# [[Epistemic status]]
#shower-thought
# Anabolism - Wikipedia
#to-digest
**Anabolism** () is the set of [metabolic pathways](https://en.wikipedia.org/wiki/Metabolic_pathway "Metabolic pathway") that construct [molecules](https://en.wikipedia.org/wiki/Molecules "Molecules") from smaller units.[\[1\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-1) These reactions require [energy](https://en.wikipedia.org/wiki/Energy "Energy"), known also as an [endergonic](https://en.wikipedia.org/wiki/Endergonic_reaction "Endergonic reaction") process.[\[2\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-2) Anabolism is the building-up aspect of [metabolism](https://en.wikipedia.org/wiki/Metabolism "Metabolism"), whereas [catabolism](https://en.wikipedia.org/wiki/Catabolism "Catabolism") is the breaking-down aspect. Anabolism is usually [synonymous](https://en.wikipedia.org/wiki/Synonym "Synonym") with [biosynthesis](https://en.wikipedia.org/wiki/Biosynthesis "Biosynthesis").
## Pathway\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=1 "Edit section: Pathway")\]
[Polymerization](https://en.wikipedia.org/wiki/Polymerization "Polymerization"), an anabolic pathway used to build macromolecules such as nucleic acids, proteins, and polysaccharides, uses [condensation reactions](https://en.wikipedia.org/wiki/Condensation_reaction "Condensation reaction") to join monomers.[\[3\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-MBC_2002-3) [Macromolecules](https://en.wikipedia.org/wiki/Macromolecule "Macromolecule") are created from smaller molecules using enzymes and [cofactors](https://en.wikipedia.org/wiki/Cofactor_(biochemistry) "Cofactor (biochemistry)").
[](https://en.wikipedia.org/wiki/File:Catabolism,_energy_carriers_and_anabolism.png)
Use of ATP to drive the endergonic process of anabolism.
### Energy source\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=2 "Edit section: Energy source")\]
Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in [cellular respiration](https://en.wikipedia.org/wiki/Cellular_respiration "Cellular respiration"). Many anabolic processes are powered by the [cleavage of adenosine triphosphate (ATP)](https://en.wikipedia.org/wiki/ATP_hydrolysis "ATP hydrolysis").[\[4\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-4) Anabolism usually involves [reduction](https://en.wikipedia.org/wiki/Redox "Redox") and decreases [entropy](https://en.wikipedia.org/wiki/Entropy "Entropy"), making it unfavorable without energy input.[\[5\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:0-5) The starting materials, called the precursor molecules, are joined using the [chemical energy](https://en.wikipedia.org/wiki/Chemical_energy "Chemical energy") made available from hydrolyzing ATP, reducing the cofactors [NAD+](https://en.wikipedia.org/wiki/Nicotinamide_adenine_dinucleotide "Nicotinamide adenine dinucleotide"), [NADP+](https://en.wikipedia.org/wiki/Nicotinamide_adenine_dinucleotide_phosphate "Nicotinamide adenine dinucleotide phosphate"), and [FAD](https://en.wikipedia.org/wiki/Flavin_adenine_dinucleotide "Flavin adenine dinucleotide"), or performing other favorable side reactions.[\[6\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-6) Occasionally it can also be driven by [entropy](https://en.wikipedia.org/wiki/Entropy "Entropy") without energy input, in cases like the formation of the [phospholipid bilayer](https://en.wikipedia.org/wiki/Lipid_bilayer "Lipid bilayer") of a cell, where hydrophobic interactions aggregate the molecules.[\[7\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-7)
### Cofactors\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=3 "Edit section: Cofactors")\]
The reducing agents [NADH](https://en.wikipedia.org/wiki/Nicotinamide_adenine_dinucleotide "Nicotinamide adenine dinucleotide"), [NADPH](https://en.wikipedia.org/wiki/Nicotinamide_adenine_dinucleotide_phosphate "Nicotinamide adenine dinucleotide phosphate"), and [FADH2](https://en.wikipedia.org/wiki/Flavin_adenine_dinucleotide "Flavin adenine dinucleotide"),[\[8\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:1-8) as well as metal ions,[\[3\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-MBC_2002-3) act as cofactors at various steps in anabolic pathways. NADH, NADPH, and FADH2 act as [electron carriers](https://en.wikipedia.org/wiki/Electron_carrier "Electron carrier"), while charged metal ions within enzymes stabilize charged [functional groups](https://en.wikipedia.org/wiki/Functional_group "Functional group") on [substrates](https://en.wikipedia.org/wiki/Substrate_(chemistry) "Substrate (chemistry)").
