Use of ketones: Difference between revisions
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'''Ketones''' are products of the breakdown of [[fatty acids]] under certain metabolic conditions (e.g. starvation). Ketones include acetoacetate, beta-hydroxybutyrate, and [[acetone]]. They are created only in the liver and are used by extrahepatic tissues as a temporary source of energy. | |||
'''Ketones''' are products of the breakdown of fatty acids under certain metabolic conditions (e.g. starvation). Ketones include acetoacetate, beta-hydroxybutyrate, and [[acetone]] . They are created only in the liver and are used by extrahepatic tissues as a temporary source of energy. | |||
[[File:Scheme of individual ketones - acetone, acetoacetate and beta-hydroxybutyrate.png|thumb|Scheme of individual ketones - acetone, acetoacetate and beta-hydroxybutyrate]] | |||
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== Chemical processes == | == Chemical processes == | ||
Ketones are '''polar''' and are therefore freely transported '''in the plasma''' . Their utilization occurs only '''extrahepatically''' , because hepatocytes do not contain the enzyme required for their activation. First, '''β-hydroxybutyrate is oxidized to acetoacetate''' , which is subsequently activated by the transfer of coenzyme A from succinyl~CoA . Acetocetyl~CoA is '''converted to AcCoA''' (part of β-oxidation, catalyzed by thiolase), which enters the | Ketones are '''polar''' and are therefore freely transported '''in the plasma'''. Their utilization occurs only '''extrahepatically''', because hepatocytes do not contain the enzyme required for their activation. First, '''β-hydroxybutyrate is oxidized to acetoacetate''' , which is subsequently activated by the transfer of coenzyme A from succinyl~CoA . Acetocetyl~CoA is '''converted to AcCoA''' (part of β-oxidation, catalyzed by thiolase), which enters the [[Krebs cycle]]. | ||
== Use of ketones by individual organs == | == Use of ketones by individual organs == | ||
Cardiac muscle, skeletal muscle and renal cortex '''prefer ketone''' oxidation over glucose oxidation. During starvation, the brain adapts '''to the burning of ketones''' - during long-term starvation, up to '''50''' | Cardiac muscle, skeletal muscle and renal cortex '''prefer ketone''' oxidation over glucose oxidation. During starvation, the brain adapts '''to the burning of ketones''' - during long-term starvation, up to '''50''' % of its energy requirements are covered by the oxidation of ketones. | ||
== Links == | == Links == | ||
=== Related Articles === | === Related Articles === | ||
[[Ketones]] | *[[Ketones]] | ||
*[[Ketones in the urine]] | |||
*[[Ketones in the urine/determination]] | |||
=== External links === | |||
*[https://cs.wikipedia.org/wiki/Ketol%C3%A1tky| Ketolátky (česká wikipedie)] | |||
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[[Category:Biochemistry]] | |||
[[Category:FBLT]] | |||
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Latest revision as of 12:24, 18 December 2022
Ketones are products of the breakdown of fatty acids under certain metabolic conditions (e.g. starvation). Ketones include acetoacetate, beta-hydroxybutyrate, and acetone. They are created only in the liver and are used by extrahepatic tissues as a temporary source of energy.
Chemical processes[edit | edit source]
Ketones are polar and are therefore freely transported in the plasma. Their utilization occurs only extrahepatically, because hepatocytes do not contain the enzyme required for their activation. First, β-hydroxybutyrate is oxidized to acetoacetate , which is subsequently activated by the transfer of coenzyme A from succinyl~CoA . Acetocetyl~CoA is converted to AcCoA (part of β-oxidation, catalyzed by thiolase), which enters the Krebs cycle.
Use of ketones by individual organs[edit | edit source]
Cardiac muscle, skeletal muscle and renal cortex prefer ketone oxidation over glucose oxidation. During starvation, the brain adapts to the burning of ketones - during long-term starvation, up to 50 % of its energy requirements are covered by the oxidation of ketones.
