Which of the following statements is true of essential amino acids?
Their recycling is different from that of nonessential amino acids.
These amino acids are produced in excess within the body.
These amino acids do not contain a side chain attached to the backbone.
These amino acids cannot be made by the body
The Correct Answer and Explanation is :
The correct answer is:
“These amino acids cannot be made by the body.”
Explanation:
Amino acids are the building blocks of proteins and are classified into essential and nonessential amino acids.
Essential Amino Acids
Essential amino acids are those that the body cannot synthesize on its own in sufficient amounts. Therefore, they must be obtained from the diet through protein-rich foods such as meat, dairy, eggs, and plant-based sources like beans, nuts, and quinoa. There are nine essential amino acids in humans:
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
These amino acids play critical roles in muscle repair, enzyme production, neurotransmitter synthesis, and immune function.
Why Are the Other Statements Incorrect?
- “Their recycling is different from that of nonessential amino acids.”
- Both essential and nonessential amino acids undergo similar metabolic pathways for recycling. The main difference is that essential amino acids must come from the diet.
- “These amino acids are produced in excess within the body.”
- The body does not produce essential amino acids in excess or even in small amounts.
- “These amino acids do not contain a side chain attached to the backbone.”
- All amino acids, including essential ones, have side chains (R-groups) that determine their unique properties.
Thus, essential amino acids are vital nutrients that must be obtained through diet for proper growth, muscle maintenance, and overall health.