### Substrates\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=4 "Edit section: Substrates")\]
Substrates for anabolism are mostly intermediates taken from catabolic pathways during periods of high [energy charge](https://en.wikipedia.org/wiki/Energy_charge "Energy charge") in the cell.[\[9\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:2-9)
## Functions\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=5 "Edit section: Functions")\]
Anabolic processes build [organs](https://en.wikipedia.org/wiki/Organ_(biology) "Organ (biology)") and [tissues](https://en.wikipedia.org/wiki/Tissue_(biology) "Tissue (biology)"). These processes produce growth and differentiation of cells and increase in body size, a process that involves [synthesis](https://en.wikipedia.org/wiki/Chemical_synthesis "Chemical synthesis") of complex [molecules](https://en.wikipedia.org/wiki/Molecule "Molecule"). Examples of anabolic processes include the growth and mineralization of [bone](https://en.wikipedia.org/wiki/Bone "Bone") and increases in [muscle](https://en.wikipedia.org/wiki/Muscle "Muscle") mass.
### Anabolic hormones\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=6 "Edit section: Anabolic hormones")\]
[Endocrinologists](https://en.wikipedia.org/wiki/Endocrinologist "Endocrinologist") have traditionally classified [hormones](https://en.wikipedia.org/wiki/Hormone "Hormone") as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the [anabolic steroids](https://en.wikipedia.org/wiki/Anabolic_steroid "Anabolic steroid"), which stimulate protein synthesis and muscle growth, and [insulin](https://en.wikipedia.org/wiki/Insulin "Insulin").
### Photosynthetic carbohydrate synthesis\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=7 "Edit section: Photosynthetic carbohydrate synthesis")\]
[Photosynthetic carbohydrate synthesis](https://en.wikipedia.org/wiki/Photosynthesis "Photosynthesis") in plants and certain bacteria is an anabolic process that produces [glucose](https://en.wikipedia.org/wiki/Glucose "Glucose"), [cellulose](https://en.wikipedia.org/wiki/Cellulose "Cellulose"), [starch](https://en.wikipedia.org/wiki/Starch "Starch"), [lipids](https://en.wikipedia.org/wiki/Lipid "Lipid"), and [proteins](https://en.wikipedia.org/wiki/Protein "Protein") from CO2.[\[5\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:0-5) It uses the energy produced from the light-driven reactions of photosynthesis, and creates the precursors to these large molecules via [carbon assimilation](https://en.wikipedia.org/wiki/Carbon_fixation "Carbon fixation") in the [photosynthetic carbon reduction cycle](https://en.wikipedia.org/wiki/Light-independent_reactions "Light-independent reactions"), a.k.a. the Calvin cycle.[\[9\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:2-9)
[](https://en.wikipedia.org/wiki/File:Amino_acid_biosynthesis_overview.png)
Amino acid biosynthesis from intermediates of glycolysis and the citric acid cycle.
