Lecture 31: Amino Acid Catabolism Flashcards
What are the two primary structures that degrade proteins in cells
Proteasome
Lysosome
Identity of the amino acid at what terminal determines the rate of ubiquination
N-terminal amino acid identity
Proteasome is what type of enzyme
ATPase
What is the coenzyme used during deamination
Pyridoxal phosphate
What two enzymes are used in deamination of most amino acids
Aminotransferase
Glutamate dehydrogenase
Which two amino acids are deaminated by only one enzyme (direct deamination), and what is its name
Serine, Threonine
Dehydratase
Serine is deaminated to form what
Pyruvate
What does Aspartate aminotransferase (AST/SGOT) do
Catalyzes interconversion of Aspartate and Oxaloacetate
What does Alanine Aminotransferase (ALT/SGPT) do
Catalyzes interconversion of Alanine and Pyruvate
What amino acid is commonly used in deamination
Glutamate
What is a common toxic byproduct of amino acid deamination/catabolism
Ammonia
Where does the urea cycle take place
In the liver
What is the committed step in the urea cycle and what enzyme catalyzes it
Creation of carbamoyl phosphate by combining CO2 and NH3
-Catalyzed by carbamoyl phosphate synthetase I
What is an allosteric activator of CPSI (Carbamoyl phosphate synthetase I)
NAG
What is ornithines significance in the urea cycle
It is created with Urea is removed from Arginine.
It moves into the mitochondria and combines with Carbamoyl phosphate to form citrulline, which is then exported from the mitochondria
After aspartate donates an NH3, what does it become
Fumarate
What cycle is used to convert fumarate to oxaloacetate
Citric acid cycle
Which amino acids can be converted to pyruvate
Serine Threonine Glycine Alanine Cysteine
Which amino acids can be converted to Oxaloacetate
Asparagine
Aspartate
Which amino acids are converted to a-ketoglutarate
Glutamine Glutamate Proline Arginine Histidine
Which amino acids are converted to Succinyl CoA
Methionine
Valine
Isoleucine
Which amino acids are ketogenic only
Leucine
Lysine
Where is carbamoyl phosphate produced in urea cycle
Mitochondria
Where is ornithine produced in urea cycle
Cytosol
