The Book of Threes

The Twenty Amino Acids

Essential amino acids
Essential amino acids cannot be made by the body. As a result, they must come from food.
The nine essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Nonessential amino acids
"Nonessential" means that our bodies produce an amino acid, even if we don't get it from the food we eat.
They include: alanine, asparagine, aspartic acid, and glutamic acid.
Conditional amino acids
Conditional amino acids are usually not essential, except in times of illness and stress.
They include: arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine.
You do not need to eat essential and nonessential amino acids at every meal, but getting a balance of them over the whole day is important.

The twenty amino acids (that make up proteins) each have assigned to them a three-letter code.

alanine – ala –  
arginine – arg –  
asparagine – asn –  
aspartic acid – asp –  
cysteine – cys – 
glutamine – gln – 
glutamic acid – glu –  
glycine – gly – 
histidine – his – 
isoleucine – ile – 
leucine – leu – 
lysine – lys – 
methionine – met – 
phenylalanine – phe –  
proline – pro – 
serine – ser – 
threonine – thr – 
tryptophan – trp – 
tyrosine – tyr – 
valine – val – 
Sometimes it is not possible two differentiate two closely related amino acids, therefore we have the special cases:
asparagine/aspartic acid – asx – 
glutamine/glutamic acid – glx – 
Here is list where amino acids are grouped according to the characteristics of the side chains:
Aliphatic – alanine, glycine, isoleucine, leucine, proline, valine 
Aromatic – phenylalanine, tryptophan, tyrosine 
Acidic – aspartic acid, glutamic acid 
Basic – arginine, histidine, lysine 
Hydroxylic – serine, threonine 
Sulphur-containing – cysteine, methionine 
Amidic (containing amide group) – asparagine, glutamine 


Author: admin

Three is the Magic Number

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