Editing Polysaccharide (section)

==Storage polysaccharides==

=== Starch ===
{{main|Starch}}
[[Starch]] is a [[glucose]] polymer in which [[glucopyranose]] units are bonded by ''alpha''-linkages. It is made up of a mixture of [[amylose]] (15–20%) and [[amylopectin]] (80–85%). Amylose consists of a linear chain of several hundred glucose molecules, and Amylopectin is a branched molecule made of several thousand glucose units (every chain of 24–30 glucose units is one unit of Amylopectin). Starches are [[insoluble]] in [[water]]. They can be digested by breaking the ''alpha''-linkages (glycosidic bonds). Both humans and other animals have amylases so that they can digest starches. [[Potato]], [[rice]], [[wheat]], and [[maize]] are major sources of starch in the human diet. The formations of starches are the ways that plants store [[glucose]].<ref>{{Cite journal |last1=Pfister |first1=Barbara |last2=Zeeman |first2=Samuel C. |date=July 2016 |title=Formation of starch in plant cells |journal=Cellular and Molecular Life Sciences |language=en |volume=73 |issue=14 |pages=2781–2807 |doi=10.1007/s00018-016-2250-x |pmid=27166931 |issn=1420-682X|pmc=4919380 }}</ref>

===Glycogen===
{{main|Glycogen}}

Glycogen serves as the secondary long-term energy storage in [[animal]] and [[fungi|fungal]] cells, with the primary energy stores being held in [[adipose tissue]]. Glycogen is made primarily by the [[liver]] and the [[muscle]]s, but can also be made by [[glycogenesis]] within the [[brain]] and [[stomach]].<ref>{{cite book | title = Anatomy and Physiology | vauthors = Saladin KS | publisher = McGraw-Hill | date = 2007 }}</ref>

Glycogen is analogous to [[starch]], a glucose polymer in [[plant]]s, and is sometimes referred to as ''animal starch'',<ref>{{cite encyclopedia | url=http://www.merriam-webster.com/medical/animal%20starch | title=Animal starch | dictionary=Merriam Webster | access-date=May 11, 2014}}</ref> having a similar structure to [[amylopectin]] but more extensively branched and compact than starch. Glycogen is a polymer of α(1→4) glycosidic bonds linked with α(1→6)-linked branches. Glycogen is found in the form of granules in the [[cytosol]]/cytoplasm in many [[cell (biology)|cell]] types and plays an important role in the [[glucose cycle]]. Glycogen forms an [[energy]] reserve that can be quickly mobilized to meet a sudden need for glucose, but one that is less compact and more immediately available as an energy reserve than  [[triglycerides]] (lipids).{{Citation needed|date=February 2021}}

In the liver [[hepatocyte]]s, glycogen can compose up to 8 percent (100–120&nbsp;grams in an adult) of the fresh weight soon after a meal.<ref name="Campbell 2006">{{cite book | vauthors = Campbell NA, Williamson B, Heyden RJ | title = Biology: Exploring Life | publisher = Pearson Prentice Hall | year = 2006 | location = Boston, Massachusetts | url = http://www.phschool.com/el_marketing.html | isbn = 978-0-13-250882-7 }}</ref> Only the glycogen stored in the liver can be made accessible to other organs. In the [[muscle]]s, glycogen is found in a low [[concentration]] of one to two percent of the muscle mass. The amount of glycogen stored in the body—especially within the [[muscles]], [[liver]], and [[red blood cells]]<ref>{{cite journal | vauthors = Moses SW, Bashan N, Gutman A | title = Glycogen metabolism in the normal red blood cell | journal = Blood | volume = 40 | issue = 6 | pages = 836–43 | date = December 1972 | pmid = 5083874 | doi = 10.1182/blood.V40.6.836.836 | url = http://www.bloodjournal.org/cgi/pmidlookup?view=long&pmid=5083874 | doi-access = free }}</ref><ref name="INGERMANN & VIRGIN, 1987">{{cite journal| vauthors = Ingermann RL, Virgin GL |title=Glycogen Content and Release of Glucose from Red blood cells of the Sipunculan Worm Themiste Dyscrita|url=http://jeb.biologists.org/cgi/reprint/129/1/141.pdf|journal=Journal of Experimental Biology|access-date=July 21, 2017|date=January 20, 1987|volume=129|issue=1 |pages=141–149|doi=10.1242/jeb.129.1.141|bibcode=1987JExpB.129..141I }}</ref><ref>{{cite journal | vauthors = Miwa I, Suzuki S | title = An improved quantitative assay of glycogen in erythrocytes | journal = Annals of Clinical Biochemistry | volume = 39 | issue = Pt 6 | pages = 612–3 | date = November 2002 | pmid = 12564847 | doi = 10.1258/000456302760413432 }}</ref>—varies with physical activity, [[basal metabolic rate]], and eating habits such as [[intermittent fasting]]. Small amounts of glycogen are found in the [[kidney]]s and even smaller amounts in certain [[glial]] cells in the [[brain]] and [[white blood cells]]. The [[uterus]] also stores glycogen during pregnancy to nourish the embryo.<ref name="Campbell 2006"/>

Glycogen is composed of a branched chain of glucose residues. It is primarily stored in the liver and muscles.<ref>{{Cite journal |last1=Ørtenblad |first1=N. |last2=Nielsen |first2=J. |date=2015 |title=Muscle glycogen and cell function – Location, location, location |url=https://onlinelibrary.wiley.com/doi/10.1111/sms.12599 |journal=Scandinavian Journal of Medicine & Science in Sports |language=en |volume=25 |issue=S4 |pages=34–40 |doi=10.1111/sms.12599 |issn=0905-7188}}</ref>
* It is an energy reserve for animals.
* It is the chief form of carbohydrate stored in animal organisms.
* It is insoluble in water. It turns brown-red when mixed with iodine.
* It also yields glucose on [[hydrolysis]].

