Question

Number of essential amino acids in human is
A) 14
B) 10
C) 9
D) 6

Answer 1

Organic compounds that bind to form proteins are amino acids. The building blocks of life are amino acids and proteins. There are amino acids left after proteins are digested or broken down. To support the body, the human body uses amino acids to produce proteins: to break down food.

Complete answer:
Amino acids can also be used by the body as a source of energy.
In three groups, amino acids are classified:
-Essential amino acids
-No essential amino acids
-Conditional amino acid

Essential amino acids may not be produced by the body. As a result, they have to come from food.
The nine essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

Non essential means that our bodies produce amino acid, even if we don't get it from the food we eat.Alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine are all nonessential amino acids.

Conditional amino acids are usually not essential, except in times of disease and stress.
Conditional amino acids include: arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serum.

Animal proteins such as meat, eggs and poultry are the best sources of essential amino acids.

When you eat protein, it is broken down into amino acids, which are then used to help your body with various processes, such as muscle building and immune function regulation.

Essential Amino Acid	Function
Phenylalanine	Phenylalanine is a precursor to neurotransmitters of tyrosine, dopamine, epinephrine and norepinephrine. It plays an integral role in the structure and functioning of proteins and enzymes and in the production of other amino acids.
Valine	Valine is one of three branched-chain amino acids, meaning that it has a chain branching off to one side of its molecular structure. Valine helps stimulate muscle growth and regeneration and contributes to energy production.
Threonine	Threonine is a major component of structural proteins such as collagen and elastin, which are important components of the skin and connective tissues. It also plays a role in the metabolism of fats and immune function
tryptophan	Although often associated with causing somnolence, tryptophan has many other functions. It is needed to maintain a proper nitrogen balance and is a precursor to serotonin, a neurotransmitter that regulates your appetite, sleep and mood.
Methionine	The role of methionine in metabolism and detoxification is important. IIt is also needed for tissue growth and absorption of zinc and selenium, minerals that are vital to your health.
leucine	Like valine, leucine is a branched-chain amino acid that is critical to protein synthesis and muscle repair. It also helps to regulate blood sugar levels, stimulates wound healing and produces growth hormones.
isoleucine	Isoleucine is involved in the muscle synthesis of the last of the three branched-chain amino acids and is highly concentrated in muscle tissue. It is also essential in terms of immune function, hemoglobin output and energy regulation.
Lysine	Lysine plays a key role in protein synthesis, hormone and enzyme production and calcium absorption. It is also important for the production of energy, immune function and the production of collagen and elastin.
Histidine	Histidine is used to make histamine, a neurotransmitter that is essential for the cycles of immune response, digestion, sexual activity and sleep-wake. Maintaining the myelin sheath, a protective shield that protects the nerve cells, is important.

Thus the correct answer is option ‘C’.

Note: Although amino acids are most recognized for their role in muscle development and repair, so much more depends on the body.
That's why essential amino acid deficiencies can negatively affect your entire body, including your nervous, reproductive, immune and digestive systems.