Amino Acid Metabolism and Urea Cycle

This set of flashcards covers key vocabulary and concepts related to amino acid metabolism, enzymatic reactions, and the urea cycle as discussed in the lectures.

Transamination

A biochemical process that involves the transfer of an amino group from one molecule to another, crucial for amino acid metabolism.

Glutamate Synthetase

An enzyme that catalyzes the formation of glutamate from alpha-ketoglutarate and ammonium.

Pyridoxal Phosphate (PLP)

A cofactor derived from vitamin B6, essential for transamination reactions and the metabolism of amino acids.

Urea Cycle

A series of biochemical reactions that convert ammonia to urea for excretion, primarily occurring in the liver.

Non-essential Amino Acids

Amino acids that can be synthesized by the body and do not need to be obtained from the diet.

Aminotransferase

Another term for transaminase, an enzyme that catalyzes the transfer of an amino group to form new amino acids.

Alphaketoglutarate

A key intermediate in the Krebs cycle and an important molecule in amino acid metabolism.

Glutamine

An amino acid that serves as a nitrogen donor in the synthesis of other amino acids and in the urea cycle.

Conditionally Essential Amino Acids

Amino acids that are usually non-essential but become essential under certain physiological conditions.

Carbamoyl Phosphate

A molecule formed from bicarbonate and ammonia in the urea cycle, serving as a substrate for the synthesis of citrulline.

Citrulline

An intermediate in the urea cycle formed from ornithine and carbamoyl phosphate, which is then converted to arginine.

Ornithine

An amino acid that is a key intermediate in the urea cycle and derived from arginine.

Nitrogen Fixation

The process by which certain organisms convert atmospheric nitrogen into a form usable by living organisms.

GABA (Gamma-Aminobutyric Acid)

A neurotransmitter derived from glutamate, involved in inhibitory signaling in the central nervous system.

Essential Amino Acids

Amino acids that cannot be synthesized by the body and must be obtained through diet.

Phenylalanine Hydroxylase

An enzyme that converts phenylalanine to tyrosine; defects in this enzyme lead to phenylketonuria (PKU).

Amino Group

A functional group consisting of a nitrogen atom bonded to one or more hydrogen atoms, integral to the structure of amino acids.

Beta Phosphate

A phosphate group in ATP that can transfer energy during metabolic reactions.

Serine Hydroxymethyltransferase

An enzyme that transfers a hydroxymethyl group from serine to tetrahydrofolate, producing glycine.