Bending motions

Figure A3.13.10. Time-dependent probability density of the isolated CH clnomophore in CHF. Initially, tlie system is in a Fenni mode with six quanta of stretching and zero of bending motion. The evolution occurs within the multiplet with chromophore quantum number A = 6 = A + 1 = 7). Representations are given...

Interestingly, there are many proteins with two domains that show a very clear hinge-bending motion with an obvious functional significance. Such domains have often been reported in the literature, but were never detected on an automated basis. 

G., Berendsen, H.J.C. The essential dynamics of thermolysin Confirmation of the hinge-bending motion and comparison of simulations in vacuum and water. Proteins 22 (1995) 45-54. 

In an early study of lysozyme ([McCammon et al. 1976]), the two domains of this protein were assumed to be rigid, and the hinge-bending motion in the presence of solvent was described by the Langevin equation for a damped harmonic oscillator. The angular displacement 0 from the equilibrium position is thus governed by... 

The harmonie oseillator energies and wavefunetions eomprise the simplest reasonable model for vibrational motion. Vibrations of a polyatomie moleeule are often eharaeterized in terms of individual bond-stretehing and angle-bending motions eaeh of whieh is, in turn, approximated harmonieally. This results in a total vibrational wavefunetion that is written as a produet of funetions one for eaeh of the vibrational eoordinates. 

It is common to use the symbols v(X-Y), i5(X-Y) and y(X-Y) for stretching, in-plane bending and out-of-plane bending, respectively, in the X-Y group. In addition, the word deformation is often used to imply a bending motion. 

FIGURE 17.7 A mechanism for ciliary motion. The sliding motion of dyneins along one microtnbnle while attached to an adjacent microtnbnle resnlts in a bending motion of the axoneme. 

Repeat the analysis with deuterium oxide (D2O). Are the vibrational frequencies the same, larger or smaller than those in water Rationalize your observations. Are the changes in vibrational frequencies greatest for bond stretching or angle bending motions ... 

Display 1-octyne as a ball-and-spoke model. Examine the individual vibrations (> 1400 cm only), and classify the bands in the experimental infrared spectrum as due to specific motions, e.g., CH, CC and C=C stretching, and HCH and CCC bending motions. 

Polyelectrolyte gels that showed bending motion by shrinking in an electric field139-145 were called electrochemomechanical devices, electro-... 

FIGURE 2 la The three normal vibrational modes of 11,0. Two of these modes are principally stretching motions of the bonds, but mode v2 is primarily bending, (b) The four normal vibrational modes of C02. The first two are symmetrical and antisymmetrical stretching motions, and the last two are perpendicular bending motions. 

Fig. 1. Bending motion of PAANa gel in dc electric fields. PAANa gel in an NaOH solution swells at the anode side and bends toward the cathode like a bimetal... 

An electric field-induced bending of gel makes a worm-like motion feasible [18]. A weakly crosslinked PAMPS gel in a surfactant solution bends toward the anode under dc electric fields. Both ends of the gel are placed on front and rear hooks and are then hung on a plastic ratchet bar. When a varying electric field of 10 V/cm and 0.5 Hz is applied, the gel moves forward in the solution with a bending motion at a velocity of 25 cm/min. 

Bending motions are easier than stretching motions ... 

In the MM3 program, the bending motions are divided into two separate descriptions in-plane and out-of-plane bending. The in-plane bending is shown in Equation 6. Depending on the geometry of the central atom in the... 

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