1. Compiled by Group 3 : Immanuelle Orchidea, Rohsi Purnama Sari, Nugroho Windu
Hadi

2. =O
CH3-C-CH2-COO
- -
acetoacetate
OH
CH3-C-CH2-COO
H
D-β-hydroxybutyrate
CH3-C-CH3
=O
acetone

3. 


Acetoacetate : if not oxidized to form usable
energy, used as source of two other ketone
bodies
Acetone : cannot be used by brain for energy.
Generated through decarboxylation of
acetoacetate (enzyme : acetoacetate
decarboxylase) released by breathing it off, or
via urine excretion.
D-β-hydroxybutyrate : generated through the
action of the enzyme D-β-hydroxybutyrate
dehydrogenase on acetoacetate

4.  Produced as “by-products” from
breakdown of fatty acids in liver.
 Acetoacetic acid & D-β-hydroxybutyric
acid used as energy source in heart and
brain
( during fasting/ low blood-glucose
conditions)
 Acetone = waste product= EXCRETED!!!

5.  Modification of acetyl coA from fat
catabolism into ketone bodies, to be
delivered into other peripheral
tissues, then turn into CO2 and H2O
by oxidation process. (Lehninger
pg.213)
 Other tissues : brain tissues, etc.

6. Oxidation in
mitochondria
Fatty
acyl
coA
Alteration into
triacylglicerol &
phospholipid by
enzymatic reactions in
cytosol
Oxidation of
acetyl coA in TCA
cycle
Alteration into
ketone bodies

7. 





Produced from acetyl CoA mainly in the
mitochondrial matrix of hepatocytes
Scarcity of carbohydrate -> fatty acid breakdown->
obtain energy
High level acetyl coA -> pyruvate dehydrogenase
complex is inhibited-> pyruvate carboxylase
activated.
High level of ATP & NADH inhibit the enzyme
isocitrate dehydrogenase in TCA cycle->increasing of
malate.
High level of NADH & ATP -> B-oxidation
Excess of acetyl coA-> rerouted to ketogenesis

8. 

Low level of blood glucose : exhaustion,
fasting, sleeping, etc. -> body still needs
energy -> breakdown the fatty acid into
ketone bodies
Excessive of blood glucose -> unable to be
stored as glycogen -> fatty acid

9. 2 Acetyl-S-CoA  acetoacetyl-S-CoA + CoA-SH
acetoacetyl-S-CoA + H2O  acetoacetate + coA-SH
D-β-hydroxybutyrate dehidrogenase
Acetoacetate + NADH + H+ D-β-hydroxybutyrate + NAD+
Delivered to peripheral tissues

10. acetoacetyl-S-CoA + H2O  acetoacetate + coA-SH
CoA-SH + H+
=O
=O
CH3-C-CH2-C-S-CoA + CH3-CO-S-CoA
H2O
Hydroxymethyl-glutarylCoA synthase

11. - ---
COO
CH2
HO-C-CH2
CH2
β-hydroxy βmethylglutaryl-CoA
=O
C-S-CoA
Hydroxymethyl-glutarylCoA lyase
=O
CH3-C-CH2-COO
Acetoacetate
+ CH3-CO-S-CoA
+
acetyl CoA

12. D-β-hydroxybutyrate dehidrogenase
D-β-hydroxybutyrate + NAD+  Acetoacetate + NADH + H+
3-ketoacyl-CoA transferase
Succynil-S-CoA + Acetoacetate  succinate +
acetoacetyl-S-CoA
NEXT

13. tiolase
acetoacetyl-S-CoA + CoA-SH 2 Acetyl-S-CoA