Unfolding proteins
One end of the protein titin is bound to a gold substrate while the other end is held by the tip of the atomic force microscope. The protein fragment resembles beads on a string, where each bead is a tightly coiled portion of the molecule. As the molecule is stretched, the force increases until one of the coils unravels. The process continues until the next coil unfolds and results in the saw-tooth pattern.