Amino acid

Amino acid (amino acid) contains: amino and carboxyl A class organic compound The generic term. Biological function Macromolecule Protein The basic unit, constitute the basic material of animal nutrition required protein. Contains basic amino and Carboxylic acid The organic compounds. Even in the alpha amino carbon for Alpha amino acid . Amino acids are alpha amino acid.
Amino acid

Amino acid General structure

 The structure of amino acid formula The structure of amino acid formula
Refers to the amino acid containing amino group carboxylic acid . A variety of proteins in living organisms is composed of 20 basic amino acids. except glycine Are L - alpha - amino acid proline (which is a L alpha Imino acid ), its general structure (as shown in figure R based variable Group ):
Except glycine, alpha amino acid carbon atoms of other proteins are asymmetric carbon atoms (i.e. four and alpha carbon atom bonded Substituent Different), so the amino acids can be Stereoisomer That is, can have different configurations (type D and L type two configuration).

Amino acid Nature

Colorless crystal, high melting point, generally more than 200 DEG C. Different amino acid taste different, some tasteless, some sweet, some bitter, monosodium glutamate flavor, is the main component of msg. All kinds of amino acid solubility in water vary greatly, and can dissolve in dilute acid or alkali, but not soluble in organic solvent . Usually alcohol can amino acid from its solution precipitation.

Amino acid UV absorption properties

One of the most important optical properties of amino acids is of light absorption.
 Amino acid Amino acid
20 kinds of Pr - AA in the visible light region, no light absorption in the far ultraviolet region (<220nm) has light absorption in the ultraviolet region (near ultraviolet) (220nm ~ 300nm) only three AA light absorption ability, three of these amino acids Phenylalanine , Tyrosine , Tryptophan R, because of their containing benzene Conjugated double bond System. AA styrene acrylic maximum absorption at 259nm, 278nm, AA in AA cheese color in 279nm, proteins generally contain these three AA residues, so the maximum absorption wavelength at about 280nm, so it can use the spectrophotometric determination of the protein content is very convenient. Determination of protein content by spectrophotometry is based on Longbow Bill's law . The 280nm protein solution light absorption value is proportional to its concentration.

Amino acid acid-base properties

1, amphoteric dissociation With the isoelectric point
The amino acids in the aqueous solution Or in the crystal are basically Facultative ion or Ion dipole The form of existence. The amphoteric ion is in the same molecule with amino acid release proton NH Three Valine ion and proton COO can accept Negative ion, amino acid is therefore Amphoteric electrolyte .
The isoelectric points of amino acids: amino acids charged depends on the pH value, can make the amino acids with a positive or negative charge change pH, also can make it in an equal number of positive and negative charges, i.e. Net charge Zero Amphoteric ion State. The amino acids with positive and negative charge is equal to the number of the net charge is zero solution pH value is called the AA
2, Dissociation constant
Type K dissociation One And K Two 'representing the alpha carbon atom on -COOH and -NH Three The performance of the dissociation constant. In biochemistry, the dissociation constant is under specific conditions (a certain concentration and ionic strength Determination of). The calculation of isoelectric point can be determined by the molecular dissociation group on the apparent dissociation constant.
The list of amino acid dissociation constant:

  
Abbreviation Chinese translation Branched chain molecular weight Isoelectric point The carboxyl group dissociation constant Amino acid dissociation constant Pkr (R) R base
Gly G glycine Hydrophilic Seventy-five point zero seven Six point zero six Two point three five Nine point seven eight   -H
Ala A alanine Hydrophobic Eighty-nine point zero nine Six point one one Two point three five Nine point eight seven   -CH
Val V valine Hydrophobic One hundred and seventeen point one five Six Two point three nine Nine point seven four
  
-CH- (CH)
Leu L leucine Hydrophobic One hundred and thirty-one point one seven Six point zero one Two point three three Nine point seven four
  
