Chapter 25: Protein and Amino acid metabolism

________ is the continual renewal or replacement of biomolecules; for protein it is defined by the balance between protein synthesis and protein degradation.

________ is the interchange of the amino group of an amino acid and the keto group of an alpha- keto acid.

________ is the conversion of an amino acid ¬NH2 group to an alpha- keto group, with removal of NH4 +.

________ do not store nitrogen- containing compounds, and ammonia is toxic to cells.

________: conversion of an alpha- keto acid to an amino acid by reaction with NH4 +.

________ must first convert ammonia, in solution as ammonium ion, to nontoxic urea via the urea cycle.

________ atoms into compounds that can enter the citric acid cycle.

________ is the entire collection of free amino acids in the body.

The ________ is converted to glutamate, and the amino acid is converted to an alpha- keto acid.

keto acid

Building Up a Reactive Intermediate The first step of the urea cycle transfers the carbamoyl group, H2NC=O, from carbamoyl phosphate to ornithine, an amino acid not found in proteins, to give citrulline, another non-protein amino acid

one of 11 amino acids that are synthesized in the body and are therefore not necessary in the diet

an amino acid that cannot be synthesized by the body and thus must be obtained from the diet

conversion of an alpha-keto acid to an amino acid by reaction with NH4 +

the entire collection of free amino acids in the body.

Those amino acids that are converted to acetoacetyl-CoA or acetyl-CoA then enter the ketogenesis pathway and are called ketogenic amino acids.

conversion of an alpha-keto acid to an amino acid by reaction with NH4 +.