AP Biology Questions on Lysosomes and Autophagy

📚 Quick Study Guide

• 🔬 Lysosomes: These are membrane-bound organelles containing hydrolytic enzymes that break down various biomolecules. Think of them as the cell's recycling center.
• ♻️ Autophagy: This is a cellular process where the cell digests its own components, like damaged organelles or misfolded proteins. It's crucial for cell survival and homeostasis.
• 🔑 Key Functions of Lysosomes:
  • 🦠 Breaking down bacteria and viruses (phagocytosis).
  • 🍎 Degrading macromolecules (proteins, lipids, carbohydrates, nucleic acids).
  • 🌱 Recycling cellular components (autophagy).
• 💡 Key Functions of Autophagy:
  • 🛡️ Protecting against neurodegeneration.
  • 💪 Providing energy during starvation.
  • 🚧 Removing damaged organelles.
• 🧪 Enzymes in Lysosomes: These enzymes function best in an acidic environment (pH ~4.5-5.0).
• 🧬 Autophagosome Formation: A double-membrane structure that engulfs the material to be degraded.
• 🎯 Relationship: Autophagosomes deliver their contents to lysosomes for degradation.

Practice Quiz

1. Which of the following is the primary function of lysosomes?
   1. A. Protein synthesis
   2. B. Lipid synthesis
   3. C. Intracellular digestion
   4. D. Energy production
2. What is autophagy?
   1. A. Cell division
   2. B. Programmed cell death
   3. C. Self-eating of cellular components
   4. D. DNA replication
3. Lysosomal enzymes are most active at what pH?
   1. A. pH 7.4
   2. B. pH 2.0
   3. C. pH 4.5-5.0
   4. D. pH 9.0
4. Which organelle fuses with a lysosome to digest worn-out organelles?
   1. A. Endoplasmic reticulum
   2. B. Golgi apparatus
   3. C. Mitochondrion
   4. D. Nucleus
5. What structure delivers its contents to lysosomes for degradation during autophagy?
   1. A. Ribosome
   2. B. Autophagosome
   3. C. Proteasome
   4. D. Peroxisome
6. A cell experiencing starvation might upregulate which process?
   1. A. DNA replication
   2. B. Autophagy
   3. C. Protein synthesis
   4. D. Exocytosis
7. Which of the following is NOT a function of autophagy?
   1. A. Removal of damaged organelles
   2. B. Protection against neurodegeneration
   3. C. Production of new proteins
   4. D. Providing energy during starvation