Question

In general, what categories of amino acids are essential in humans and which are nonessential?

Short answer

Essential amino acids must be obtained from diet and include nine specific amino acids. Nonessential amino acids can be synthesized by the body.

Step-by-step solution

Understand the Concept of Essential Amino Acids

Essential amino acids are those that cannot be synthesized by the human body and must be obtained from the diet.

List the Essential Amino Acids

The essential amino acids in humans are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Understand the Concept of Nonessential Amino Acids

Nonessential amino acids are those that can be synthesized by the human body and do not need to be obtained from the diet.

List the Nonessential Amino Acids

The nonessential amino acids in humans include: alanine, asparagine, aspartic acid, glutamic acid, and serine.

Recognize Conditional Amino Acids

Some amino acids are classified as conditional, meaning they are normally nonessential but become essential under certain conditions such as illness or stress. These include arginine, cysteine, glutamine, tyrosine, glycine, proline, and serine.

Key concepts

Essential Amino Acids

Essential amino acids are vital to the human body. However, unlike some other amino acids, our bodies cannot create them. This means we must get them from the foods we eat. In humans, there are nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
These amino acids play crucial roles in growth, repair, and maintenance of body tissues. Without them, our bodies wouldn't function properly. It's important to include a variety of protein sources in your diet to ensure you're getting all the essential amino acids your body needs.

Nonessential Amino Acids

Conditional amino acids are a special group. They are generally considered nonessential because the body can produce them. However, under certain conditions like illness, stress, or injury, they become essential because the body's demand for them increases.
Examples of conditional amino acids are arginine, cysteine, glutamine, tyrosine, glycine, proline, and serine. During times of physical stress or illness, it's crucial to ensure adequate intake or supplementation of these amino acids. They help the body cope and recover efficiently.