What factor could be investigated to assess its effect on membrane permeability?

Temperature is a crucial factor to investigate when assessing its effect on membrane permeability because it directly influences the fluidity and structure of the lipid bilayer in cell membranes. As temperature increases, the kinetic energy of the molecules in the membrane also increases, which can lead to a more fluid membrane. This increased fluidity may allow substances to pass through the membrane more easily, potentially leading to greater permeability.

For instance, in biological systems, when cells are exposed to higher temperatures, the increased motion of the phospholipids can create spaces within the membrane, allowing molecules that typically wouldn't permeate the membrane to do so. Conversely, at lower temperatures, the membrane becomes more rigid, which could restrict permeability.

Investigating temperature's impact provides valuable insights into how cells adjust to different environmental conditions and can be particularly relevant in experiments involving plant cells, such as beetroot, where the release of pigment can be used as an indicator of membrane integrity and permeability.