-CH -CH (CH)
Ile I isoleucine Hydrophobic One hundred and thirty-one point one seven Six point zero five Two point three two Nine point seven six   -CH (CH -CH -CH)
Phe F Phenylalanine Hydrophobic One hundred and sixty-five point one nine Five point four nine Two point two zero Nine point three one   -CH -C H
Trp W Tryptophan Hydrophobic Two hundred and four point two three Five point eight nine Two point four six Nine point four one   -C NH
Tyr Y Tyrosine Hydrophobic One hundred and eighty-one point one nine Five point six four Two point two zero Nine point two one Ten point four six -CH -C H -OH
Asp D Aspartic acid Acidic One hundred and thirty-three point one zero Two point eight five One point nine nine Nine point nine zero Three point nine zero -CH -COOH
Asn N Asparagine Hydrophilic One hundred and thirty-two point one two Five point four one Two point one four Eight point seven two   -CH -CONH
Glu E glutamate Acidic One hundred and forty-seven point one three Three point one five Two point one zero Nine point four seven Four point zero seven - (CH) -COOH
Lys K Lysine alkalinity One hundred and forty-six point one nine Nine point six zero Two point one six Nine point zero six Ten point five four - (CH) -NH
Gln Q glutamine Hydrophilic One hundred and forty-six point one five Five point six five Two point one seven Nine point one three   - (CH) -CONH
Met M methionine Hydrophobic One hundred and forty-nine point two one Five point seven four Two point one three Nine point two eight   - (CH) -S-CH
Ser S serine Hydrophilic One hundred and five point zero nine Five point six eight Two point one nine Nine point two one   -CH -OH
Thr T threonine Hydrophilic One hundred and nineteen point one two Five point six zero Two point zero nine Nine point one zero   -CH (CH) -OH
Cys C cysteine Hydrophilic One hundred and twenty-one point one six Five Point Zero Five One point nine two Ten point seven zero Eight point three seven -CH -SH
Pro P proline Hydrophobic One hundred and fifteen point one three Six point three zero One point nine five Ten point six four   -C H
His H histidine alkalinity One hundred and fifty-five point one six Seven point six zero One point eight zero Nine point three three Six point zero four  
Arg R Arginine alkalinity One hundred and seventy-four point two zero Ten point seven six One point eight two Eight point nine nine Twelve point four eight  

3, multi amino ( Basic amino acid Multicarboxyl (and) Acidic amino acids The dissociation amino acid)
Dissociation principles: the first dissociation of alpha -COOH, followed by other -COOH; then the dissociation of alpha -NH Then, the other -NH Three . In a word group Dissociation degree The -C group is greater than the amino, alpha -C alpha is larger than the same group of dissociation degree. The calculation of isoelectric point: first write dissociation equation, Amphoteric ion The log view of the left and right ends of the dissociation constant of the The arithmetic mean value . General pI value is equal to two pK value and half similar. Such as aspartic acid lysine.
4, the amino acid pH Titration curve
In case of glycine: Mole Glycine in water solution, the solution pH was 5.97, respectively, with the standard NaOH and HCl The pH value of the solution for titration. The ordinate Join HCl and NaOH. The number of moles As a horizontal coordinate mapping, by titration curve. A very important feature of this curve is the two inflection point in pH=2.34 and pH=9.60, respectively, pK One And pK Two . Rule: pH One ', [R]>[R +]>[R]; pH>pK Two 'when [R]>[R +]>[R ]; pH=pI, the net charge is zero, [R]=[R ]; pHpI, the net charge is "-".