### Amino acid biosynthesis\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=8 "Edit section: Amino acid biosynthesis")\]
All amino acids are formed from intermediates in the catabolic processes of [glycolysis](https://en.wikipedia.org/wiki/Glycolysis "Glycolysis"), the [citric acid cycle](https://en.wikipedia.org/wiki/Citric_acid_cycle "Citric acid cycle"), or the [pentose phosphate pathway](https://en.wikipedia.org/wiki/Pentose_phosphate_pathway "Pentose phosphate pathway"). From glycolysis, [glucose 6-phosphate](https://en.wikipedia.org/wiki/Glucose_6-phosphate "Glucose 6-phosphate") is a precursor for [histidine](https://en.wikipedia.org/wiki/Histidine "Histidine"); [3-phosphoglycerate](https://en.wikipedia.org/wiki/3-Phosphoglyceric_acid "3-Phosphoglyceric acid") is a precursor for [glycine](https://en.wikipedia.org/wiki/Glycine "Glycine") and [cysteine](https://en.wikipedia.org/wiki/Cysteine "Cysteine"); [phosphoenol pyruvate](https://en.wikipedia.org/wiki/Phosphoenolpyruvic_acid "Phosphoenolpyruvic acid"), combined with the *3-phosphoglycerate*\-derivative [erythrose 4-phosphate](https://en.wikipedia.org/wiki/Erythrose_4-phosphate "Erythrose 4-phosphate"), forms [tryptophan](https://en.wikipedia.org/wiki/Tryptophan "Tryptophan"), [phenylalanine](https://en.wikipedia.org/wiki/Phenylalanine "Phenylalanine"), and [tyrosine](https://en.wikipedia.org/wiki/Tyrosine "Tyrosine"); and [pyruvate](https://en.wikipedia.org/wiki/Pyruvic_acid "Pyruvic acid") is a precursor for [alanine](https://en.wikipedia.org/wiki/Alanine "Alanine"), [valine](https://en.wikipedia.org/wiki/Valine "Valine"), [leucine](https://en.wikipedia.org/wiki/Leucine "Leucine"), and [isoleucine](https://en.wikipedia.org/wiki/Isoleucine "Isoleucine"). From the citric acid cycle, [α-ketoglutarate](https://en.wikipedia.org/wiki/Alpha-Ketoglutaric_acid "Alpha-Ketoglutaric acid") is converted into [glutamate](https://en.wikipedia.org/wiki/Glutamic_acid "Glutamic acid") and subsequently [glutamine](https://en.wikipedia.org/wiki/Glutamine "Glutamine"), [proline](https://en.wikipedia.org/wiki/Proline "Proline"), and [arginine](https://en.wikipedia.org/wiki/Arginine "Arginine"); and [oxaloacetate](https://en.wikipedia.org/wiki/Oxaloacetic_acid "Oxaloacetic acid") is converted into [aspartate](https://en.wikipedia.org/wiki/Aspartic_acid "Aspartic acid") and subsequently [asparagine](https://en.wikipedia.org/wiki/Asparagine "Asparagine"), [methionine](https://en.wikipedia.org/wiki/Methionine "Methionine"), [threonine](https://en.wikipedia.org/wiki/Threonine "Threonine"), and [lysine](https://en.wikipedia.org/wiki/Lysine "Lysine").[\[9\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:2-9)
### Glycogen storage\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=9 "Edit section: Glycogen storage")\]
During periods of high blood sugar, [glucose 6-phosphate](https://en.wikipedia.org/wiki/Glucose_6-phosphate "Glucose 6-phosphate") from glycolysis is diverted to the glycogen-storing pathway. It is changed to [glucose-1-phosphate](https://en.wikipedia.org/wiki/Glucose-1-phosphate "Glucose-1-phosphate") by [phosphoglucomutase](https://en.wikipedia.org/wiki/Phosphoglucomutase "Phosphoglucomutase") and then to [UDP-glucose](https://en.wikipedia.org/wiki/UDP-glucose "UDP-glucose") by [UTP--glucose-1-phosphate uridylyltransferase](https://en.wikipedia.org/wiki/UTP%E2%80%94glucose-1-phosphate_uridylyltransferase "UTP—glucose-1-phosphate uridylyltransferase"). [Glycogen synthase](https://en.wikipedia.org/wiki/Glycogen_synthase "Glycogen synthase") adds this UDP-glucose to a glycogen chain.[\[9\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:2-9)
