gen-define-essential-amino-acids-and-give-one-short-worked-examp-4ab6

Define essential amino acids and give one short worked example.

# Essential Amino Acids **Definition:** Essential amino acids are amino acids that cannot be synthesized by the human body (or synthesized in insufficient amounts) and must be obtained through the diet. ## Key Points: - There are **9 essential amino acids** for adults: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine - The body lacks the metabolic pathways to produce these amino acids - Deficiency can lead to protein malnutrition and various health problems --- ## Worked Example: Lysine Deficiency **Scenario:** A person follows a diet consisting primarily of corn (maize) as their protein source. **Problem:** Corn is deficient in lysine (an essential amino acid). **Consequence:** - Without adequate lysine intake, the body cannot: - Synthesize complete proteins effectively - Maintain proper collagen formation - Support normal growth and tissue repair **Solution:** Complement corn with **legumes** (beans, lentils), which are rich in lysine. This is why traditional diets often pair grains with legumes (e.g., rice and beans, corn tortillas and black beans) to achieve a complete amino acid profile. This demonstrates the principle of **protein complementation** - combining different plant proteins to obtain all essential amino acids.