PROTEINS ARE POLYMERS OF AMINO ACIDS

Much of protein engineering concerns attempts to explore the relationship between protein stmcture and function. Proteins are polymers of amino acids (qv), which have general stmcture +H3N—CHR—COO , where R, the amino acid side chain, determines the unique identity and hence the stmcture and reactivity of the amino acid (Fig. 1, Table 1). Formation of a polypeptide or protein from the constituent amino acids involves the condensation of the amino-nitrogen of one residue to the carboxylate-carbon of another residue to form an amide, also called peptide, bond and water. The linear order in which amino acids are linked in the protein is called the primary stmcture of the protein or, more commonly, the amino acid sequence. Only 20 amino acid stmctures are used commonly in the cellular biosynthesis of proteins (qv). 

Proteins are also important nitrogen compounds. They constitute much of the cell materials, and are present in every type of organism known. In humans, muscle tissue, skin, and hair is mostly protein, about half of the dry weight of our bodies. From a chemical point of view, proteins are polymers of amino acids, alpha amine derivatives of carboxylic acids. Only about 20 different amino acids are actually found in proteins. It is the large number of variations in the protein chain, using only these... 

Proteins are polymers of amino acids linked together by peptide bonds the same family of 20 amino acids is employed by all living organisms to construct their proteins. The sequence of amino acids along the chain defines the primary structure of the protein, a species-specific quality. 

Proteins are polymers of amino acids, with each amino acid residue joined to its neighbor by a specific type of covalent bond. (The term residue reflects the loss of the elements of water when one amino acid is joined to another.) Proteins can be broken down (hydrolyzed) to their constituent amino acids by a variety of methods, and the earliest studies of proteins naturally focused on... 

Besides addition polymerization, the other general way to prepare polymers is known as condensation polymerization or step growth polymerization. Much of the pioneering work on condensation polymerization was conducted by Wallace Carothers while he was employed by DuPont. He recognized that many natural polymers are formed from monomers with two reactive functional groups. For example, proteins are polymers of amino acids, which contain both amine and carboxylic acid groups. The formation of amide bonds is used to connect one monomer to another. Carothers s attempts to imitate nature led to a whole industry based on condensation polymerization. 

All proteins are polymers of amino acids. The polymers, or polypeptides, consist of a sequence of up to 20 different L-a-amino acids (residues). For chains under 40 residues the term peptide is frequently used instead of protein. The term protein is generally used to refer to the complete biological molecule in a stable conformation. 

Proteins are the most abundant class of organic compounds in the healthy, lean human body, constituting more than half of its cellular dry weight. Proteins are polymers of amino acids and have molecular weights ranging from approximately 10,000 to more than one million. Biochemical functions of proteins include catalysis, transport, contraction, protection, structure, and metabolic regulation. 

Since proteins are polymers of amino acids, the chemical nature of the amino acid side chains and the order of the amino acids play an important role in establishing the biological properties of the active protein. Proteins may differ from each other according to size, charge density, shape and biological activity. Similarly, protein purification schemes require a similar diverse combination of separation techniques based on the various physicochemical properties of proteins. 

Proteins are polymers of amino acids. These polymers are chains, each containing him-dreds or thousands of amino acids, that fold up into a three-dimensional structure. 

Proteins are polymers of amino acids. With 20 different fundamental amino acids as building blocks, an extraordinarily large variety of proteins can be biosynthesized under the direction of the genetic code. 

In Chapter 19 we will describe the structure of proteins, the molecules that carry out the majority of the biological processes essential to life. Proteins are polymers of amino acids. As the name suggests, amino acids have two essential functional groups, an amino group (—NH2) and a carboxyl group (—COOH). Typically amino acids have the following general structure ... 

The three kinds of polymers that are prevalent in nature are polysaccharides, proteins, and nucleic acids. You have already learned about polysaccharides, which are naturally occurring polymers of sugar subunits (Section 22.18), and nucleic acids are covered in Chapter 27. We will now look at proteins and the structurally similar, but shorter, peptides. Peptides and proteins are polymers of amino acids linked together by amide bonds. The repeating units are called amino acid residues. 

Peptides and proteins are polymers of amino acids linked together by peptide (amide) bonds. A dipeptide contains two amino acid residues, a tripeptide contains three, an oligopeptide contains three to 10, and a polypeptide contains many amino acid residues. Proteins have 40 to 4000 amino acid residues. The amino acids differ only in the substituent attached to the a-carbon. Most amino acids found in nature have the l configuration. 

Proteins are polymers of amino acids that are linked by peptide bonds. All amino acids contain an amino group (-NHj) and a carboxyl group (-COOH). Dipeptides are formed when two amino acids are joined together by peptide bonds. Several covalently linked amino acids are referred to as polypeptides. Proteins can have one or more polypeptides. 

Proteins are polymers of amino acids. Proteins are extremely important since they have a wide range of biological significance. They serve as nutrients, enzymes, cellular products of genes by translation (reflects the hereditary information), building material of muscles and other biologically important structures. 

Proteins are polymers of amino acids. They are the major structural materials in animal systems. All naturally occurring proteins are formed from 22 amino acids, although only 20 are common. The amino acids are linked by peptide bonds. A polypeptide is a polymer formed by linking many amino acids by peptide bonds. 

All proteins are polymers of amino acids, which are bifunctional organic compounds that contain both an amino group and a carboxylate group. Differences in the R groups of amino acids cause differences in the properties of amino acids and proteins. 

PROTEINS We learn that proteins are polymers of amino acids linked with amide (also called peptide) bonds. Proteins are used by organisms for structural support, as molecular transporters and as catalysts for biochemical reactions. 

Proteins and peptides (short proteins) are polymers of amino acids joined by amide groups. One feature common to the structure of many proteins is the j8 sheet, shown... 

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