### Gluconeogenesis\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=10 "Edit section: Gluconeogenesis")\]
[Glucagon](https://en.wikipedia.org/wiki/Glucagon "Glucagon") is traditionally a catabolic hormone, but also stimulates the anabolic process of [gluconeogenesis](https://en.wikipedia.org/wiki/Gluconeogenesis "Gluconeogenesis") by the liver, and to a lesser extent the kidney cortex and intestines, during starvation to prevent [low blood sugar](https://en.wikipedia.org/wiki/Hypoglycemia "Hypoglycemia").[\[8\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:1-8) It is the process of converting pyruvate into glucose. Pyruvate can come from the breakdown of glucose, [lactate](https://en.wikipedia.org/wiki/Lactic_acid "Lactic acid"), amino acids, or [glycerol](https://en.wikipedia.org/wiki/Glycerol "Glycerol").[\[10\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:3-10) The gluconeogenesis pathway has many reversible enzymatic processes in common with glycolysis, but it is not the process of glycolysis in reverse. It uses different irreversible enzymes to ensure the overall pathway runs in one direction only.[\[10\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:3-10)
## Regulation\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=11 "Edit section: Regulation")\]
Anabolism operates with separate enzymes from catalysis, which undergo irreversible steps at some point in their pathways. This allows the cell to regulate the rate of production and prevent an infinite loop, also known as a [futile cycle](https://en.wikipedia.org/wiki/Futile_cycle "Futile cycle"), from forming with catabolism.[\[9\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:2-9)
The balance between anabolism and catabolism is sensitive to [ADP](https://en.wikipedia.org/wiki/Adenosine_diphosphate "Adenosine diphosphate") and ATP, otherwise known as the energy charge of the cell. High amounts of ATP cause cells to favor the anabolic pathway and slow catabolic activity, while excess ADP slows anabolism and favors catabolism.[\[9\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-:2-9) These pathways are also regulated by [circadian rhythms](https://en.wikipedia.org/wiki/Circadian_rhythm "Circadian rhythm"), with processes such as [glycolysis](https://en.wikipedia.org/wiki/Glycolysis "Glycolysis") fluctuating to match an animal's normal periods of activity throughout the day.[\[11\]](https://en.wikipedia.org/wiki/Anabolism#cite_note-11)
## Etymology\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=12 "Edit section: Etymology")\]
The word *anabolism* is from [New Latin](https://en.wikipedia.org/wiki/New_Latin "New Latin"), with roots from [Greek](https://en.wikipedia.org/wiki/Greek_language "Greek language"): ἁνά, "upward" and βάλλειν, "to throw".
## References\[[edit](https://en.wikipedia.org/w/index.php?title=Anabolism&action=edit§ion=13 "Edit section: References")\]
1. **[^](https://en.wikipedia.org/wiki/Anabolism#cite_ref-1 "Jump up")** de Bolster MW (1997). ["Glossary of Terms Used in Bioinorganic Chemistry: Anabolism"](https://web.archive.org/web/20071030105041/http://www.chem.qmul.ac.uk/iupac/bioinorg/AB.html). International Union of Pure and Applied Chemistry. Archived from [the original](http://www.chem.qmul.ac.uk/iupac/bioinorg/AB.html#20) on 30 October 2007. Retrieved 2007-10-30.
2. **[^](https://en.wikipedia.org/wiki/Anabolism#cite_ref-2 "Jump up")** Rye C, Wise R, Jurukovski V, Choi J, Avissar Y (2013). [*Biology*](https://cnx.org/contents/
[email protected]:rZudN6XP@2/Introduction). Rice University, Houston Texas: OpenStax. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-1-938168-09-3](https://en.wikipedia.org/wiki/Special:BookSources/978-1-938168-09-3 "Special:BookSources/978-1-938168-09-3").
3. ^ [Jump up to: ***a***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-MBC_2002_3-0) [***b***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-MBC_2002_3-1) Alberts B, Johnson A, Julian L, Raff M, Roberts K, Walter P (2002). [*Molecular Biology of the Cell*](https://web.archive.org/web/20170927035510/https://www.ncbi.nlm.nih.gov/books/NBK21054/) (5th ed.). CRC Press. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-0-8153-3218-3](https://en.wikipedia.org/wiki/Special:BookSources/978-0-8153-3218-3 "Special:BookSources/978-0-8153-3218-3"). Archived from [the original](https://www.ncbi.nlm.nih.gov/books/NBK21054/) on 27 September 2017. Retrieved 2018-11-01. [Alt URL](https://archive.org/details/MolecularBiologyOfTheCell5th)
4. **[^](https://en.wikipedia.org/wiki/Anabolism#cite_ref-4 "Jump up")** Nicholls DG, Ferguson SJ (2002). *Bioenergetics* (3rd ed.). Academic Press. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-0-12-518121-1](https://en.wikipedia.org/wiki/Special:BookSources/978-0-12-518121-1 "Special:BookSources/978-0-12-518121-1").
