'Sy chemmig, ta formley kemmigagh çheet er y vollagh raad ta fysseree bentyn rish coreiryn kemmigagh ny breneenyn ta jannoo co-vunstoo ny co-vreneen er lheh currit roish, goaill ymmyd jeh cowraghyn kemmigagh, earrooyn, as cowraghyn elley, lheid as eddyraishnyssyn, skilleigyn, cammagyn, as ny cowraghyn moojey (+) as loojey (−). T'ad currit sheese ayns un linney clougraafagh jeh cowraghyn, foddee goaill stiagh fo-screeuyn as harrish-screeuyn. Cha nee ennym kemmigagh eh formley kemmigagh er-yn-oyr nagh vel fockle erbee ayn. Ga dy vel formley kemmigagh cowraghey strughtooryn kemmigagh neuchramp, cha nel eh ny 'ormley strughtooragh kemmigagh. Foddee formlaghyn kemmigagh enmyssey strughtooryn ny co-vreneenyn as stooghyn kemmigagh s'oney ny lomarcan, as ta'd caglit er çheu ny h-enmyn kemmigagh as ny formlaghyn stughtooragh.

Y formley kemmigagh da sulfaid ollymin
Y formley strughtooragh da biootane

Ta ny formlaghyn kemmigagh s'oney enmyssit formlaghyn treealagh, as t'ad goaill ymmyd jeh lettyryn as earrooyn as ad shassoo er son coreiryn earrooagh ny breneenyn. Ta formlaghyn co-vreneenagh shassoo er son ny h-earrooyn oney jeh dagh sorçh dy vreneen ayns co-vreneen, gyn fys ayn bentyn rish y strughtoor. Myr sampleyr, she CH2O y formley treealagh da glucose (daa cheayrt ny smoo breneenyn jeh hiddragien na breneenyn carboan ny ocsygien), agh she C6H12O6 (12 vreneen hiddragien, shey breneenyn carboan as ocsygien) y formley co-vreneenagh.

Keayrtyn ta formley kemmigagh jeant co-chast tra t'eh screeuit myr formley giarrit (ny formley co-vreneenagh giarrit, ta enmyssit "formley lieh-strughtooragh" keayrtyn), as t'ad cur tooilley fysseree roish bentyn rish y vollagh raad ta ny breneenyn reaghit as kianglt ry-cheilley, foddee ayns kianglaghyn co-fioosagh, kianglaghyn eeaneagh, ny mestagheyn eigsoylagh jeh'n daa chiangley shen. T'eh shen jantagh my vel eh aashagh y kiangley bentynagh y haishbyney ayns un towshan. Myr sampleyr, jeeagh er yn 'ormley co-vreneenagh/kemmigagh giarrit da ethanoal CH3−CH2−OH ny CH3CH2OH. Ansherbee, ta formley kemmigagh giarrit caglit rere y jargaght echey kianglaghyn co-chast eddyr breneenyn y haishbyney, breneenyn ta kianglt rish kiare fo-stooghyn ny ny smoo er lheh.

Er-yn-oyr dy vel formlaghyn kemmigagh screeuit myr un linney jeh cowraghyn kemmigagh, cha nel y mooad fysseree ayndaue bentyn rish y formley strughtooragh firrinagh, ta ny hoylley graafagh jeh'n vooinjerys reamyssagh eddyr ny breneenyn ayns co-vunstooghyn (jeeagh er ny sampleyryn jeh ny formlaghyn strughtooragh as kemmigagh da biootane çheu yesh). Kyndagh rish cooishyn castaght strughtooragh, foddee un ormley kemmigagh giarrit co-reggyrt rish co-vreneenyn eigsoylagh, ta enmyssit isomeyryn. Myr sampleyr, ta glucose rheynn e ormley co-vreneenagh C6H12O6 lesh ram shugyryn elley, goaill stiagh fructose, galactose as mannose. Ta enmyn kemmigagh linnagh corrym ayn ta enmyssey formley strughtooragh co-chast erbee (jeeagh er enmyssey kemmigagh), agh lhisagh ny h-enmyn shen goaill ymmyd jeh ram hçiarrymyn (focklyn) ayns ynnyd ny cowraghyn, earrooyn, as clouyn oney elley ta ry-akin ayns formlaghyn kemmigagh.