Cyanide is a toxic substance which can poison the metabolic reactions of the organisms. The cyanide act during cellular respiration especially during the electron transport chain by blocking the transfer of an electron to the oxygen. This transfer of oxygen is blocked as cyanide binds to the complex IV subunits. This stops the generation of the ATP molecules and thus cells die.
If the ATP will not be produced than the physiological responses in the cell which involves the ATP will get blocked like the movement in the cell, of the cell, the process of cell division and the transport which utilizes the ATP.
Since diffusion is a process which does not uses the ATP, therefore, it will be least affected by the cyanide.
The process of diffuse transports the substances in the direction of their concentration gradients. Diffusion of substance from the region of their higher to that of the lower concentration does not require any energy. Being a passive process, diffusion can be carried out by a cell irrespective of the status of its ATP supply. Therefore, an animal cell containing a small amount of cyanide can transport substances by diffusion.
Plasmodesmata are channels between adjacent plant cells, while gap junctions are channels between adjacent animal cells. However, their structures are quite different. A tight junction is a watertight seal between two adjacent cells, while a desmosome acts like a spot weld.