5. ^ [Jump up to: ***a***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:0_5-0) [***b***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:0_5-1) Ahern K, Rajagopal I (2013). [*Biochemistry Free and Easy*](https://biochem.science.oregonstate.edu/files/biochem/ahern/BiochemistryFreeandEasy3.pdf) (PDF) (2nd ed.). Oregon State University.
6. **[^](https://en.wikipedia.org/wiki/Anabolism#cite_ref-6 "Jump up")** Voet D, Voet JG, Pratt CW (2013). *Fundamentals of biochemistry : life at the molecular level* (Fourth ed.). Hoboken, NJ: Wiley. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-0-470-54784-7](https://en.wikipedia.org/wiki/Special:BookSources/978-0-470-54784-7 "Special:BookSources/978-0-470-54784-7"). [OCLC](https://en.wikipedia.org/wiki/OCLC_(identifier) "OCLC (identifier)") [738349533](https://www.worldcat.org/oclc/738349533).
7. **[^](https://en.wikipedia.org/wiki/Anabolism#cite_ref-7 "Jump up")** Hanin I, Pepeu G (2013-11-11). *Phospholipids: biochemical, pharmaceutical, and analytical considerations*. New York. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-1-4757-1364-0](https://en.wikipedia.org/wiki/Special:BookSources/978-1-4757-1364-0 "Special:BookSources/978-1-4757-1364-0"). [OCLC](https://en.wikipedia.org/wiki/OCLC_(identifier) "OCLC (identifier)") [885405600](https://www.worldcat.org/oclc/885405600).
8. ^ [Jump up to: ***a***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:1_8-0) [***b***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:1_8-1) Jakubowski H (2002). ["An Overview of Metabolic Pathways - Anabolism"](https://bio.libretexts.org/TextMaps/Biochemistry/Book%3A_Biochemistry_Online_(Jakubowski)/10%3A_Metabolic_Pathways/B._MP2%3A_An_Overview_of_Metabolic_Pathways_-_Anabolism). *Biochemistry Online*. College of St. Benedict, St. John's University: LibreTexts.
9. ^ [Jump up to: ***a***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:2_9-0) [***b***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:2_9-1) [***c***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:2_9-2) [***d***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:2_9-3) [***e***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:2_9-4) [***f***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:2_9-5) Nelson DL, Lehninger AL, Cox MM (2013). *Principles of Biochemistry*. New York: W.H. Freeman. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-1-4292-3414-6](https://en.wikipedia.org/wiki/Special:BookSources/978-1-4292-3414-6 "Special:BookSources/978-1-4292-3414-6").
10. ^ [Jump up to: ***a***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:3_10-0) [***b***](https://en.wikipedia.org/wiki/Anabolism#cite_ref-:3_10-1) Berg JM, Tymoczko JL, Stryer L (2002). [*Biochemistry*](https://archive.org/details/biochemistrychap00jere) (5th ed.). New York: W.H. Freeman. [ISBN](https://en.wikipedia.org/wiki/ISBN_(identifier) "ISBN (identifier)") [978-0-7167-3051-4](https://en.wikipedia.org/wiki/Special:BookSources/978-0-7167-3051-4 "Special:BookSources/978-0-7167-3051-4"). [OCLC](https://en.wikipedia.org/wiki/OCLC_(identifier) "OCLC (identifier)") [48055706](https://www.worldcat.org/oclc/48055706).
11. **[^](https://en.wikipedia.org/wiki/Anabolism#cite_ref-11 "Jump up")** Ramsey KM, Marcheva B, Kohsaka A, Bass J (2007). "The clockwork of metabolism". *Annual Review of Nutrition*. **27**: 219–40. [doi](https://en.wikipedia.org/wiki/Doi_(identifier) "Doi (identifier)"):[10.1146/annurev.nutr.27.061406.093546](https://doi.org/10.1146%2Fannurev.nutr.27.061406.093546). [PMID](https://en.wikipedia.org/wiki/PMID_(identifier) "PMID (identifier)") [17430084](https://pubmed.ncbi.nlm.nih.gov/17430084).