CHAPTER 6 • CELL BIOLOGY6.3 Membrane Transport
Cells exchange materials with their surroundings through processes that depend on concentration, membrane structure, and available energy.
Learning objectiveDistinguish passive transport from active transport and relate each process to membrane behaviour.
Figure 6.4 • Schematic representation of transport across a cell membrane.
Check your understanding
1. Why does diffusion not require direct energy input?
2. When would a transport protein be necessary?
3. Explain one difference between facilitated diffusion and active transport.