Amino acid classification

20 kinds of protein Amino acid In the structure of the difference depends on the side chain Group R different. Usually according to the chemical structure or properties of R groups of 20 kinds of amino acids are classified
According to the polarity of the side chain groups
Non polar amino acids (hydrophobic amino acid) 8
Alanine (Ala)
Valine (Val)
Leucine (Leu)
Isoleucine (Ile)
Proline (Pro)
Phenylalanine (Phe)
Tryptophan (Trp)
Methionine (Met)
Polar amino acid (hydrophilic amino acid):
Polar uncharged: 7
Glycine (Gly)
Serine (Ser)
Threonine (Thr)
Cysteine (Cys)
Tyrosine (Tyr)
Asparagine (Asn)
Glutamine (Gln)
Polar zone Positively charged amino acids ( Basic amino acid 3) lysine (Lys) arginine (Arg) histidine (His)
The polarity of negatively charged amino acids ( Acidic amino acids 2) aspartic acid (Asp) glutamate (Glu)
 Amino acid Amino acid
According to the chemical structure
Aliphatic amino acid:
C, valine, isoleucine, bright, egg, asparagus, valley, Lai, fine, Gansu, silk, Jiangsu, cysteine, asparagine, glutamine
Aromatic amino acid Phenylalanine and tyrosine.
Heterocyclic amino acid, histidine, tryptophan
Heterocyclic imino acid: proline
From the point of view of nutrition
1, essential amino acid (essential amino acid): refers to the human body (or other vertebrates) cannot synthesize cannot meet the needs of the body, required by food protein supply, these amino acids are called essential amino acids. Adult requirement about essential amino acid protein requirement of 20% ~ 37%. There are 8 kinds of the effects are:
Lysine: promote brain development, is a component of the liver and bile, can promote Fat metabolism The pineal gland, regulating, breast, ovarian and corpus luteum, prevent cell degeneration;
Tryptophan: promote gastric and pancreatic juice;
In the loss of phenylalanine: eliminate kidney and bladder function;
Methionine (methionine): part of hemoglobin, serum and tissue, promote the function of spleen and pancreas and lymph;
Change of some amino acids threonine: balance function;
Isoleucine: in the spleen and thymus and pituitary regulation and metabolism; pituitary gland is the headquarters of the effect on the thyroid gland and gonads;
Balance: leucine isoleucine;
Val: the role of the corpus luteum, breast and ovarian.
2, Semi essential amino acids and The conditions of essential amino acids :
Arginine and arginine Deoxycholic acid Composite preparations made is an effective drug (Ming Xenophon) attending syphilis, viral jaundice disease.
Histidine can be used as: Biochemical reagent And the pharmacy, but also can be used for the treatment of heart disease, anemia, rheumatoid arthritis and other drugs.
The human body is able to synthesize arginine and histidine, but usually can not meet the normal needs, therefore, also known as Semi essential amino acids Or conditionally essential amino acid, in the children's growth period of these two kinds of essential amino acids is. The body of essential amino acid The required amount decreased with increasing age, was significantly lower than the adult baby. (in recent years, a lot of information and textbooks will be included in the adult essential amino acids histidine)
3, Non essential amino acids (nonessentialamino acid): refers to a person (or other vertebrates) by their precursor for the synthesis of simple, does not need the amino acid obtained from food. For example, such as glycine and alanine amino acid.

Amino acid Abbreviations and symbols

Name Three symbols Word symbols
Ala
A
Arg
R
Aspartic acid
Asp
D
Cys
C
Gln
Q
glutamate
Glu
E
His
H
isoleucine
Ile
I
Gly
G

alanine
Ala
A
Arginine
Arg
R
Aspartic acid
Asp
D
cysteine
Cys
C
glutamine
Gln
Q
glutamate
Glu
E
histidine
His
H
isoleucine
Ile
I
glycine
Gly
G
Name Three symbols Word symbols
Asn
N
Leu
L
Lysine
Lys
K
Met
M
Phenylalanine
Phe
F
proline
Pro
P
serine
Ser
S
threonine
Thr
T
Tryptophan
Trp
W

Asparagine
Asn
N
leucine
Leu
L
Lysine
Lys
K
methionine
Met
M
Phenylalanine
Phe
F
proline
Pro
P
serine
Ser
S
threonine
Thr
T
Tryptophan
Trp
W
Name Three symbols Word symbols
Tyr
Y
valine
Val
V

