histidine
Học thuậtThân thiện
Definition
- Noun:
- An essential amino acid: Histidine is one of the amino acids that the human body cannot synthesize on its own and must obtain from the diet.
- Found in proteins: It is a standard component of most proteins.
- Important for biological functions: It is crucial for the growth and repair of tissues, and plays roles in various metabolic processes.
Usage Examples
- Noun:
- Histidine is required for proper growth in infants and children.
- Many protein-rich foods, such as meat, fish, and dairy, are good sources of histidine.
- A deficiency in histidine can impair tissue repair.
Advanced Usage
- Biochemical Context: In biochemistry, histidine is noted for having an imidazole side chain, which allows it to act as a proton donor or acceptor. This makes it a common catalytic residue in enzyme active sites.
- The enzyme's activity depends on a critical histidine residue in its active site.
- Medical/Nutritional Context: It is classified as an "essential" amino acid for humans, meaning it must be consumed.
- Histidine supplementation is sometimes considered in specific clinical nutrition plans.
Variants and Related Words
- L-histidine (n): The specific, naturally occurring form (isomer) of histidine found in proteins.
- Histidinemia (n): A rare metabolic disorder characterized by elevated levels of histidine in the blood.
Synonyms
- Essential amino acid: This is its category, not a direct synonym. Other specific essential amino acids include , , and .
Related Phrases and Compounds
- Histidine decarboxylase: An enzyme that converts histidine into histamine.
- Histidine kinase: A type of enzyme involved in signal transduction in many organisms.
- Histidine-rich glycoprotein: A specific protein that contains a high proportion of histidine residues.
(Note: As 'histidine' is a specific biochemical noun, it does not have phrasal verbs or idioms associated with its common usage.)
Noun
- an essential amino acid found in proteins that is important for the growth and repair of tissue