How to Revise Biological membranes — OCR A-Level Biology
Biological membranes is a topic in the OCR A-Level Biology specification. This guide covers learning objectives, examiner tips, common mistakes, and key terminology to help you revise effectively.
Examiner Tips for Biological membranes
- Ensure you can explain the fluid mosaic model clearly, referencing all key components.
- Be prepared to interpret data from practical investigations into membrane permeability.
- Use precise terminology when describing movement across membranes (e.g., 'facilitated diffusion' vs 'active transport').
- Link membrane structure to its function in cell signalling.
Common Mistakes in Biological membranes
- Confusing the roles of different membrane proteins.
- Failing to distinguish between passive and active transport mechanisms.
- Misunderstanding the effect of temperature on membrane permeability (e.g., membrane fluidity vs. protein denaturation).
- Incorrectly describing the role of ATP in membrane transport.
Key Marking Points
- Roles of membranes as partially permeable barriers between cells, organelles, and cytoplasm.
- Membranes as sites of chemical reactions and cell communication (cell signalling).
- Components of the fluid mosaic model: phospholipids, cholesterol, glycolipids, proteins, and glycoproteins.
- Role of membrane-bound receptors for hormones and drugs.
- Effects of temperature and solvents on membrane structure.
- Mechanisms of movement: diffusion, facilitated diffusion (passive), active transport, endocytosis, and exocytosis (requiring ATP).