Tyrosine
Tyr
Y
valine
Val
V

Amino acid Synthesis

Most of the amino acid composition of the protein is Yiaimudeng - Meyerhof (Embden Meyerhof) and citric acid cycle pathway intermediates for carbon chain backbone biosynthesis The. The exception is the aromatic amino acid, histidine, phosphate intermediate erythrose -4- biosynthesis and pentose phosphate of the former, the latter is synthesized by ATP and the phosphoribosyl pyrophosphate. Microorganisms and plants in vivo synthesis of all amino acids, animal is a part of the amino acid can not be synthesized in the body ( essential amino acid ). The essential amino acids by intermediate carbohydrate metabolism, by a multi-step reaction (step 6 above) and non essential amino acid biosynthesis, the synthesis of the enzymes required for the synthesis of about 14 species, and essential amino acids need more, there are about 60 kinds of enzymes. In addition to the biosynthesis of amino acids as raw materials for the synthesis of the protein, but also for the synthesis of alkaloids, lignin etc.. On the other hand, the amino acids in the organism due to the formation of amino transfer or oxidation. Keto acid By the decomposition, or because of Decarboxylation After being decomposed into amine.

Amino acid The role of amino acids

As the first body of nutrient elements in the protein, its role in food nutrition is obviously, but it is in the body and can not be directly used, but by small molecules into amino acids after use. Is it in the human gastrointestinal tract is not directly absorbed by the body, but in the gastrointestinal tract through a variety of digestive enzymes, the polymer Protein decomposition Low molecular peptides or amino acids, absorbed in the small intestine along the hepatic portal vein into the liver. A part of the amino acid decomposition or protein synthesis in the liver; the other part of the amino acid to with the blood to the various tissues and organs, the selection of various specific tissue protein synthesis. Under normal circumstances, the amino acid into the blood and the output speed is nearly equal, normal amino acid content in the blood is so constant. Such as Amino nitrogen Plan, content per ml of plasma was 4 ~ 6 mg per 100 ml of blood content was 6.5 ~ 9.6 mg. After a meal of protein, amino acid absorption, amino acid level in the blood is temporarily increased after 6 to 7 hours, the content returned to normal. In vivo Amino acid metabolism In dynamic equilibrium, with the balance of amino acids in the blood of hub, liver is an important regulator of blood amino acids. Therefore, food protein after digestion after amino acid is absorbed by the human body, these antibodies by amino acid and its protein synthesis. The protein body is actually needed for amino acids.

Amino acid Nitrogen balance

When the quality and quantity of protein daily dietary intake is appropriate, the amount of nitrogen from nitrogen is equal to the amount of feces, urine and skin discharge, called total nitrogen balance. Is actually between protein and amino acid synthesis and decomposition of the balance between. Normal daily feed protein should be kept in a certain range, suddenly increase or decrease food intake, body weight and metabolism can regulate the protein to maintain nitrogen balance. Ingestion of excess protein, beyond the body will adjust ability, balance mechanism is destroyed. Don't eat protein, tissue protein decomposition still persists, negative nitrogen balance, if not to take timely corrective measures, will eventually lead to the death of antibody.

Amino acid Turn into fat

Amino acid Catabolism The a keto acid, with different characteristics, sugar or fat. The metabolic pathway Metabolism. A acid re synthesis of new amino acids, or converted into sugar or fat, or into the three carboxy cycle Oxidative decomposition CO Two And H Two O, and release energy.

Amino acid Have one carbon unit

Some amino acids Catabolism Which contains a process carbon atom The Group , including methyl, methylene And a vinyl, A alkyne Radical, radical and cresol formamino etc..
Onecarbonunit It has two characteristics: 1 not to in vivo free There are 2 forms to tetrahydrofolate as the carrier. Can the amino acid of one carbon unit: serine, tryptophan, histidine, glycine. In addition to methionine via S- (methionine) S-adenosylmethionine (SAM) provides "active methyl" (one carbon unit), so the methionine can also generate one carbon unit. The main physiological function of one carbon unit is as raw materials for the synthesis of purines and pyrimidines, amino acids and nucleotide Link.