<gallery mode="packed" heights="200px">
File:Glycogen structure.svg|Schematic 2-D cross-sectional view of glycogen. A core protein of [[glycogenin]] is surrounded by branches of [[glucose]] units. The entire globular granule may contain approximately 30,000 glucose units.<ref>{{cite book | url = https://books.google.com/books?id=SRptlOx7yj4C | page = 12 | title = Exercise physiology: energy, nutrition, and human performance | vauthors = McArdle WD, Katch FI, Katch VL | edition = 6th | publisher = Lippincott Williams & Wilkins | date = 2006 | isbn = 978-0-7817-4990-9 }}</ref>
File:Glycogen spacefilling model.jpg|A view of the [[atom]]ic structure of a single branched strand of [[glucose]] units in a glycogen [[molecule]].
</gallery>

=== Galactogen ===
'''Galactogen''' is a polysaccharide of [[galactose]] that functions as energy storage in [[Pulmonata|pulmonate]] snails and some [[Caenogastropoda]].<ref>{{cite book | vauthors = Goudsmit EM | date = 1972 | chapter = Carbohydrates and carbohydrate metabolism in Mollusca | veditors = Florkin M, Scheer BT | title = Chemical Zoology | volume = VII Mollusca | publisher = Academic Press | location = New York | pages = 219–244 }}</ref> This polysaccharide is exclusive of the reproduction and is only found in the albumen gland from the female snail reproductive system and in the [[perivitelline fluid]] of egogens have applications within hydrogel structures. These hydrogel structures can be designed to release particular nanoparticle pharmaceuticals and/or encapsulated therapeutics over time or in response to environmental stimuli.<ref>{{cite journal | last1=Hoare | first1=Todd | last2=Babar | first2=Ali | title=In situ gelling polysaccharide-based nanoparticle hydrogel compositions, and methods of use thereof | url=https://pubchem.ncbi.nlm.nih.gov/patent/US-2021361570-A1 | journal=PubChem | volume=1 | issue=1 }}</ref>

Formed by crosslinking polysaccharide-based [[nanoparticle]]s and functional polymers, galactogens have applications within hydrogel structures. These hydrogel structures can be designed to release particular nanoparticle pharmaceuticals and/or encapsulated therapeutics over time or in response to environmental stimuli.<ref>{{cite journal |last1=Hoare |first1=Todd |last2=Babar |first2=Ali |title=In situ gelling polysaccharide-based nanoparticle hydrogel compositions, and methods of use thereof |url=https://pubchem.ncbi.nlm.nih.gov/patent/US-2021361570-A1 |journal=PubChem |volume=1 |issue=1}}</ref>

Galactogens are polysaccharides with binding affinity for [[bioanalytes]]. With this, by end-point attaching galactogens to other polysaccharides constituting the surface of medical devices, galactogens have use as a method of capturing bioanalytes (e.g., CTC's), a method for releasing the captured bioanalytes and an analysis method.<ref>{{cite journal | last1=Wiegman | first1=Peter | last2=Mulder | first2=Hans | title=A process for applying a coating comprising one or more polysaccharides with binding affinity for bioanalytes onto the surface of a medical sampling device, and the medical sampling device for capture of bioanalytes provided with the coating | url=https://pubchem.ncbi.nlm.nih.gov/patent/WO-2022034027-A1 | journal=PubChem | volume=1 | issue=1 | pages = 101–104  }}</ref>

=== Inulin ===
{{main|Inulin}}

[[Inulin]] is a naturally occurring polysaccharide [[complex carbohydrate]] composed of [[fructose]], a plant-derived food that human digestive enzymes cannot completely break down. The inulins belong to a class of [[dietary fiber]]s known as [[fructan]]s. Inulin is used by some plants as a means of storing energy and is typically found in [[root]]s or [[rhizome]]s. Most plants that synthesize and store inulin do not store other forms of carbohydrates such as [[starch]]. In the United States in 2018, the [[Food and Drug Administration]] approved inulin as a dietary fiber ingredient used to improve the [[nutrition]]al value of manufactured food products.<ref>{{Cite web |date=14 June 2018 |title=The Declaration of Certain Isolated or Synthetic Non-Digestible Carbohydrates as Dietary Fiber on Nutrition and Supplement Facts Labels: Guidance for Industry |publisher=U.S. [[Food and Drug Administration]] |url=https://www.fda.gov/downloads/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/UCM610144.pdf}}</ref>