How to Remember the Essential and Non-Essential Amino Acids

January 3, 2026 •

2 min read

Over 500 naturally occurring amino acids exist, but only 20 are the building blocks of proteins within the human body. Learning to tell the difference between the essential and non-essential amino acids is a fundamental skill in biochemistry and nutrition, and can be easily accomplished with simple mnemonic devices.

Quick Summary

This guide simplifies memorizing the classification of amino acids as essential, non-essential, or conditionally essential. It uses popular mnemonic phrases and a structured table to help recall and differentiate them efficiently.

Key Points

PVT TIM HALL: A key mnemonic for the nine essential amino acids.
Almost All Girls...: A mnemonic to help remember the eleven non-essential amino acids.
Conditional Category: Amino acids can be 'conditionally essential', needed from diet during stress or illness.
Multi-Method Approach: Use mnemonics alongside flashcards, writing, and quizzes for better recall.
Contextual Understanding: Learn amino acid roles and structures to reinforce memorization.

Using Mnemonics to Master Amino Acid Classification

Amino acids are the foundational units of proteins, playing a crucial role in virtually every biological process. Of the twenty standard amino acids, nine are considered essential because the human body cannot synthesize them and must obtain them through diet. The remaining eleven are non-essential, as the body can produce them endogenously. An important sub-category, known as conditionally essential amino acids, also exists; these are typically non-essential but become necessary from the diet under specific conditions of illness or stress. Memorizing these lists can be challenging, but mnemonic devices are a powerful tool for recall.

The 'PVT TIM HALL' Mnemonic for Essential Amino Acids

One of the most widely used mnemonics for remembering the essential amino acids is “PVT TIM HALL”. For the specific amino acids represented by this mnemonic, you can refer to {Link: Study.com https://study.com/academy/lesson/essential-nonessential-amino-acids-difference-roles.html}.

The 'Almost All Girls Go Crazy After Getting Taken Prom Shopping' Mnemonic

A mnemonic for the non-essential amino acids is “Almost All Girls Go Crazy After Getting Taken Prom Shopping”. Each capitalized word's first letter corresponds to a non-essential amino acid, detailed in {Link: Study.com https://study.com/academy/lesson/essential-nonessential-amino-acids-difference-roles.html}.

The Nuances: Conditionally Essential Amino Acids

Conditionally essential amino acids, are typically non-essential but become necessary from the diet during periods of high physiological stress like illness or injury.

Comparison of Amino Acid Types

For a detailed comparison of essential, non-essential, and conditionally essential amino acids, including their synthesis, dietary requirements, memory aids, and examples, see the table provided in {Link: Study.com https://study.com/academy/lesson/essential-nonessential-amino-acids-difference-roles.html}.

Memorization Techniques Beyond Mnemonics

Complementing mnemonics with other study methods can enhance recall. Techniques like flashcards, repetitive writing, and categorizing amino acids by their properties are effective. For visual memorization methods, additional resources are available on platforms like YouTube. Contextualizing by learning their metabolic roles and using quizzes or apps also aids memorization.

Conclusion: Making Amino Acid Recall Effortless

Distinguishing between essential and non-essential amino acids is crucial for biochemistry and nutrition. Mnemonics like “PVT TIM HALL” and "Almost All Girls..." offer a strong basis for memorization. Combining these with other methods such as flashcards and understanding metabolic context enhances learning, simplifying the recall of these key biological compounds.

Frequently Asked Questions

Essential amino acids must come from the diet because the body cannot make them. Non-essential amino acids can be produced by the body.

The nine essential amino acids can be recalled using the 'PVT TIM HALL' mnemonic.

Arginine is often considered conditionally essential because while the body can typically produce it, certain conditions like illness, trauma, or periods of rapid growth can increase demand beyond the body's synthesis capacity.

Yes, the mnemonic 'Almost All Girls Go Crazy After Getting Taken Prom Shopping' helps in recalling the non-essential amino acids.

Yes, it is possible to get all essential amino acids from a plant-based diet. While many plant foods are 'incomplete' proteins, consuming a variety of plant-based protein sources throughout the day ensures a complete amino acid profile.

Memorizing the classifications is fundamental. It provides a basis for understanding protein quality, dietary requirements, and the metabolic processes involving these building blocks. It’s a core component of nutrition education.

For advanced studies in biochemistry, knowing the chemical structures and properties of the side chains is necessary. However, for a basic understanding, using mnemonics and associating them with their classifications is sufficient.