Amino acid Participate in the composition of enzymes

Participate in the composition of enzymes, hormones, vitamins. The chemical nature of the enzyme is protein (amino acid molecules, such as amylase), Pepsin , Cholinesterase , carbonic anhydrase And transaminase. Nitrogen containing hormone ingredients are proteins or their derivatives, such as growth hormone, Thyroid stimulating hormone , adrenaline Insulin, promoting intestinal hormone, etc.. Some vitamins are made of amino acids and proteins exist or change. The role of enzymes, hormones, vitamins are important in regulating physiological function and metabolism process plays a catalytic.

Amino acid Amino acid requirement

Adult requirement about essential amino acid protein requirement of 20% ~ 37%.

Amino acid The basic reaction detection

1, Three indene ketone reaction (ninhydrin reaction)
Note the color reagent
Three indene ketone ( weak acid The environment (heating) purple proline, hydroxyproline (yellow) test of alpha amino)
2, Sakaguchi reaction (Sakaguchi reaction) Alpha naphthol Basic + time Sodium bromate gules
(inspection Guanidine Arginine is this reaction)
3, miloon reaction (also called Milunshi reaction )
HgNO Three +HNO Three Hot red (test phenolic tyrosine have this reaction, without heating is white)
4, Folin-Ciocalteau (reaction Phenol reagent )
Phosphotungstic acid Phosphorus acid (phenol blue clamp test tyrosine have this reaction)
5, yellow protein reaction
Concentrated nitric acid Boiling yellow (test benzene ring of tyrosine, phenylalanine and tryptophan have this reaction)
6, Hopkin-Cole (reaction Glyoxylic acid reaction )
join Glyoxylic acid After mixing the added concentrated sulfuric acid Produce purple ring acetaldehyde and concentrated sulfuric acid at the contact surface (test Indolyl Tryptophan had this reaction)
7, Ehrlich reaction
P- two dimethylamino Benzaldehyde + Hydrochloric acid Blue (tryptophan indole test this reaction)
8, nitroprusside test
Na Two (NO) Fe (CN) Two *2H Two O Dilute ammonia Red (test the cysteine thiol reaction)
9, Sulliwan reaction
1, 2 Naphthaquinone 4, +Na sodium sulfonate Two SO Three Red (test the cysteine thiol reaction)
10, Folin reaction
1, 2, 4 naphthoquinone sulfonate in alkaline solution of deep red (alpha amino acid test)
The peptide bond (peptide bond): a carboxyl group of the amino acid with another amino acid condensation Remove the water molecules form. amide Key.
peptide (peptide): two or more than two amino groups by peptide bonds Covalent The connection form of polymer. Is a compound amino acid linked by peptide bonds, incomplete protein hydrolysis The product is a peptide. According to the number of the amino acid composition of the peptide was 2, 3 and 4 different respectively Two peptide Four, three peptide and peptide, containing 10 amino acids known as following Oligopeptide (oligopeptide), composed of more than 10 known amino acids polypeptide (polypeptide), they are referred to as peptide. Peptide The amino acid is not free amino acid molecules, because its amino and carboxyl groups in the formation of peptide bond are binding off, so the amino acid polypeptide and protein molecules are called in Amino acid residues (amino acid residue).
Open chain peptide and polypeptide Cyclic peptide . In the human body is mainly open chain peptide. Open chain peptide has a free amino terminus and a free carboxyl terminus, respectively retained free alpha alpha amino and carboxyl groups, so it is also called The polypeptide chain The N terminal (amino terminus) and C (Suo Jiduan), writing will generally be written on the left end of the N molecule, and (H) said that this was the start of the amino acid residues in the peptides were numbered, and will end at the molecular chains of C written on the right, and (OH) to express. The composition and sequence of amino acid peptide was determined from about 200 thousand kinds of polypeptide and protein molecules in, many of which are closely related to the relationship between polypeptide medicine, has important physiological functions or pharmacological action.
The polypeptide is widely distributed and important physiological functions in vivo. among glutathione stay Red blood cell Rich in content, can protect the structure of cell membrane and the intracellular enzyme activity, protein in reduction state The function of. And in all kinds of polypeptide, glutathione unusual structure, molecular glutamate is the gamma carboxyl and cysteine alpha amino dehydration synthesis Generation of peptide bonds in the cell, and it can be reversible Redox reaction Therefore, there are also two kinds of reduced and oxidized glutathione.
Some powerful biological activity The peptides being discovered and identified, most of them have important physiological functions or pharmacological effects, and as some of the "brain peptide" and the body of learning and memory, sleep, appetite and behavior are closely related, which increases the awareness of the importance of the peptide, polypeptide has become one of the research fields in biochemistry striking.
The difference between peptide and protein, is a polypeptide protein amino acid residues is less, generally less than 50, while the protein is mostly composed of more than 100 amino acid residues, but between them the numbers are not strictly The dividing line In addition, the molecular weight, that generally no rigorous and polypeptide space structure is relatively stable, the space structure variable has plasticity, and the protein molecules with spatial structure is relatively tight, relatively stable, which is the basis of proteins play a physiological function, so the general will Insulin Classified as protein. But some books are not strictly called insulin peptides, because of its small molecular weight. But the peptide and protein amino acids are poly condensation, and the product is not completely hydrolyzed protein polypeptide. 8, cyclohexanone, its preparation and its synthesis
Amino acids and amino acid composition of two peptides and three peptide absorption and Monosaccharide Similar to active transport, and are the same Na Coupled transport. When the peptide into the intestinal mucosal epithelial cells, was immediately found in cells Peptidase Hydrolysis to amino acid. Therefore, absorbed into the venous blood in almost all amino acids.

