Editing Haptophyte (section)

==Characteristics==
[[File:2023_Haptophyte.jpg|center|thumb|upright=2|{{center|'''Representation of a  haptophyte'''}}{{ordered list|Haptonema, for movement|
Flagellar [[Basal body|basal bodies]]|
[[Flagellum]]|
Surface scale|
Alveolae, surface cavities or pits|
[[Mitochondria|Mitochondrion]], creates [[Adenosine triphosphate|ATP]] (energy) for the cell|
[[Golgi apparatus]], modifies [[protein]]s and sends them out of the cell|
Nascent scales|
[[Endoplasmic reticulum]], the transport network for molecules going to specific parts of the cell|
Plastidial endoplasmic reticulum|
Periplastidial membrane|
Outer and inner [[plastid]] membranes|
[[Thylakoid]], site of the [[light-dependent reactions]] of [[photosynthesis]]|
[[Pyrenoid]], center of [[carbon fixation]]|
[[Cell nucleus|Nucleus]]|
[[Lysosome]], holds enzymes|
[[Phagosome|Phagocytic vacuole]] with prey}}]]

The [[chloroplast]]s are pigmented similarly to those of the [[heterokont]]s,<ref>{{cite journal | vauthors = Andersen RA | title = Biology and systematics of heterokont and haptophyte algae | journal = American Journal of Botany | volume = 91 | issue = 10 | pages = 1508–22 | date = October 2004 | pmid = 21652306 | doi = 10.3732/ajb.91.10.1508 }}</ref> but the structure of the rest of the cell is different, so it may be that they are a separate line whose chloroplasts are derived from similar [[red algae|red algal]] endosymbionts. Haptophyte chloroplasts contain chlorophylls [[Chlorophyll a|a]], [[Chlorophyll_c#Chlorophyll_c1|c<sub>1</sub>]], and [[Chlorophyll_c#Chlorophyll_c2|c<sub>2</sub>]] but lack chlorophyll [[Chlorophyll_b|b]]. For carotenoids, they have [[beta-carotene|beta-]], [[Α-Carotene|alpha-]], and [[γ-Carotene|gamma-]] carotenes. Like [[diatoms]] and [[brown algae]], they have also [[fucoxanthin]], an oxidized isoprenoid derivative that is likely the most important driver of their brownish-yellow color.<ref name="l415">{{cite book | last=Margulis | first=L. | last2=Chapman | first2=M.J. | title=Kingdoms and Domains: An Illustrated Guide to the Phyla of Life on Earth | chapter=Pr-25 Haptomonada | publisher=Academic Press | year=2009 | isbn=978-0-08-092014-6 | url=https://books.google.com/books?id=9IWaqAOGyt4C | access-date=2024-11-12 | page=}}</ref>

The cells typically have two slightly unequal [[flagellum|flagella]], both of which are smooth, and a unique organelle called a '''haptonema''', which is superficially similar to a flagellum but differs in the arrangement of [[microtubule]]s and in its use.  The name comes from the [[Greek language|Greek]] ''hapsis'', touch, and ''nema'', round thread.  The [[mitochondrion|mitochondria]] have tubular [[crista]]e.

Most haptophytes reportedly produce [[chrysolaminarin]] rather than [[starch]] as their major storage polysaccharide, but some [[Pavlovaceae]] produce [[paramylon]].<ref name="d311">{{cite book | last=Tsuji | first=Yoshinori | last2=Yoshida | first2=Masaki | title=Advances in Botanical Research | chapter=Biology of Haptophytes: Complicated Cellular Processes Driving the Global Carbon Cycle | publisher=Elsevier | volume=84 | date=2017 | isbn=978-0-12-802651-9 | doi=10.1016/bs.abr.2017.07.002 | page=219–261}}</ref><ref name="x389">{{cite journal | last=Penot | first=Mathias | last2=Dacks | first2=Joel B. | last3=Read | first3=Betsy | last4=Dorrell | first4=Richard G. | title=Genomic and meta-genomic insights into the functions, diversity and global distribution of haptophyte algae | journal=Applied Phycology | volume=3 | issue=1 | date=2022-12-31 | issn=2638-8081 | doi=10.1080/26388081.2022.2103732 | doi-access=free | pages=340–359}}</ref> The chain length of the chrysolaminarin is reportedly short (polymers of 20–50 glycosides, unlike the 300+ of comparable [[amylose]]), and it is located in cytoplasmic membrane-bound vacuoles.<ref name="x389">{{cite journal | last=Penot | first=Mathias | last2=Dacks | first2=Joel B. | last3=Read | first3=Betsy | last4=Dorrell | first4=Richard G. | title=Genomic and meta-genomic insights into the functions, diversity and global distribution of haptophyte algae | journal=Applied Phycology | volume=3 | issue=1 | date=2022-12-31 | issn=2638-8081 | doi=10.1080/26388081.2022.2103732 | doi-access=free | pages=340–359}}</ref>