Chapter 23 (Ketone Bodies) Flashcards
Catalase
peroxisomes have a high concentration of these and it is used to detoxify peroxides (H2O2)
Thiolase
Converts 2 acetyl-CoAs into Acetoacetyl CoA
Produces: HSCoA
Reversible
HMG-CoA Synthetase
Attaches another Acetyl-CoA onto the alpha carbon to create 3-Hydroxy-3-Methylglutaryl CoA
Requires: Acetyl-CoA + H2O
Produces: HSCoA
Reversible
HMG-CoA Lyase
Removes an Acetyl-CoA to produce Acetoacetate
Produces: Acetyl-CoA
Irreversible
Two fates of Acetoacetate
can become a ketone body
can become acetone (a waste product)
Beta-Hydroxybuturate Hydrogenase
Adds an H to the carbonyl group producing the ketone body: Beta-3-Hydroxybutyrate (Beta-HB)
Requires: NADH+H
Produces: NAD+
Reversible
(T/F) A ketone body does not need to have a ketone in it
True
Under ___ conditions Acetyl-CoA is converted into ketone bodies
gluconeogenic
Ketone bodies are the fuel of choice for the ___ and can also fuel the ___
heart muscle
muscles
Under starvation conditions, ketone bodies become the main fuel source for the ___
brain
Ketone bodies are essentially ___ FAs that:
water soluble
circulate in the blood stream
Ketone bodies are only synthesized in the
mitochondrial matrix of liver tissues
First step to catabolizing the ketone body Alpha-3-Hydroxybutyrate
Using the reverse rxn: Beta-Hydroxybutyrate DH Generates 2.5 ATP Creates Acetoacetate Requires: NAD+ Produces: NADH+H Reversible
CoA Transferase
Transfers a CoA from Succinyl-CoA onto Acetoacetate to create Acetoacetyl-CoA Costs 1 ATP (GTP) Requires: Succinyl-CoA Produces: Succinate Irreversible
Thiolase
Brings in a CoA and breaks Acetoacyl-CoA into two Acetyl-CoAs
Requires: HSCoA