Amino acid In the medical treatment

Amino acids in medicine mainly used for the preparation of Compound amino acid Infusion, also used as therapeutic drugs and for the synthesis of peptide drugs. As a drug and 100 kinds of amino acids, including 20 kinds of amino acids of protein and non protein amino acid composition of 100 kinds of.
Compound preparation composed of various amino acids occupies a very important position in modern parenteral nutrition and dietary factor "therapy, to maintain nutrition in critically ill patients, save the lives of patients play a positive role, has become one of the indispensable varieties of medicine in modern medical.
Glutamic acid, arginine, Aspartic acid , Cystine L - DOPA amino acid alone in treatment of some diseases, mainly used for the treatment of liver diseases, gastrointestinal diseases, encephalopathy, Cardiovascular disease Respiratory disease and for increasing muscle activity, pediatric nutrition and detoxification. in addition Amino acid derivatives The hope in the treatment of cancer.

Amino acid The activities of human life

Amino acids are the organism protein and is also related to life activities of the most basic material, is the basic unit of protein molecules in the organism, has a close relationship with the biological activity of life. It has special physiological function in antibody, is one of the nutrients necessary for organisms.
One of the basic material of human body
As the basic unit of amino acid protein, is undoubtedly constitute one of the most basic material in human body.

Amino acid material basis

The origin of life, existence and extinction, a protein involved in, as Engels Said: "the protein is the material basis of life, life is a form of protein exists." If the human body is the lack of protein, light physical decline, growth retardation, resistance weakened, anemia, fatigue, or a edema And even life-threatening. Once out of the protein, life will cease to exist, so it is called as "the life of the carrier protein". It can be said that it is the first element of life.
The basic unit of protein amino acid. If the body lacks any kind of essential amino acids, can lead to physiological dysfunction, affect metabolism of normal, finally lead to disease. Similarly, if the lack of some non essential amino acids in the human body, the body will produce Metabolic disorders . Arginine and Citrulline Is very important for the formation of urea; Cystine Insufficient intake will cause less insulin, blood sugar Rise。 And as demand after trauma, cysteine and arginine increased, such as the lack of sufficient heat energy, even if still not successful protein synthesis. In short, the amino acid in the human body through the metabolism can play the following effects: the synthesis of tissue protein; 2 into acid, hormone, antibody, creatine Such as ammonia containing substances; the change of carbohydrate and fat; the oxidized into carbon dioxide and water and urea, produce energy.

