一場蛋白質的盛宴
Peanut, or groundnut (Arachis hypogaea) are known by many other local names such as earthnut, ground nut, monkey nut, and pig nut. Despite its name and appearance, the peanut is not a nut, but rather a legume. Hypogaea means "under the earth"; after pollination, the flower stalk elongates causing it to bend until the ovary touches the ground. Continued stalk growth then pushes the ovary underground where the mature fruit develops into a legume pod, the peanut.
Most of the edible tissue on the feet consists of skin and tendons, with no muscle. Collagen is a group of naturally occurring proteins found in animals, in the form of elongated fibrils, is mostly found in fibrous tissues such as tendon, ligament and skin, and is also abundant in cornea, cartilage, bone, blood vessels, the gut, and intervertebral disc.
Peanut nutritional value per 100 g (3.5 oz).
* Percentages are relative to US recommendations for adults
Collagen is a composed of a triple helix, which generally consists of two identical chains (α1) and an additional chain that differs slightly in its chemical composition (α2). The most common motifs in the amino acid sequence of collagen are Glycine-Proline-X and Glycine-X-Hydroxyproline, where X is any amino acid other than glycine, proline or hydroxyproline. Abundance in Skin (Residues/1000):
Proteinogenic ("protein building") amino acids are amino acids that are precursors to proteins, and are produced by cellular machinery coded for in the genetic code of any organism. There are 22 standard amino acids, but only 21 are found in eukaryotes. Proteinogenic amino acids can be condensed into a polypeptide (the subunit of a protein) through a process called translation (the second stage of protein biosynthesis, part of the overall process of gene expression).
In contrast, non-proteinogenic amino acids are either not incorporated in proteins (like GABA, L-DOPA, or triiodothyronine), or are not produced directly and in isolation by standard cellular machinery (like hydroxyproline and selenomethionine). Non-proteinogenic amino acids are incorporated in nonribosomal peptides, which are not produced by the ribosome during translation.
Humans can synthesize 11 of these 20 from each other or from other molecules of intermediary metabolism. The other 9 must be consumed in the diet and so are thus called essential amino acids. The essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Peanut has all 9 essential amino acids. Collagen in animal skin has 8 with tryptophan is missing. Peanut has cystine but collagen does not.
9 Essential Amino Acids
Amino acids that find in peanuts:
Amino acids that find in collagen:
Peanut, or groundnut (Arachis hypogaea) are known by many other local names such as earthnut, ground nut, monkey nut, and pig nut. Despite its name and appearance, the peanut is not a nut, but rather a legume. Hypogaea means "under the earth"; after pollination, the flower stalk elongates causing it to bend until the ovary touches the ground. Continued stalk growth then pushes the ovary underground where the mature fruit develops into a legume pod, the peanut.
Most of the edible tissue on the feet consists of skin and tendons, with no muscle. Collagen is a group of naturally occurring proteins found in animals, in the form of elongated fibrils, is mostly found in fibrous tissues such as tendon, ligament and skin, and is also abundant in cornea, cartilage, bone, blood vessels, the gut, and intervertebral disc.
Peanut nutritional value per 100 g (3.5 oz).
| Carbohydrates | 21 g |
| Fat | 48 g |
| saturated | 7 g |
| monounsaturated | 24 g |
| polyunsaturated | 16 g |
| Protein | 25.3055 g |
| Water | 4.26 g |
| Thiamine (vit. B1) | 0.6 mg (52%) |
| Niacin (vit. B3) | 12.9 mg (86%) |
| Pantothenic acid (B5) | 1.8 mg (36%) |
| Vitamin B6 | 0.3 mg (23%) |
| Folate (vit. B9) | 246 μg (62%) |
| Vitamin C | 0.0 mg (0%) |
| Calcium | 62 mg (6%) |
| Iron | 2 mg (15%) |
| Magnesium | 184 mg (52%) |
| Phosphorus | 336 mg (48%) |
| Potassium | 332 mg (7%) |
| Zinc | 3.3 mg (35%) |
Protein |
25.3055 | |
| Glutamic acid | 5.243 | 20.72% |
| Aspartic acid | 3.06 | 12.09% |
| Arginine | 3.001 | 11.86% |
| Leucine | 1.627 | 6.43% |
| Glycine | 1.512 | 5.97% |
| Phenylalanine | 1.3 | 5.14% |
| Serine | 1.236 | 4.88% |
| Proline | 1.107 | 4.37% |
| Valine | 1.052 | 4.16% |
| Tyrosine | 1.02 | 4.03% |
| Alanine | 0.997 | 3.94% |
| Lysine | 0.901 | 3.56% |
| Isoleucine | 0.882 | 3.49% |
| Threonine | 0.859 | 3.39% |
| Histidine | 0.634 | 2.51% |
| Cystine | 0.322 | 1.27% |
| Methionine | 0.308 | 1.22% |
| Tryptophan | 0.2445 | 0.97% |
Collagen is a composed of a triple helix, which generally consists of two identical chains (α1) and an additional chain that differs slightly in its chemical composition (α2). The most common motifs in the amino acid sequence of collagen are Glycine-Proline-X and Glycine-X-Hydroxyproline, where X is any amino acid other than glycine, proline or hydroxyproline. Abundance in Skin (Residues/1000):
| X | Amino Acid | Mammal | Fish |
| Gly | Glycine | 329 | 339 |
| Pro | Proline | 126 | 108 |
| Ala | Alanine | 109 | 114 |
| Hyp | Hydroxyproline | 95 | 67 |
| Glu | Glutamic acid | 74 | 76 |
| Arg | Arginine | 49 | 52 |
| Asp | Aspartic acid | 47 | 47 |
| Ser | Serine | 36 | 46 |
| Lys | Lysine | 29 | 26 |
| Leu | Leucine | 24 | 23 |
| Val | Valine | 22 | 21 |
| Thr | Threonine | 19 | 26 |
| Phe | Phenylalanine | 13 | 14 |
| Ile | Isoleucine | 11 | 11 |
| Hyl | Hydroxylysine | 6 | 8 |
| Met | Methionine | 6 | 13 |
| His | Histidine | 5 | 7 |
| Tyr | Tyrosine | 3 | 3 |
Proteinogenic ("protein building") amino acids are amino acids that are precursors to proteins, and are produced by cellular machinery coded for in the genetic code of any organism. There are 22 standard amino acids, but only 21 are found in eukaryotes. Proteinogenic amino acids can be condensed into a polypeptide (the subunit of a protein) through a process called translation (the second stage of protein biosynthesis, part of the overall process of gene expression).
