Protein and Amino Acid Metabolism Flashcards
(30 cards)
What are the 3 components of the amino acid pool?
Body Protein
Dietary Protein
Synthesized Nonessential Amino Acids
What is defective in patients suffering from Hartnup Disease?
What does this lead to?
Defective transport of nonpolar or neutral amino acids like Tryptophan. Leads to an increased levels in the urine.
Leads to a failure to thrive in infants,
What is defective in patients suffering from Cystinuria? What does this lead to?
Defective transport of dimeric cystine and basic amino acids such as Arginine and Lysine
This leads to cystine crystals in the kidneys AKA kidney stones
What are the Essential Amino Acids?
PVT TIM HALL
Phenylalanine
Valine
Threonine
Tryptophan
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
What is the function of enteropeptidases/enterokinases?
To cleave trypsinogen into the active form of trypsin
Which 2 amino acids are ketogenic?
Leucine
Lysine
What are the 5 amino acids that are both glucogenic and ketogenic?
Phenylalanine Isoleucine Tryptophan Threonine Tyrosine
What are the amino acids that are only glucogenic?
Find this out by process of elimination cause there are a lot of these.
What are transamination molecules? What are 2 examples used?
Molecules that transfer amino groups to an alpha-ketoacid
Aspartate + Alpha-ketoglutarate -> Glutamate + Oxaloacetate (This is encouraged by the enzyme Aspartate Aminotransferase (AST))
Alanine + Alpha-ketoglutarate -> Pyruvate + Glutamate (This is encouraged by the enzyme Alanine Aminotransferase (ALT))
What coenzyme do transaminases require? How does this affect AST and ALT?
Pyridoxyl 5’ Phosphate (PLP)
This increases ALT and AST after an MI
Which vitamin is Pyridoxyl 5’ Phosphate a derivative of??
Vitamin B6
During the metabolism of Methionine to Succinyl CoA, which is used in the TCA, what is the enzyme we need to know and what cofactor does it require?
Cystothionine B-Synthase
Requires Pyridoxal 5’ Phosphate (PLP)
What amino acid is used to form alpha-ketoglutarate in the TCA?
Glutamate, which can be formed from Glutamine
What disease occurs when there are branched chain amino acids and your urine smells sweet?
Maple Syrup Urine Disease
Acronym: I love vermont maple syrup
Isoleucine Leucine Valine Maple Syrup
What causes branched chain amino acids to be found in the urine? Essentially, what causes Maple Syrup Urine Disease?
What is the treatment?
When Branched chain alpha-keto acid dehydrogenase complex (BCKD) activity which results in branched chain ketoaciduria
Treatment is a synthetic diet that excludes branched chain amino acids like valine, leucine, and isoleucine
What causes Phenylketonuria (PKU)?
Caused by defects in the activity of phenylalanine hydroxylase (PAH), which causes phenylalanine to be converted into phenylpyruvate and phenyllactate, which causes a musty odor in the urine.
What 2 molecules are Tryptophan used as derivatives for?
Serotonin -> Melatonin
Niacin -> NAD(P)+ *Note that this requires Vitamin B6
What is Serine used as a derivative for?
Acetylcholine
What 3 molecules are Tyrosine used as derivatives for?
Dopamine -> Norepinephrine -> Epinephrine
Thyroid Hormones (T3 and T4)
Melanin
What is Glutamine used as a derivative for?
GABA
What is Arginine used as a derivative for? What is the clinical relevance to this compound?
Note that this compound is also made up of two other amino acids, what are they?
Creatine Phosphate
Its isoform is Creatine Kinase (CK), which is diagnostic for myocardial infarctions
Made up of three amino acids:
Arginine
Glycine
Methionine
What is the function of creatine phosphate?
energy storage in muscle, brain, and sperm
-quickly generates ATP and is used as our immediate energy source
What causes Albinism?
This is due to a severe lack of melanin due to the blocking of the conversion of tyrosine to melanin due to defects in the enzyme tyrosinase
How are patients with hyperthyroidism treated?
With agents that block iodination of thyroglobulin to decrease the production of T4 and T3
