[20] ALT and AST Transamination Flashcards
What are ALT and AST?
They are enzymes involved in transamination, a key process in amino acid metabolism.
What does ALT stand for?
Alanine Aminotransferase
What does AST stand for?
Aspartate Aminotransferase
What is the role of ALT in transamination?
ALT facilitates the transfer of an amino group from Alanine to α-Ketoglutarate.
What is the role of AST in transamination?
AST facilitates the transfer of an amino group from Aspartate to α-Ketoglutarate.
Where is ALT mainly found?
In the liver.
Where is AST mainly found?
In the liver, heart, skeletal muscle, kidneys, brain, and red blood cells.
Why are ALT and AST levels in the blood significant?
Elevated levels can indicate damage to tissues where these enzymes are abundant, particularly the liver.
What is the reaction catalyzed by ALT?
Alanine + α-Ketoglutarate ⇌ Pyruvate + Glutamate
What is the reaction catalyzed by AST?
Aspartate + α-Ketoglutarate ⇌ Oxaloacetate + Glutamate
How are ALT and AST related to the urea cycle?
They play a role in removing excess nitrogen from the body.
What is the clinical significance of a high ALT/AST ratio in the blood?
It can indicate liver damage, such as that caused by alcohol abuse or viral hepatitis.
What does “transaminase” mean?
It’s an enzyme that catalyzes a type of reaction called transamination.
What is Pyruvate?
A key intermediate in several metabolic pathways.
What is Glutamate?
An amino acid that plays a key role in protein synthesis and other metabolic processes.
What is Oxaloacetate?
A metabolite in the citric acid cycle.
Why is transamination important?
It helps the body maintain balance between different amino acids and produce non-essential amino acids.
How do the body’s cells use the products of the reactions catalyzed by ALT and AST?
They use them to generate ATP, synthesize new proteins, and carry out other metabolic functions.
How are ALT and AST levels in the blood measured?
Through a simple blood test, often part of a comprehensive metabolic panel.