In contrast, non-proteinogenic amino acids are either not incorporated in proteins (like GABA, L-DOPA, or triiodothyronine), or are not produced directly and in isolation by standard cellular machinery (like hydroxyproline and selenomethionine). Non-proteinogenic amino acids are incorporated in nonribosomal peptides, which are not produced by the ribosome during translation.
Humans can synthesize 11 of these 20 from each other or from other molecules of intermediary metabolism. The other 9 must be consumed in the diet and so are thus called essential amino acids. The essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Peanut has all 9 essential amino acids. Collagen in animal skin has 8 with tryptophan is missing. Peanut has cystine but collagen does not.
9 Essential Amino Acids
| Histidine | Used by many proteins as a regulatory mechanism. However only a few histidines are needed for this, so it is comparatively scarce. |
| Isoleucine | Their molecules are rigid and have large aliphatic hydrophobic side chains. Their mutual hydrophobic interactions are important for the correct folding of proteins, as these chains tend to be located inside of the protein molecule. |
| Leucine | Behaves similarly to isoleucine |
| Lysine | Behaves similar to arginine. Contains a long flexible side-chain with a positively-charged end. DNA-binding proteins have their active regions rich with arginine and lysine. The strong charge makes these two amino acids prone to be located on the outer hydrophilic surfaces of the proteins; when they are found inside, they are usually paired with a corresponding negatively-charged amino acid, e.g., aspartate or glutamate. |
| Methionine | Always the first amino acid to be incorporated into a protein. It's methyl group, if activated, is used in many reactions where a new carbon atom is being added to another molecule. |
| Phenylalanine | The biggest amino acids, contain large rigid aromatic group on the side-chain. Like isoleucine, leucine and valine, these are hydrophobic and tend to orient towards the interior of the folded protein molecule. |
| Threonine | Has a short group ended with a hydroxyl group. Both threonine and serine are very hydrophilic, the outer regions of soluble proteins tend to be rich with them. |
| Tryptophan | Behaves similarly to phenylalanine and tyrosine. Precursor of serotonin. Naturally fluorescent. |
| Valine | Behaves similarly to isoleucine |
Amino acids that find in peanuts:
| Glutamic acid | Behaves similarly to aspartic acid. Has longer, slightly more flexible side chain. |
| Arginine | Functionally similar to lysine. |
| Aspartic acid | Usually is located on the outer surface of the protein, making it water-soluble. Binds to positively-charged molecules and ions, often used in enzymes to fix the metal ion. |
| Cystine | A dimeric amino acid formed by the oxidation of two cysteine residues that covalently link to make a disulfide bond. Through formation of disulfide bonds within and between protein molecules, cystine is a significant determinant of the tertiary structure of most proteins. Cysteine is an α-amino acid. The thiol side chain in cysteine often participates in enzymatic reactions, serving as a nucleophile. |
Amino acids that find in collagen:
| Glycine | It is not optically active. It is the smallest amino acid, rotates easily, adds flexibility to the protein chain. As too much flexibility is usually not desired, as a structural component it is less common than alanine. |
| Proline | Can disrupt protein folding structures like α helix or β sheet, forcing the desired kink in the protein chain. Common in collagen, where it often undergoes a post-translational modification to hydroxyproline. |
| Alanine | Behaves fairly neutrally, and can be located in both hydrophilic regions on the protein outside and the hydrophobic areas inside. |
| Hydroxyproline | A common non-proteinogenic amino acid. It is produced by hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase following protein synthesis. Although it is not directly incorporated into proteins, hydroxyproline comprises roughly 4% of all amino acids found in animal tissue, more than seven amino acids which are directly incorporated. Hydroxyproline and proline play key roles for collagen stability. They permit the sharp twisting of the collagen helix. |
| Hydroxylysine | It arises from a post-translational hydroxy modification of lysine. It is most widely known as a component of collagen. |
