Cell Biology
Cell biology and molecular biology explain how cells are organized, how membranes and organelles perform specialized functions, and how genetic information is stored, expressed, regulated and transmitted.
General subject summary is free to everyone.
Cell Biology
Subject Summary
The public overview below follows the supplied PhysioVeda Academics subject summary.
Cell biology and molecular biology explain how cells are organized, how membranes and organelles perform specialized functions, and how genetic information is stored, expressed, regulated and transmitted.
A useful framework links cell structure to function: membranes control exchange and signaling, the cytoskeleton organizes shape and transport, organelles compartmentalize metabolism, and the nucleus coordinates genome activity.
Molecular biology focuses on DNA replication and repair, RNA synthesis and processing, protein synthesis, gene regulation, cell signaling, the cell cycle, programmed cell death and molecular mechanisms of disease.
For health sciences, these principles provide the foundation for understanding inherited disease, cancer, infection, drug targets, regenerative medicine, biomarkers and modern molecular diagnostic techniques.
This summary follows the uploaded PhysioVeda Academics structure from basic cell organization through membranes, organelles, genome biology, gene expression, signaling, cell division, cancer, laboratory techniques and clinical applications.
Whole-subject high-yield numbers
Use these supplied values and key facts for quick whole-subject revision.
| Typical plasma membrane thickness | About 7-10 nm |
| Cytoskeletal filament diameters | Actin ~7 nm; intermediate filaments ~10 nm; microtubules ~25 nm |
| Eukaryotic cytosolic ribosome | 80S = 60S + 40S subunits |
| Mitochondrial ribosome | Distinct from cytosolic ribosomes; mitochondria retain their own translation system |
| Human diploid chromosome number | 46 chromosomes = 23 pairs |
| Approximate haploid nuclear genome | ~3.2 billion base pairs |
| Nucleosome core DNA | ~147 base pairs wrapped around a histone octamer |
| DNA synthesis direction | 5-prime to 3-prime |
| Standard genetic-code codons | 64 total: 61 sense codons + 3 stop codons |
| Cell-cycle sequence | G1 -> S -> G2 -> M; G0 is a quiescent state outside active cycling |
| Mitosis outcome | 2 genetically similar daughter cells |
| Meiosis outcome | 4 haploid products after two divisions |
| Ideal PCR amplification | Approximately 2^n target copies after n perfectly efficient cycles |
Core references
- Alberts B, Heald R, Johnson A, Morgan D, Raff M, Roberts K, Walter P. Molecular Biology of the Cell. 7th ed. Garland Science; 2022.
- Lodish H, Berk A, Kaiser CA, et al. Molecular Cell Biology. 9th ed. W.H. Freeman/Macmillan Learning; 2021.
- Karp G, Iwasa J, Marshall W. Karp's Cell and Molecular Biology: Concepts and Experiments. 9th ed. Wiley; 2020.
- Watson JD, Baker TA, Bell SP, Gann A, Levine M, Losick R. Molecular Biology of the Gene. 8th ed. Pearson; 2017.
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