Protein Metabolism and Urea Cycle

These flashcards cover key concepts related to protein metabolism, amino acids, and the urea cycle, helping to reinforce understanding for the exam.

Ketogenic amino acids

Amino acids that are converted to ketone bodies and cannot be used for gluconeogenesis, such as leucine and lysine.

Glucogenic amino acids

Amino acids that can be converted into glucose either directly or indirectly, such as phenylalanine, tryptophan, and tyrosine.

Ubiquitin-proteasome system

A regulated protein degradation mechanism that utilizes ATP to tag specific proteins for removal from the cell.

Acid hydrolases

Enzymes found in lysosomes that degrade a wide range of biomolecules without the need for ATP.

Transamination

The process of transferring an amino group from one amino acid to an alpha-keto acid, forming glutamate.

Oxidative deamination

The removal of an amino group from an amino acid, producing ammonia and an alpha-keto acid.

Urea cycle

A series of biochemical reactions in the liver that convert ammonia and carbon dioxide into urea for excretion.

Glutamate dehydrogenase

An enzyme that catalyzes the reversible interconversion of glutamate and alpha-ketoglutarate with the production of ammonia.

N-acetylglutamate (NAG)

A molecule that is essential for the activation of carbamoyl phosphate synthetase I in the urea cycle.

Cystinuria

An inherited disorder characterized by the inability to reabsorb cystine and other amino acids in the kidneys, leading to kidney stones.

Proteomics

The large-scale study of proteins, particularly their functions and structures, often to compare healthy and diseased tissue.

Peptidases

Enzymes responsible for breaking peptide bonds in proteins to facilitate digestion and absorption.

Enzyme cascade

A chain reaction of enzymatic activities where one enzyme activates another, as seen in the activation of digestive enzymes.

Aspartate

An amino acid involved in the urea cycle, serving as a nitrogen donor.

Alanine

An amino acid that plays a key role in the glucose-alanine cycle, serving as a transport molecule for nitrogen.

Peptide bond hydrolysis

The breakdown of peptide bonds in proteins facilitated by the addition of water.

Hydrolase enzymes

A class of enzymes that catalyze the hydrolysis of chemical bonds, often used in protein degradation.

Carrier proteins

Proteins that facilitate the transport of amino acids across cell membranes.

Amino group

A functional group composed of a nitrogen atom and two hydrogen atoms, vital for amino acid structure.

Peptide bond

The chemical bond formed between two amino acids during protein synthesis.