Overview
This lecture covers the fundamental concepts of cells, including their structure, types, functions, and main components important for biology.
Introduction to Cells
- Cells are the basic structural and functional units of all living organisms.
- All living things are made up of one or more cells.
Types of Cells
- Prokaryotic cells lack a nucleus and membrane-bound organelles (e.g., bacteria).
- Eukaryotic cells have a nucleus and membrane-bound organelles (e.g., plants, animals, fungi, protists).
Cell Structure and Organelles
- The cell membrane controls the entry and exit of substances in and out of the cell.
- The nucleus contains genetic material (DNA) and regulates cell activities.
- Cytoplasm is the fluid that fills the cell and surrounds organelles.
- Mitochondria are the sites of energy (ATP) production through cellular respiration.
- Ribosomes synthesize proteins from amino acids.
- Endoplasmic reticulum (ER) transports materials; rough ER has ribosomes, smooth ER does not.
- Golgi apparatus modifies, sorts, and packages proteins for secretion.
- Lysosomes contain digestive enzymes for breaking down waste.
- In plant cells, chloroplasts carry out photosynthesis and cell walls provide structure.
- Vacuoles store water, nutrients, and waste products.
Differences Between Plant and Animal Cells
- Plant cells have a cell wall, chloroplasts, and large central vacuole.
- Animal cells lack a cell wall and chloroplasts but may have small vacuoles.
Key Terms & Definitions
- Cell — Basic unit of life, structure, and function in living organisms.
- Prokaryote — Cell without a nucleus or membrane-bound organelles.
- Eukaryote — Cell with a nucleus and membrane-bound organelles.
- Organelle — Specialized structure within a cell performing a specific function.
- Mitochondria — Organelle responsible for producing cellular energy.
- Ribosome — Organelle that assembles proteins.
- Cell Membrane — Outer barrier of the cell controlling movement of substances.
- Cytoplasm — Jelly-like substance inside the cell holding organelles.
Action Items / Next Steps
- Review diagrams of plant and animal cells and label their organelles.
- Read textbook section on cell structure and function.
- Complete worksheet on cell organelle identification and functions.