HSC Biology — Module 1
Membrane Transport — Flashcards & Quiz
Cell membranes regulate what enters and leaves the cell, and HSC Biology Module 1 expects you to distinguish passive mechanisms (diffusion, osmosis, facilitated diffusion) from active transport and bulk transport. Exam questions typically give a scenario — glucose uptake, ion channels, water balance — and ask you to identify the mechanism, justify the energy requirement, and link it back to the fluid mosaic structure.
Sample Flashcards
Q1: Define diffusion and give one biological example.
Diffusion is the net movement of particles from a region of high concentration to low concentration down the concentration gradient, requiring no energy.
Q2: What is osmosis?
Osmosis is the net movement of water molecules from a region of low solute concentration to high solute concentration across a selectively permeable membrane.
Q3: Explain facilitated diffusion.
Facilitated diffusion is passive transport of molecules across the membrane through specific carrier or channel proteins, moving down the concentration gradient without energy input.
Q4: How does active transport differ from passive transport?
Active transport moves substances against their concentration gradient (low to high) and requires energy (ATP). Passive transport moves substances down the gradient without energy.
Q5: Define endocytosis and exocytosis.
Endocytosis: the cell membrane folds inward to engulf substances into a vesicle (phagocytosis for solids, pinocytosis for liquids). Exocytosis: vesicles fuse with the membrane to release contents outside the cell.
Sample Quiz Questions
Q1: Diffusion requires energy input from the cell (ATP).
Answer: FALSE
Diffusion is a passive process that does not require ATP. Particles move down their concentration gradient due to their own kinetic energy.
Q2: Osmosis is the movement of water from a region of low solute concentration to high solute concentration across a selectively permeable membrane.
Answer: TRUE
Osmosis specifically involves water moving across a selectively permeable membrane towards the region of higher solute concentration.
Q3: Facilitated diffusion uses carrier or channel proteins and requires ATP.
Answer: FALSE
Facilitated diffusion uses carrier or channel proteins but is still passive — it moves molecules DOWN their concentration gradient without ATP.
Related Concepts
Last updated: March 2026 · 6 flashcards · 6 quiz questions