Table of contents

Prepare for your exams

Upload your syllabus and get recommendations on what to study and when. No syllabus? Sharing your exam schedule works too.

Skip topic navigation

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart2h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

24. Metabolism and Nutrition

Essential Amino Acids

24. Metabolism and Nutrition

Essential Amino Acids: Videos & Practice Problems

Video Lessons Practice Worksheet

Topic summary

Amino acids are categorized into essential and non-essential types. Essential amino acids cannot be synthesized by the organism and must be obtained through diet, while non-essential amino acids can be produced internally. Humans require nine essential amino acids, with arginine sometimes classified as essential due to its limited synthesis. Mnemonics can aid in memorizing these essential amino acids, such as "v I p, mol" and "I let Martin Luther King trip his favorite video character." Understanding these distinctions is crucial for grasping protein synthesis and overall metabolic processes.

concept

Essential vs. Nonessential Amino Acids

Video duration:

Play a video:

Was this helpful?

Essential vs. Nonessential Amino Acids Video Summary

Amino acids are the building blocks of proteins and are categorized into two main groups: essential and non-essential amino acids. The term "essential" in biochemistry refers specifically to amino acids that cannot be synthesized by the organism itself, meaning they must be obtained through dietary sources. In contrast, non-essential amino acids can be produced by the body, allowing for flexibility in dietary intake.

For humans, there are nine essential amino acids that must be consumed: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Non-essential amino acids, such as alanine, aspartic acid, and glutamic acid, can be synthesized from other compounds within the body. Notably, arginine is often considered semi-essential because, while the body can produce it, dietary intake may still be necessary under certain conditions.

To aid in memorization of the essential amino acids, various mnemonics can be employed. One popular mnemonic is "v I p, mol," where each letter corresponds to an essential amino acid: Tryptophan (T), Threonine (T), Histidine (H), Valine (V), Isoleucine (I), Phenylalanine (P), Methionine (M), and Leucine (L). Another creative mnemonic is "I let Martin Luther King trip his favorite video character," which incorporates the initials of the essential amino acids in a memorable narrative format.

Understanding the distinction between essential and non-essential amino acids is crucial for nutrition and health, as it highlights the importance of a balanced diet that includes all necessary amino acids for optimal bodily function.

Do you want more practice?

We have more practice problems on Essential Amino Acids

Here’s what students ask on this topic:

What are essential amino acids and why are they important?

Essential amino acids are amino acids that cannot be synthesized by the human body and must be obtained through diet. They are crucial for various bodily functions, including protein synthesis, tissue repair, and nutrient absorption. The nine essential amino acids for humans are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Without these amino acids, the body cannot produce the proteins necessary for growth, repair, and maintenance of tissues, leading to potential health issues.

How can I memorize the essential amino acids effectively?

Mnemonics are a helpful tool for memorizing the essential amino acids. One popular mnemonic is 'v I p, mol,' where 'v' stands for valine, 'I' for isoleucine, 'p' for phenylalanine, 'm' for methionine, 'o' is ignored, and 'l' stands for leucine and lysine. Another mnemonic is 'I let Martin Luther King trip his favorite video character,' which stands for isoleucine, leucine, lysine, methionine, threonine, tryptophan, histidine, phenylalanine, and valine. Using these mnemonics can make it easier to recall the essential amino acids during exams or practical applications.

What is the difference between essential and non-essential amino acids?

Essential amino acids cannot be synthesized by the human body and must be obtained through diet. Non-essential amino acids, on the other hand, can be synthesized by the body from other compounds. While both types are necessary for protein synthesis and overall health, the key difference lies in their source. Essential amino acids must come from dietary intake, whereas non-essential amino acids can be produced internally, making it less critical to obtain them directly from food.

Why is arginine sometimes considered an essential amino acid?

Arginine is sometimes considered an essential amino acid because, although the human body can synthesize it, a significant portion of arginine is broken down into urea and not available for protein synthesis. This means that under certain conditions, such as periods of rapid growth, illness, or stress, the body's demand for arginine may exceed its ability to produce it, necessitating dietary intake. Therefore, arginine is often classified as conditionally essential.

What are the functions of essential amino acids in the body?

Essential amino acids play several critical roles in the body. They are the building blocks of proteins, which are necessary for tissue growth and repair. They also contribute to enzyme and hormone production, immune function, and neurotransmitter synthesis. For example, tryptophan is a precursor for serotonin, a neurotransmitter that regulates mood, while methionine is involved in methylation processes that affect DNA and protein function. Overall, essential amino acids are vital for maintaining health and supporting metabolic processes.