Use of ketones: Difference between revisions
From WikiLectures
Gypsophila (talk | contribs) (Created page with "Využití ketolátek Ketolátky jsou produktem rozkladu mastných kyselin za určitých metabolických podmínek (např. hladovění). Mezi ketolátky patří acetacetát, b...") |
No edit summary |
||
| (9 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
'''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]] | |||
<noinclude> | |||
== 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 [[Krebs cycle]]. | |||
== 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''' % of its energy requirements are covered by the oxidation of ketones. | |||
== Links == | |||
=== Related Articles === | |||
*[[Ketones]] | |||
*[[Ketones in the urine]] | |||
*[[Ketones in the urine/determination]] | |||
=== External links === | |||
Ketolátky (česká wikipedie) | *[https://cs.wikipedia.org/wiki/Ketol%C3%A1tky| Ketolátky (česká wikipedie)] | ||
[[Category:Biochemistry]] | |||
[[Category:FBLT]] | |||
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.