Amino acid Amino acid food

The content of amino acid rich foods like fish, squid, octopus, eel, loach, sea cucumber Cuttlefish, Silkworm Chicken, Frozen bean curd , seaweed, etc.. In addition, like beans, beans, peanuts, almonds or banana containing amino acid is more
beef Egg, soybean , Tremella And fresh fruits and vegetables
Animal offal, lean meat, fish, milk, Yam Lotus root, etc. * Corn A serious lack of lysine

Amino acid The metabolic pathway

The specific pathways involved in the metabolism of amino acids are the following:
Mainly in the liver: including the following process:
The first step: oxidative deamination, dehydrogenation, formation of imine; second step hydrolysis. The generated H Two O Two Toxic, in Catalase Under the catalysis of H generation Two O and O Two The lifting of the cell toxicity.
wrong Oxidative deamination The reductive deamination (strictly anaerobic conditions); the hydrolytic deamination; the dehydration deamination; the removal of thiol deamination; the redox deamination, two amino acids each redox reaction, generate organic acid Keto acid, ammonia, and deamidation.
Transamination. Transamination is an important way for deamination of amino acids, except Gly, Lys, Thr and Pro, most of the amino acids are involved in transamination. Occurrence of transamination between alpha amino acid and alpha keto acid, the result is the original amino acids corresponding Keto acid The original, and generate the corresponding keto amino acid.
Combined deamination: by transamination can eventually lost amino by oxidative deamination can not meet the needs of the body of deamination. With the help of the body Transdeamination You can quickly deaminate: 1. Glutamate dehydrogenase As the center Combined deamination Effect。 Amino acid alpha amino to Alpha ketoglutaric acid On the formation of the corresponding - keto acid and Glu, and then in the L-Glu The removal of ammonia Enzyme catalysis The next generation, deamination of alpha ketoglutarate, and the release of ammonia. 2, by Purine nucleotide cycle The combined deamination by. skeletal muscle Heart, liver, brain, is a purine nucleotide cycle mode.
Organisms can be most amino acid decarboxylation, generate the corresponding primary amine. Amino acid decarboxylase Highly specific, each amino acid has a decarboxylase, coenzyme Are all Pyridoxal phosphate . Amino acid Decarboxylation reaction Widely existing in animals, plants and microorganisms, some products have important physiological functions, such as brain tissue L-Glu decarboxylation of r- amino butyric acid, is an important neurotransmitter. His decarboxylation histamine (also called Histamine ), lower blood pressure. Tyr decarboxylation Tyrosamine A rise in blood pressure. But most of animal toxic amine, amine oxidase in vivo can be oxidized to aldehyde, amine and ammonia.
Therefore, the presence of amino acids in the human body, not only provides important raw material for the synthesis of protein, but also promotes the growth of normal metabolism, provides the material basis for the maintenance of life. If the body lacks or reduce one, the human body will have normal metabolic disorder, and even lead to the occurrence of various diseases or termination of life activities.

