Editing Chlorophyll (section)

==Chemical structure==
[[Image:Chlorophyll-a-3D-vdW.png|thumb|Space-filling model of the chlorophyll&nbsp;''a'' molecule]]
Several chlorophylls are known. All are defined as derivatives of the parent [[chlorin]] by the presence of a fifth, ketone-containing ring beyond the four pyrrole-like rings. Most chlorophylls are classified as [[chlorin]]s, which are reduced relatives of [[porphyrins]] (found in [[hemoglobin]]). They share a common biosynthetic pathway with porphyrins, including the precursor [[uroporphyrinogen III]]. Unlike hemes, which contain iron bound to the N4 center, most chlorophylls bind [[magnesium]]. The axial [[ligand]]s attached to the Mg<sup>2+</sup> center are often omitted for clarity. Appended to the chlorin ring are various side chains, usually including a long [[phytyl]] chain ({{chem2|C20H39O}}). The most widely distributed form in terrestrial plants is chlorophyll ''a''. Chlorophyll ''a'' has [[methyl]] group in place of a [[formyl]] group in chlorophyll ''b''. This difference affects the absorption spectrum, allowing plants to absorb a greater portion of visible light.

The structures of chlorophylls are summarized below:<ref>{{cite book |doi=10.1007/1-4020-4516-6_1 |chapter=An Overview of Chlorophylls and Bacteriochlorophylls: Biochemistry, Biophysics, Functions and Applications |title=Chlorophylls and Bacteriochlorophylls |series=Advances in Photosynthesis and Respiration |year=2006 | vauthors = Scheer H |volume=25 |pages=1–26 |isbn=978-1-4020-4515-8 }}</ref><ref>{{cite journal | vauthors = Taniguchi M, Lindsey JS | title = Synthetic Chlorins, Possible Surrogates for Chlorophylls, Prepared by Derivatization of Porphyrins | journal = Chemical Reviews | volume = 117 | issue = 2 | pages = 344–535 | date = January 2017 | pmid = 27498781 | doi = 10.1021/acs.chemrev.5b00696 | osti = 1534468 }}</ref>{{clear}}

{| class="wikitable"
|
! [[Chlorophyll a|Chlorophyll ''a'']]
! [[Chlorophyll b|Chlorophyll ''b'']]
! [[Chlorophyll c1|Chlorophyll ''c<sub>1</sub>'']]
! [[Chlorophyll c2|Chlorophyll ''c<sub>2</sub>'']]
! [[Chlorophyll d|Chlorophyll ''d'']]
! [[Chlorophyll f|Chlorophyll ''f'']]<ref name=ChlF />
|-
! [[Molecular formula]]
| C<sub>55</sub>H<sub>72</sub>O<sub>5</sub>N<sub>4</sub>Mg
| C<sub>55</sub>H<sub>70</sub>O<sub>6</sub>N<sub>4</sub>Mg
| C<sub>35</sub>H<sub>30</sub>O<sub>5</sub>N<sub>4</sub>Mg
| C<sub>35</sub>H<sub>28</sub>O<sub>5</sub>N<sub>4</sub>Mg
| C<sub>54</sub>H<sub>70</sub>O<sub>6</sub>N<sub>4</sub>Mg
| C<sub>55</sub>H<sub>70</sub>O<sub>6</sub>N<sub>4</sub>Mg
|-
! C2 group
| [[methyl group|−CH<sub>3</sub>]]
| −CH<sub>3</sub>
| −CH<sub>3</sub>
| −CH<sub>3</sub>
| −CH<sub>3</sub>
| −CHO
|-
! C3 group
| [[Vinyl group|−CH=CH<sub>2</sub>]]
| −CH=CH<sub>2</sub>
| −CH=CH<sub>2</sub>
| −CH=CH<sub>2</sub>
| [[formyl|−CHO]]
| −CH=CH<sub>2</sub>
|-
! C7 group
| −CH<sub>3</sub>
| −CHO
| −CH<sub>3</sub>
| −CH<sub>3</sub>
| −CH<sub>3</sub>
| −CH<sub>3</sub>
|-
! C8 group
| [[ethyl group|−CH<sub>2</sub>CH<sub>3</sub>]]
| −CH<sub>2</sub>CH<sub>3</sub>
| −CH<sub>2</sub>CH<sub>3</sub>
| −CH=CH<sub>2</sub>
| −CH<sub>2</sub>CH<sub>3</sub>
| −CH<sub>2</sub>CH<sub>3</sub>
|-
! C17 group
| −CH<sub>2</sub>CH<sub>2</sub>COO−Phytyl
| −CH<sub>2</sub>CH<sub>2</sub>COO−Phytyl
| [[acrylate|−CH=CHCOOH]]
| −CH=CHCOOH
| −CH<sub>2</sub>CH<sub>2</sub>COO−Phytyl
| −CH<sub>2</sub>CH<sub>2</sub>COO−Phytyl
|-
! C17−C18 bond
| Single<br />(chlorin)
| Single<br />(chlorin)
| Double<br />(porphyrin)
| Double<br />(porphyrin)
| Single<br />(chlorin)
| Single<br />(chlorin)
|-
! Occurrence
| Universal
| Mostly plants
| Various algae
| Various algae
| Cyanobacteria
| Cyanobacteria
|}
<div class="skin-invert-image><gallery caption="Structures of chlorophylls">
chlorophyll a.svg|chlorophyll ''a''
chlorophyll b.svg|chlorophyll ''b''
chlorophyll c1.svg|chlorophyll ''c<sub>1</sub>''
chlorophyll c2.svg|chlorophyll ''c<sub>2</sub>''
Chlorophyll d.svg|chlorophyll ''d''
Chlorophyll f_vert.svg|chlorophyll ''f''
</gallery></div>

Chlorophyll ''e'' is reserved for a pigment that has been extracted from algae in 1966 but not chemically described. Besides the lettered chlorophylls, a wide variety of sidechain modifications to the chlorophyll structures are known in the wild. For example, ''[[Prochlorococcus]]'', a cyanobacterium, uses 8-vinyl Chl ''a'' and ''b''.<ref name="Chen19">{{cite journal | vauthors = Chen M |title=Chlorophylls d and f: Synthesis, occurrence, light-harvesting, and pigment organization in chlorophyll-binding protein complexes |journal=Advances in Botanical Research |date=2019 |volume=90 |pages=121–139 |doi=10.1016/bs.abr.2019.03.006|isbn=9780081027523 |s2cid=149632511 }}</ref>