FIGURE 5.

Effective chain-end boundary conditions induced by bead rotational fluctuations. The unnormalized probability density is shown versus for a bead of radius R = 250 nm. The different curves correspond to different values of the applied force. In this calculation, the attachment of the chain to the bead is half-constrained: in the absence of bead rotational fluctuations, the probability density is zero for cos γ < 0 and constant for cos γ > 0. This step function is approached for a large force. For smaller values of FR, the probability density is smeared out and approaches a constant value (independent of cos γ).