Amino Acids Metabolism: Tyrosine, Phenylketonuria, Albinism

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What is the metabolic role of tyrosine in the body?

Synthesis of dopamine (correct)
Synthesis of glutathione
Synthesis of insulin
Synthesis of aldosterone

Which amino acid is synthesized from phenylalanine in the liver?

Methionine
Isoleucine
Tyrosine (correct)
Leucine

Which amino acid is an essential amino acid?

Cysteine
Phenylalanine (correct)
Leucine
Tyrosine

What is the main function of melanin synthesized from tyrosine?

Protecting the skin from UV rays (B) Signup and view all the answers

What is the metabolic disorder characterized by an absence of the enzyme required for phenylalanine metabolism?

Phenylketonuria (A) Signup and view all the answers

Which of the following is a feature of albinism?

Deficiency in melanin production (A) Signup and view all the answers

What is the main cause of Hyperphenylalaninemia type 1?

Genetic deficiency of phenylalanine hydroxylase (D) Signup and view all the answers

What is the alternative pathway for oxidation of phenylalanine in Hyperphenylalaninemia type 1?

Conversion into phenylacetate, phenylpyruvate, and phenylactate (C) Signup and view all the answers

In Hyperphenylalaninemia type 1, what is the clinical manifestation related to skin color?

Light color of hair & skin (C) Signup and view all the answers

What is the diagnosis test for phenylketonuria?

Urine ferric chloride test (D) Signup and view all the answers

What is the recommended treatment for phenylketonuria in children?

Low concentrations of phenylalanine in the diet after age 6 years (B) Signup and view all the answers

What is the main cause of albinism?

Genetic deficiency of tyrosinase (C) Signup and view all the answers

What causes mental retardation and seizures in Hyperphenylalaninemia type 1?

Competitive inhibition of pyruvate transport to mitochondria by phenylpyruvate (D) Signup and view all the answers

What is the specific clinical manifestation in alkaptonuria related to urine color?

Blackish-brown urine when fresh (C) Signup and view all the answers

What is the most likely cause of ochronosis and a form of arthritis in alkaptonuria?

Build-up of homogentisate in connective tissues (A) Signup and view all the answers

What is the main biological function of protein synthesis in adults?

To replace constantly turning over proteins (D) Signup and view all the answers

Which compounds are synthesized from amino acids?

Purines and pyrimidines (C) Signup and view all the answers

What is the role of Krebs cycle in amino acid metabolism?

It provides missing elements for protein synthesis (B) Signup and view all the answers

Which enzyme is responsible for cleaving the basic amino acids from the C-terminal end of the peptide during protein digestion?

Pancreatic carboxypeptidases (B) Signup and view all the answers

What is the main function of large peptides and free amino acids in protein digestion?

Replacement of constantly turning over proteins (C) Signup and view all the answers

What is the main fate of the absorbed amino acids?

Incorporation into tissue proteins (A) Signup and view all the answers

Where does oxidative deamination of amino acids mainly occur?

Liver and kidney (A) Signup and view all the answers

What is the significance of L-glutamate dehydrogenase in oxidative deamination?

Conversion of alpha-ketoglutaric acid to glutamic acid (B) Signup and view all the answers

What is the primary metabolic fate of non-essential amino acids in the body?

Incorporation into tissue proteins (C) Signup and view all the answers

What is the main function of transamination in amino acid metabolism?

Transfer of the amino group to a suitable keto acid acceptor (B) Signup and view all the answers