Protein & Amino Acid Metabolism Flashcards
(19 cards)
What stimulates the uptake of amino acids into skeletal muscle, adipose tissue and the liver?
Insulin and growth hormone
What is the difference between ketogenic and glucose in amino acids?
The carbon skeleton is converted into alpha ketoglutarate
Vs succinate, fumerate, oxaloacetate, acteyl co A, pyruvate
What are the different avenues for protein excretion?
Urea 85%
Creatine 5%
Sweat as uric acid
Ammonia
When phenylalanine concentration falls what amino acid becomes essential?
Tyrosine
When methionine concentration falls, what amino acid becomes essential?
Cysteine
What occurs in transamination ?
A.a 1 + k.a 2 = A.a 2 + K. A 1
What are the two transaminases enzyme concentrations used to identify liver damage?
Alanine transaminase and aspartate transaminase
ALT and AST
What are the products of ALT?
Pyruvate and glutamate
What are the products of AST (aspartate transaminase)
Glutamate and oxoaloacetate
What are d amino acid oxidises?
They oxidase d amino acids so they aren’t used for protein synthesis because the proteins would be faulty.
what is Creatininine?
What can a high level indicate?
The breakdown product of creatine and creatin phosphate, present in urine in direct concentration to muscle mass.
Skeletal Muscle damage
What does a positive nitrogen balance indicate?
Growth, pregnancy, recovering from malnutrition
What is a negative nitrogen balance?
When the protein output is greater than input indicating trauma or infection.
What is PKU?
What test is there for it?
A hereditary disease causing faulty phenylalanine hydroxylase causing increased phenyl pyruvate concentrations
that results in impaired brain development as phenyl pyruvate prevents the uptake of pyruvate from mitochondria.
Newborn heel prick test
What compound is the toxic one in PKU?
What is the enzyme?
Phenyl pyruvate
Phenyl hydroxylase
What is homocystinuria?
Defect in methionine metabolism due to enzyme deficiency causing high {homocysteine} in blood.
Results in disorders in CT and muscle
How does high [ammonia] affect the CNS
The metabolism uses alpha ketoglutarate, reducing turns of TCA and thus energy produced for brain cells
How is ammonia processed?
Converted to urea in livers
Or used to synthesis glutamine where it is taken to the kidney and excreted as ammonia
What enzyme in the neutrophil is responsible for synthesising ROS (superoxide) for respiratory bursts?
Membrane bound NADPH-oxidase
