Overview
This lecture provides a concise review of key cell organelles and structures, highlighting their functions and emphasizing their importance in cell and organism health.
Cell Structures Found in All Cells
- The cell membrane is present in all cells and controls substance entry/exit for homeostasis.
- The cytoplasm is everything inside the cell except the nucleus; it contains cytosol (the jelly-like fluid) and supports organelles.
- Ribosomes are found in all cells and are responsible for protein synthesis.
Structures in Prokaryotic and Some Eukaryotic Cells
- The cell wall offers structure and protection; found in prokaryotes and some eukaryotes (like plant cells).
Structures Unique to Eukaryotic Cells
- Centrioles are present in animal cells (not plant cells), play a role in cell division by helping organize spindle fibers.
- Chloroplasts are found in plant cells (not animal cells), perform photosynthesis to make sugar.
- The endoplasmic reticulum (ER) transports and processes molecules; rough ER makes proteins, smooth ER makes lipids and detoxifies.
- The Golgi apparatus modifies, sorts, and packages molecules for delivery in the cell.
- Lysosomes (mainly in animal cells) contain enzymes to digest and break down substances.
- Mitochondria produce ATP through cellular respiration; ATP is the energy currency of the cell.
- The nucleus stores DNA and controls cell activities.
- Vacuoles store materials such as water, proteins, or waste; central vacuole is large in plant cells, smaller and multiple in animal cells.
Importance of Organelle Function
- Malfunction of organelles (e.g., ER, mitochondria, ribosomes) can lead to diseases affecting the entire organism.
- Understanding organelles is crucial for studying and treating related conditions.
Key Terms & Definitions
- Cell Membrane — barrier controlling entry and exit of substances.
- Cell Wall — structure providing support and protection outside the membrane.
- Cytoplasm — all cell contents except the nucleus; includes cytosol.
- Centrioles — structures aiding in cell division in animal cells.
- Chloroplast — organelle for photosynthesis in plant cells.
- Endoplasmic Reticulum (ER) — network transporting and processing molecules; rough and smooth types.
- Golgi Apparatus — organelle modifying, packaging, and sorting cell products.
- Lysosome — organelle digesting cellular waste and materials.
- Mitochondria — organelle generating ATP energy.
- Nucleus — organelle containing DNA and regulating cell functions.
- Ribosome — structure synthesizing proteins.
- Vacuole — storage organelle in cells; size and number vary by cell type.
Action Items / Next Steps
- Practice naming and identifying functions of cell organelles in plant and animal cell diagrams.
- Review cell organelle functions for upcoming quizzes or tests.