AP Biology Questions on Plasma Membrane Transport Mechanisms

📚 Quick Study Guide

• 🔬 The plasma membrane is selectively permeable, controlling what enters and exits the cell.
• 📦 Passive transport requires no energy and follows the concentration gradient (high to low). Examples: diffusion, osmosis, facilitated diffusion.
• 💧 Osmosis is the movement of water across a semi-permeable membrane from an area of high water concentration to an area of low water concentration.
• 💪 Active transport requires energy (ATP) and can move substances against the concentration gradient (low to high).
• 🔑 Types of active transport include: primary active transport (e.g., sodium-potassium pump), secondary active transport (co-transport), endocytosis, and exocytosis.
• ➡️ Endocytosis: Cell takes in macromolecules by forming vesicles from the plasma membrane (phagocytosis, pinocytosis, receptor-mediated endocytosis).
• ⬅️ Exocytosis: Cell secretes macromolecules by fusion of vesicles with the plasma membrane.
• ⚖️ Water potential ($\Psi$) predicts the direction water will flow.$\Psi = \Psi_p + \Psi_s$ where $\Psi_p$ is pressure potential and $\Psi_s$ is solute potential.

🧪 Practice Quiz

1. Which of the following transport mechanisms requires the direct input of ATP?
   1. Simple diffusion
   2. Facilitated diffusion
   3. Active transport
   4. Osmosis
2. A cell is placed in a hypertonic solution. What will happen to the cell?
   1. It will swell and possibly burst.
   2. It will shrink.
   3. It will remain the same size.
   4. It will become turgid.
3. Which of the following is an example of passive transport?
   1. Sodium-potassium pump
   2. Endocytosis
   3. Exocytosis
   4. Facilitated diffusion
4. What process is responsible for the movement of oxygen from the lungs into the blood?
   1. Osmosis
   2. Active Transport
   3. Simple Diffusion
   4. Exocytosis
5. Which type of endocytosis involves the ingestion of large particles or cells?
   1. Pinocytosis
   2. Receptor-mediated endocytosis
   3. Phagocytosis
   4. Exocytosis
6. The sodium-potassium pump is an example of:
   1. Simple diffusion
   2. Facilitated diffusion
   3. Primary active transport
   4. Osmosis
7. What is the water potential of a solution with a solute potential of -0.3 MPa and a pressure potential of 0.2 MPa?
   1. -0.5 MPa
   2. 0.5 MPa
   3. -0.1 MPa
   4. 0.1 MPa