Amino acid The corresponding codon table

Codon (codonm), RNA In each of the three adjacent molecules nucleotide A group in protein synthesis, represent a kind of amino acid. Scientists have found that the messenger RNA can determine the protein molecules of the amino acid composition and sequence in cells. That is to say, the four nucleotides in the RNA molecule (messenger Base ) sequence can determine 20 kinds of amino acids in the protein molecule. The corresponding relation between base and the number of amino acids, the number is? In order to determine this relationship, the researchers added all the material a 120 BP RNA messenger molecules and the protein required in the tube, resulting in the production of a polypeptide containing 40 amino acid molecules. Therefore, the three messenger RNA molecules on the base to decide an amino acid.
Codon table:
The first letter
Second letters
Third letters
U
C
A
G
U
Phenylalanine
serine
Tyrosine
cysteine
U
U
Phenylalanine
serine
Tyrosine
cysteine
C
U
leucine
serine
termination
termination
A
U
leucine
serine
termination
Tryptophan
G
C
leucine
proline
histidine
Arginine
U
C
leucine
proline
histidine
Arginine
C
C
leucine
proline
glutamine
Arginine
A
C
leucine
proline
glutamine
Arginine
G
A
isoleucine
threonine
Asparagine
serine
U
A
isoleucine
threonine
Asparagine
serine
C
A
isoleucine
threonine
Lysine
Arginine
A
A
Methionine (starting)
threonine
Lysine
Arginine
G
G
valine
alanine
Aspartic acid
glycine
U
G
valine
alanine
Aspartic acid
glycine
C
G
valine
alanine
glutamate
glycine
A
G
Val (start)
alanine
glutamate
glycine
G

The first letter
Second letters
Third letters
U
C
A
G
U
Phenylalanine
serine
Tyrosine
cysteine
U
U
Phenylalanine
serine
Tyrosine
cysteine
C
U
leucine
serine
termination
termination
A
U
leucine
serine
termination
Tryptophan
G
C
leucine
proline
histidine
Arginine
U
C
leucine
proline
histidine
Arginine
C
C
leucine
proline
glutamine
Arginine
A
C
leucine
proline
glutamine
Arginine
G
A
isoleucine
threonine
Asparagine
serine
U
A
isoleucine
threonine
Asparagine
serine
C
A
isoleucine
threonine
Lysine
Arginine
A
A
Methionine (starting)
threonine
Lysine
Arginine
G
G
valine
alanine
Aspartic acid
glycine
U
G
valine
alanine
Aspartic acid
glycine
C
G
valine
alanine
glutamate
glycine
A
G
Val (start)
alanine
glutamate
glycine
G

Amino acid Material information

Amino acid Summary

Chinese Name: amino acid
Chinese alias:
English Name: Amino Acids
English alias: Aminosyn; Amino acids, corn gluten Corn gluten amino; acids; Travasol; AMI-U-II; Albumaid X; Alkyl amino acid; Aminess amino acids 5.2% essential w/ histadine; Amino Acid Blend; Amino acids solution, Moripron-F Aminocarboxylic acids; Aminogen; G; Aminomix; Aminosyn 10%; Aminosyn 10%; Aminosyn 3.5% (ph6) in plastic container; Aminosyn 3.5%; Aminosyn 5%; Aminosyn 7%; Aminosyn 7% (ph6);
CAS:65072-01-7
EINECS:-
Molecular formula: RCHNH Two COOH

Amino acid Nature

Organic compounds containing an amino group and carboxyl group. The formula is: H Two N - R - COOH. A colorless crystal, melting point of considerable. Both the nature and properties of amine, carboxylic acid. According to the amino groups on the carbon chain from the carboxyl terminal position, can be divided into alpha, beta, gamma, Omega amino acid etc..

Amino acid Common rumors

Rumor 1: the amino and carboxyl groups are directly connected to a -CH- structure that is the amino acid
Rumor 2: natural amino acids are alpha amino acid
Rumor 3 : in the following molecules, some amino acids, some not, please answer after careful analysis
 The corresponding exercises The corresponding exercises
The problem appeared in at least 09 years about five school final exam (forty-second questions), 13 years in Baicheng final exam (fifty-first questions).
Refute :
In the higher education press Wang Jingyan's "biochemistry" on page 129th clearly pointed out "(amino acid)...... However, there are some beta, gamma or delta - amino acids". Which not only includes the amino acid amino and carboxyl amino acids are directly connected to a -CH- on the structure (i.e. alpha amino acid), but also other different amino acids on carbon chain amino carboxyl terminal position of the distance.