Selective Permeability
Organizations need to be simultaneously closed enough to maintain identity and open enough to adapt to change.
The cell membrane is *selectively permeable*. Some molecules pass through freely. Others require specific transport mechanisms. Some are actively pumped in or out using energy. Some are blocked entirely.
For larger molecules, the membrane contains hundreds of different protein types embedded in the bilayer, each with a specific job:
**Channel proteins** form tunnels that allow specific molecules to pass through. They're passive - things flow through based on concentration gradients.
**Pump proteins** actively transport molecules against concentration gradients, using energy (ATP) to move things from areas of low concentration to high concentration. Your cells spend tremendous energy running these pumps.
**Receptor proteins** detect signals from outside the cell - hormones, neurotransmitters, growth factors - and trigger responses inside.
**Recognition proteins** act like ID badges, allowing immune cells to distinguish your cells from bacterial invaders.
Business Application of Selective Permeability
Organizations need to be simultaneously closed enough to maintain identity and open enough to adapt to change. The biological solution is selective permeability: some things enter freely (channels), some require active acquisition (pumps), some are sensed but not admitted (receptors), and some are excluded entirely. Strategic boundary design determines what your organization becomes.