Definition

Noun: An essential amino acid is an amino acid that an organism requires for proper physiological function but cannot synthesize on its own in sufficient quantities. Therefore, it must be obtained from the diet.

Usage

The term is used in the fields of nutrition, biochemistry, and physiology to describe a specific class of nutrients critical for protein synthesis and various metabolic processes. * A balanced diet must include all essential amino acids. * Lysine is an essential amino acid for humans. * The researcher studied which essential amino acids were lacking in the plant-based protein.

Advanced Usage

• Conditionally essential amino acids: Under certain physiological conditions (e.g., illness, prematurity), some amino acids that are normally non-essential become essential and must be sourced from food.
• The concept is species-specific; an amino acid essential for one animal (e.g., taurine for cats) may not be for another.

Variants and Related Words

• Amino acid (n): The broader class of organic compounds that are the building blocks of proteins. Essential amino acids are a subset of these.
• Non-essential amino acid (n): An amino acid that an organism can synthesize internally and does not need to obtain from food.
• Indispensable amino acid (n): A synonym for essential amino acid, often used in scientific literature.

Synonyms

• Indispensable amino acid

Different Meanings

The term essential amino acid has a precise scientific meaning and is not commonly used with different meanings. However, in general language, the word "essential" alone can mean "absolutely necessary," which aligns with the core concept of the compound term.

Related Phrases/Idioms

• Complete protein: A food source that contains all nine essential amino acids in adequate proportions for humans (e.g., meat, eggs, quinoa, soy).
• Limiting amino acid: The essential amino acid that is present in the smallest amount relative to requirement in a food protein, thus limiting the body's ability to use the other amino acids for protein synthesis.

Noun

1. an amino acid that is required by animals but that they cannot synthesize; must be supplied in the diet