Title: Comprehensive Study Guide on Cells
## I. Introduction to Cells
### A. Definition
- Cells are the basic structural and functional units of living organisms.
- They are classified into prokaryotic and eukaryotic cells.
### B. Cell Theory
1. The cell is the fundamental unit of life.
2. All living organisms are composed of one or more cells.
3. All cells arise from pre-existing cells.
## II. Prokaryotic Cells
### A. Characteristics
1. Lack a true nucleus.
2. Simple structure.
3. Examples: bacteria and archaea.
### B. Components
1. Cell membrane.
2. Cytoplasm.
3. Ribosomes.
4. DNA in a nucleoid region.
## III. Eukaryotic Cells
### A. Characteristics
1. Have a true nucleus.
2. Complex structure.
3. Examples: plants, animals, fungi, and protists.
### B. Cell Organelles
1. Nucleus: Control center of the cell.
2. Mitochondria: Powerhouse of the cell.
3. Endoplasmic Reticulum (ER): Site of protein and lipid synthesis.
4. Golgi Apparatus: Packages and transports cellular products.
5. Vacuole: Storage organelle.
6. Chloroplasts (in plant cells): Site of photosynthesis.
7. Lysosomes: Digestive organelles.
## IV. Cell Membrane
### A. Structure
1. Phospholipid bilayer.
2. Proteins and carbohydrates.
3. Selective permeability.
### B. Functions
1. Maintains cell shape.
2. Controls entry and exit of substances.
## V. Cell Cycle
### A. Phases
1. Interphase: G1, S, G2.
2. Mitosis: Prophase, Metaphase, Anaphase, Telophase.
3. Cytokinesis: Division of the cytoplasm.
### B. Regulation
1. Checkpoints.
2. Cyclins and cyclin-dependent kinases (CDKs).
## VI. Cellular Respiration
### A. Glycolysis
1. Occurs in the cytoplasm.
2. Breaks down glucose into pyruvate.
### B. Krebs Cycle (Citric Acid Cycle)
1. Takes place in the mitochondria.
2. Generates NADH and FADH2.
### C. Electron Transport Chain
1. Located in the inner mitochondrial membrane.
2. Produces ATP through oxidative phosphorylation.
## VII. Photosynthesis
### A. Light Reactions
1. Occur in the thylakoid membrane.
2. Generate ATP and NADPH.
### B. Calvin Cycle
1. Takes place in the stroma.
2. Produces glucose from CO2.
## VIII. Cell Division in Prokaryotes
### A. Binary Fission
1. Simple cell division process.
2. Chromosome replication and cell division.
## IX. Stem Cells
### A. Types
1. Totipotent.
2. Pluripotent.
3. Multipotent.
### B. Applications
1. Regenerative medicine.
2. Cell-based therapies.
## X. Cell Communication
### A. Signaling Pathways
1. Reception.
2. Transduction.
3. Response.
### B. Cell Signaling Molecules
1. Hormones.
2. Neurotransmitters.
## XI. Cellular Transport
### A. Passive Transport
1. Diffusion.
2. Osmosis.
3. Facilitated diffusion.
### B. Active Transport
1. Sodium-potassium pump.
2. Endocytosis and exocytosis.
## XII. Disorders Related to Cells
### A. Cancer
1. Uncontrolled cell growth.
2. Causes and prevention.
### B. Genetic Disorders
1. Examples: Down syndrome, cystic fibrosis.
## XIII. Laboratory Techniques
### A. Microscopy
1. Light microscopy.
2. Electron microscopy.
### B. Cell Culture
1. Techniques for growing cells outside the body.
## XIV. Ethical Considerations
### A. Cloning
1. Reproductive cloning.
2. Therapeutic cloning.
### B. Genetic Engineering
1. CRISPR technology.
2. Ethical implications.
## XV. Conclusion
- Recap of key concepts.
- Importance of understanding cell biology.
This comprehensive study guide covers various aspects of cell biology, providing a solid
foundation for understanding the structure and function of cells, as well as their role in
living organisms.