Final answer:
The lateral movement of integral membrane proteins is primarily characterized by random motion, described by the fluid mosaic model, but can also be restricted due to attachment to the cytoskeleton or within membrane domains.
Step-by-step explanation:
The characteristics of the lateral movement of integral membrane proteins include random movement, as they float within the lipid bilayer of the cell membrane. This movement is often described by the fluid mosaic model, which suggests that the membrane behaves like a fluid with proteins and lipids moving laterally within the layer. However, the movement is not entirely unrestricted; proteins attached to the cytoskeleton or within certain membrane domains may have restricted mobility, and crossing between these domains, or fence-jumping, might require extra kinetic energy. Hence, while the default movement pattern of integral proteins tends to be random, or Brownian, it can sometimes be restricted in certain regions.