Amino acids?

Question

in what way do amino acids differ from each other?

Answer 1

Amino acids in proteins

Amino acids are the basic structural building units of proteins. They form short polymer chains called peptides or longer chains either called polypeptides or proteins. The process of such formation from an mRNA template is known as translation, which is part of protein synthesis.

Twenty amino acids are encoded by the standard genetic code and are called proteinogenic or standard amino acids. The mean mass of the standard amino acids, weighted by abundance in proteins, is roughly 111 Daltons.

Other amino acids contained in proteins are usually formed by post-translational modification, which is modification after translation in protein synthesis. These modifications are often essential for the function or regulation of a protein.


Non-protein amino acids
Hundreds of types of non-protein amino acids have been found in nature and they have multiple functions in living organisms. Microorganisms and plants can produce uncommon amino acids. In microbes, examples include 2-aminoisobutyric acid and lanthionine, which is a sulfide-bridged alanine dimer. Both these amino acids are both found in peptidic lantibiotics such as alamethicin. While in plants, 1-Aminocyclopropane-1-carboxylic acid is a small disubstituted cyclic amino acid that is a key intermediate in the production of the plant hormone ethylene.

In humans, non-protein amino acids also have biologically-important roles. Glycine, gamma-aminobutyric acid and glutamate are neurotransmitters and many amino acids are used to synthesize other molecules, for example:

Tryptophan is a precursor of the neurotransmitter serotonin
Glycine is a precursor of porphyrins such as heme
Arginine is a precursor of the hormone nitric oxide
Carnitine is used in lipid transport within a cell,
Ornithine is a precursor of polyamines,
Homocysteine is an intermidiate in S-adenosylmethionine recycling
Also present are hydroxyproline, hydroxylysine, and sarcosine. The thyroid hormones are also alpha-amino acids.

Some amino acids have even been detected in meteorites, especially in a type known as carbonaceous chondrites. This observation has prompted the suggestion that life may have arrived on earth from an extraterrestrial source.


Hydrophilic and hydrophobic amino acids
Depending on the polarity of the side chain, aminoacids can be hydrophilic or hydrophobic to various degrees. This influences their interaction with other structures, both within the protein itself and within other proteins. The distribution of hydrophilic and hydrophobic aminoacids determines the tertiary structure of the protein, and their physical location on the outside structure of the proteins influences their quaternary structure. For example, soluble proteins have surfaces rich with polar aminoacids like serine and threonine, while integral membrane proteins tend to have outer ring of hydrophobic aminoacids that anchors them to the lipid bilayer, and proteins anchored to the membrane have a hydrophobic end that locks into the membrane. Similarly, proteins that have to bind to positively-charged molecules have surfaces rich with negatively charged aminoacids like glutamate and aspartate, while proteins binding to negatively-charged molecules have surfaces rich with positively charged chains like lysine and arginine.

Hydrophilic and hydrophobic interactions of the proteins do not have to rely only on the sidechains of aminoacids themselves. By various posttranslational modifications other chains can be attached to the proteins, forming hydrophobic lipoproteins or hydrophilic glycoproteins.


Nonstandard amino acids
Aside from the twenty standard amino acids and the two special amino acids, there are a vast number of "nonstandard amino acids". Two of these can be encoded in the genetic code, but are rather rare in proteins.

At least two others are also coded by DNA in a non-standard manner:

Selenocysteine is incorporated into some proteins at a UGA codon, which is normally a stop codon.
Pyrrolysine is used by some methanogenic bacteria in enzymes that they use to produce methane. It is coded for with the codon UAG.
Examples of nonstandard amino acids that are not found in proteins include the sulfur-containing taurine and the neurotransmitters GABA and dopamine. Other examples are lanthionine, 2-Aminoisobutyric acid, and dehydroalanine. Nonstandard amino acids often occur in the metabolic pathways for standard amino acids - for example ornithine and citrulline occur in the urea cycle, part of amino acid breakdown.

Nonstandard amino acids are usually formed through modifications to standard amino acids. For example, taurine can be formed by the decarboxylation of cysteine, while dopamine is synthesized from tyrosine and hydroxyproline is made by a posttranslational modification of proline (common in collagen).

Over 79 amino acids were found in the primitive Murchison meteorite.

Answer 2

They are different from each other because of their polarity and acidity. They also differ from their chemical structure.
Another reason why they are different from each other is because of on how they were synthesized.
Example, Alanine is most commonly made by transfer of an amine group to pyruvate;
The synthesis of Serine and glycine starts with the oxidation of 3-phosphoglycerate forming 3-phosphohydroxypyruvate and NADH. A transamination reaction with glutamic acid forms 3-phosphoserine and removal of Pi yields serine.

Answer 3

BEST ANSWER a chemical subtances that neutralizes alkasin, dissolve some metals, and turns litmus red typically a corrosive or sour tasting of this kind

Answer 4

Vaginer