1.
Urea Cycle
• Urea is the major disposal form of nitrogen
• 90% of the nitrogen containing component of urine
• It takes place in liver
• Urea is transported through blood to kidneys for
excretion in urine.

2.
Sources of Ammonia
• From Glutamine
• From bacterial action in intestine
• From amines
• From purines and pyrimidines

3.
Transport of Ammonia in
circulation
• Glutamine and alanine
• Glutamine synthetase is abundant in liver , skeletal
muscles, CNS.

4.
(NH2)2CO
• Source of nitrogen >>> ammonia + Aspartate
• Source of carbon and oxygen>>> bicarbonate
• Utilization of 1 H2O molecule
• Utilization of 3 ATP molecules
• Products : urea and fumarate

5.
Regulation
• Short term >>> substrate availability
• Long term >>> Enzyme induction

6.
Ornithine transcarbamoylase
The only x linked
All others >>> autosomal recessive

7.
Hyperammonia
• Normal 3-35micromoles/litre
• 1000 micromoles/l

8.
ammonia has a direct neurotoxic
effect on the CNS. For example, elevated
concentrations of ammonia in the blood cause
the symptoms of ammonia intoxication, which
include tremors, slurring of speech,
somnolence (drowsiness), vomiting, cerebral
edema, and blurring of vision. At high
concentrations,
ammonia can cause coma and death.

9.
There are 2 types
• Acquired>>> liver diseases
• Congenital>>>Enzymic deficiency

10.
Let's take a review

11.
Thank you 💕