Urea Cycle Flashcards
Urea Cycle Big Picture

3 Transaminations

Vitamin B6 and AA Metabolism

What other enzyme requires vitamin b6?
Glucokinase
Glycogen Phosphorylase
Pyruvate Dehydrogenase
G6P dehaydrogenas
Fatty Ayl CoA Synthetase
Glycogen Phosphorylase
Muscle Degredation of Protein Will Occur under which of the following Conditions?
After a high fat low carb meal
During prolonged fasting
After a high carb low protein meal
During shorter anaerobic exercise
After a high fat low carb meal — This might be accepted much further downstream.
During prolonged fasting
Muscle Degredation of Amino Acids

Ammonia Metabolism in Liver

Enzymes involved in Nitrogen Metabolism

Flow of Nitrogen

Glutamine Synthetase
Glutamine Synthetas is found in the cytoplasm.

Glutaminase
So is Glutaminase (found in the cytosol).

Glutamate Dehydrogenase

Why is Ammonia Toxic?

Nervous System and Amino Acids

Synthesis of Carbamoyl Phosphate

Urea Cycle Pathway

Compartmentation in the Urea Cycle

TCA Urea Cycle Interactions

Where does Ornithine Come From?

Regulation of the Urea Cycle

What other pathway exhibited long term adaptation?
Glycolysis
Gluconeogenesis
Fatty acid Syntehisis
Fatty Acid Oxidation
Fatty acid Syntehisis
Allosteric Regulation of the Urea Cycle

Pathway for Regulation of Urea Cycle

N-Acetyl Glutamate Synthetase Deficiency and CPS- Deficiency

Ornithine Transcarbamoylase Deficiency

Continued Disorders of the Urea Cycle

Arginase Defect

Potential Treatment for urea cycle disorders could include which of the following?
Take aspirin
Taking essential amino acids
Taking Alpha keto acids of essential amino acids
Increasing the protein content of diet
Decreasing Carbohydrate Intake
Taking Alpha keto acids of essential amino acids — leads to reduced ammonia levels.
Treatment for Urea Cycle Disorders

Hypercitrullinemia Type II

Nitrogen Balance

Case Study

Ornithine Transcarbamylase deficiency
A Healthy individualstarts a diet which had adequate calories but lacks one essential amino acid. What happens to their nitrogen balance?
Neutral Nitrogen Balance
Positive Nitrogen Balance
Negative Nitrogen Balance
Negative Nitrogen Balance