Cell Biology Revision Sheet

1. 📌 Essentials

• All living organisms are composed of cells, the fundamental units of life.
• Cells are classified into prokaryotic (no nucleus) and eukaryotic (nucleus present).
• The nucleus contains genetic material and controls cellular activities.
• Organelles like mitochondria produce energy;osomes synthesize proteins.
• The cell membrane is a phospholipid bilayer regulating substance exchange- Cell walls provide structural support; composition varies (cellulose, chitin, peptidoglycan).
• Cytoskeleton maintains cell shape and facilitates intracellular transport.
• Prokaryotic DNA is in the cytoplasm; eukaryotic DNA is in the nucleus.
• Lysosomes degrade waste; vacuoles store nutrients and maintain turgor in plants.
• Chloroplasts perform photosynthesis in plant cells.

2. 🧩 Key Structures & Components