Residual elongation

Figure 8. Cumulative periodogram of an elongational residual series.

The elongation of a stretched fiber is best described as a combination of instantaneous extension and a time-dependent extension or creep. This viscoelastic behavior is common to many textile fibers, including acetate. Conversely, recovery of viscoelastic fibers is typically described as a combination of immediate elastic recovery, delayed recovery, and permanent set or secondary creep. The permanent set is the residual extension that is not recoverable. These three components of recovery for acetate are given in Table 1 (4). The elastic recovery of acetate fibers alone and in blends has also been reported (5). In textile processing strains of more than 10% are avoided in order to produce a fabric of acceptable dimensional or shape stabiUty. 

Fig. 3. Elastomer properties as a function of monomer composition, butyl acrylate (BA), ethyl acrylate (FA), and methoxyethyl acrylate (MEA). (a), (—) glass-transition temperature (------------) swelling in ASTM No. 3 oil (b) (-) residual elongation at break, %, after heat aging.

Phalloidin and phallacidin are cyclic peptides from the mushroom Amanita phalloides that stabilize F-actin. Phalloidin binds to residues 114-118 of an actin protomere and blocks nucleotide exchange without interfering with nucleotide hydrolysis. It enhances the rate of nucleation as well as that of elongation. It slowly penetrates the cell membrane and is used for immunocytochemical localization of F-actin. 

Template binding RNA polymerase (RNAP) binds to DNA and locates a promoter (P) melts the two DNA strands to form a preinitiation complex (PIQ. (2) Chain initiation RNAP holoenzyme (core + one of multiple sigma factors) catalyzes the coupling of the first base (usually ATP or GTP) to a second ribonucleoside triphosphate to form a dinucleotide. (3) Chain elongation Successive residues are added to the 3 -OH terminus of the nascent RNA molecule. (4) Chain termination and release The completed RNA chain and RNAP are released from the template. The RNAP holoenzyme re-forms, finds a promoter, and the cycle is repeated. 

Figure 38-8. Diagrammatic representation of the peptide elongation process of protein synthesis. The small circles labeled n - 1, n, n -I-1, etc, represent the amino acid residues of the newly formed protein molecule. EFIA and EF2 represent elongation factors 1 and 2, respectively. The peptidyl-tRNA and aminoacyl-tRNA sites on the ribosome are represented by P site and A site, respectively.

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