m 7Metabolism of Amino Acids and Their Derivatives

These flashcards are designed to help review key concepts related to amino acid metabolism, urea cycle, and specific metabolic disorders.

What happens to urea when supplemented with L-arginine?

Arginine helps maintain the urea cycle, producing false urea from its nitrogen.

What are the two categories of carbon backbones from amino acids?

Glucogenic and ketogenic.

What is argininosuccinate's significance in the urea cycle?

It contains two nitrogen groups that help eliminate excess nitrogen.

What amino acids are both glucogenic and ketogenic?

Some amino acids can enter both glucose production and produce ketone bodies.

What is tetrahydrofolate's role in amino acid metabolism?

It transfers carbon groups through various oxidation states.

What is alkaptonuria?

A metabolic disease where phenylalanine and tyrosine breakdown is impaired, resulting in black urine.

What is phenylketonuria?

A genetic disorder where phenylalanine cannot be converted to tyrosine, leading to a toxic buildup.

How does Roundup affect amino acid synthesis in plants?

It inhibits an enzyme necessary for producing aromatic amino acids, while GMO plants are engineered to resist it.

What are the two main pathways for synthesizing amino acids?

The glycolytic pathway and the pentose phosphate pathway.

Which amino acids are synthesized from oxaloacetate and pyruvate?

Nine amino acids, with five from oxaloacetate and four from pyruvate.

How does nitric oxide affect blood vessels?

It relaxes and dilates blood vessels.

What is the function of arginine in nitric oxide synthesis?

It serves as a substrate for nitric oxide synthase to produce NO.

What are the two main carbon backbone donors for heme production?

Glycine and succinyl CoA.

What is the significance of cyclic GMP in blood vessel dilation?

It mediates the relaxation of smooth muscle cells upon binding to guanylate cyclase.

How are melanin production and tyrosine related?

Tyrosine is a precursor necessary for producing melanin pigments.

What is the genetic cause of albinism?

A mutation in the tyrosinase gene leads to a failure in producing melanin.

What is the connection between Parkinson's disease and tyrosine hydroxylase?

Defective tyrosine hydroxylase leads to reduced dopamine production, resulting in Parkinson's symptoms.