u/Comfortable_World_69

• Green dots are unpaired native electrons that delocalize.
• Yellow dots are electrons not native to the atom

upper left:

• nitrogen, carbon monoxide, cyanide, & acetylene which are isoelectronic
• ozone
• carbon dioxide
• formic acid
• thioformic acid
• hydrogen sulfide
• formamide
• formaldehyde & methanol
• ammonia
• hexamine

lower left:

• ethylene
• fatty acid
• ethylamine
• glycolipid
• retinal (cf coenzyme Q10)

upper right:

• iron-sulfur cluster
• amino acids

lower right:

• calcium carbonate
• phosphate
• citric acid
• pyruvate
• guanidine + cyanide
• urea

bottom:

• uroporphyrinogen
• 2 aminolevulinic acid molecules (glycine and succinyl-CoA) becoming porphobilinogen (4 of which become uroporphyrinogen)