recommendations 1996) |journal=[[Pure and Applied Chemistry]] |year=1996 |volume=68 |issue=12 |pages=2287–2311 |doi=10.1351/pac199668122287 |url=http://pac.iupac.org/publications/pac/pdf/1996/pdf/6812x2287.pdf |last1=Jenkins |first1=A. D. |last2=Kratochvíl |first2=P. |last3=Stepto |first3=R. F. T. |last4=Suter |first4=U. W. |s2cid=98774337}}</ref> 
}}

In [[organic chemistry]] and [[biochemistry]], a '''side chain''' is a [[substituent|chemical group]] that is attached to a core part of the molecule called the "main chain" or [[backbone chain|backbone]]. The side chain is a [[hydrocarbon]] branching element of a molecule that is attached to a larger hydrocarbon backbone. It is one factor in determining a molecule's properties and reactivity.<ref>{{cite book |last=Wade |first=L.G. |url=https://archive.org/details/organicchemistry00wade_1 |title=Organic Chemistry, 7th Edition |publisher=Pearson Prentice Hall |year=2010 |isbn=978-0-321-59231-6 |location=Upper Saddle River, NJ |pages=70–78 |url-access=registration}}</ref> A side chain is also known as a '''pendant chain''', but a [[pendant group]] (side group) has a different definition.