Cellular and Molecular Biology, Immunology and Genetics Terminology

Cellular and Molecular Biology, Immunology and Genetics Terminology

Prepared by Dr. Alper DUNKI

Spot Knowledge

• The nucleus stores DNA; nucleolus produces ribosomes. Defects cause syndromes with skeletal anomalies.
• Mitochondria are key for ATP; dysfunction leads to neuromuscular and metabolic disease.
• Lysosomes degrade waste; defects → storage disorders (e.g., Tay-Sachs).
• ECM (collagen, GAGs, proteoglycans) provides structural support and lubrication.
• Stem cells: mesenchymal stem cells can differentiate into osteoblasts and chondrocytes.

Cellular Structures and Functions

• Nucleus & Nucleolus: Store genetic material, produce ribosomes. Syndromes: Bloom, Treacher Collins, Rothmund-Thomson.
• Cytoplasm: Site of metabolism.
• Mitochondria: ATP production, signaling. Mutations → neuromuscular disease, diabetes, deafness.
• Golgi apparatus: Packages proteins/hormones; linked to secretion disorders.
• Lysosomes: Waste degradation; lysosomal storage diseases (Tay-Sachs, Gaucher).
• Endoplasmic Reticulum: Protein & lipid synthesis.
• Ribosomes: Protein synthesis; ribosomopathies.
• .Cytoskeleton: Shape, motility; defects → cardiomyopathy, genetic deafness

Extracellular Matrix (ECM)

• Provides scaffolding for tissues.
• Components: Collagen (main structural protein), GAGs, fibronectin, laminin.
• GAGs + proteoglycans → cushioning, lubrication

Intracellular Signal Transduction

• Mediated via receptors: GPCRs, ion channels, tyrosine kinases.
• Second messengers: cAMP, Ca²⁺.

DNA & Genetics

• DNA: Double-stranded, stores genetic info.
• Genes: Exons (coding) + introns (non-coding).
• Promoters/Enhancers: Regulate expression.
• Mutations: Basis of inherited disease (Down, DiGeorge).
• Mitochondrial DNA: Maternal inheritance.
• SNPs & Epigenetics: Variation and environment-driven expression

RNA Biology

• mRNA: Protein coding.
• miRNA: Gene regulation.
• rRNA: Part of ribosome, diagnostic use in bacteria

Gene Expression & Protein Synthesis

• Transcription: DNA → RNA.
• Translation: RNA → protein.
• Transcription factors (RUNX2, SOX9, PPAR-γ) regulate bone and cartilage differentiation.
• Post-translational modifications: glycosylation, phosphorylation

Molecular Biology & Protein Techniques

• FISH, CGH: Detect chromosomal abnormalities.
• Flow cytometry: Cell surface antigens.
• PCR/RT-PCR: Gene amplification.
• Blotting (Northern/Southern): Nucleic acid analysis.
• Microarray: Gene expression profiles.
• Recombinant DNA: Produces proteins (e.g., BMP-2, IL-6 inhibitors).
• Immunohistochemistry, ELISA, Western blot: Protein detection/quantification

Immunology

• Innate immunity: Fast, nonspecific.
• Adaptive immunity: Antigen-specific, memory formation.
• Humoral: B-cell mediated.
• Cellular: T-cell mediated.
• Inflammation in connective tissue → osteoclastogenesis → bone resorption

Stem Cells

• Adult stem cells: Self-renewal & tissue repair.
• Mesenchymal stem cells: Differentiate into bone, cartilage.
• Embryonic stem cells: Pluripotent, rejection risk.
• Induced pluripotent stem cells: Reprogrammed somatic cells with pluripotency

Organelle Function Clinical Relevance   

Nucleus Stores DNA Cancer karyotyping, mitotic abnormalities   

Nucleolus Ribosome synthesis Bloom, Treacher Collins, Rothmund-Thomson  

Mitochondria ATP production Neuromuscular disease, diabetes, deafness   

Lysosome Waste degradation Tay-Sachs, Gaucher, Niemann-Pick   

Golgi Apparatus Protein packaging Secretion disorders   

Endoplasmic Reticulum Protein/lipid synthesis Liver & muscle diseases   

Ribosomes Protein synthesis Ribosomopathies, macrocytic anemia   

Cytoskeleton Shape & motility Cardiomyopathy, hearing loss

References

• Valls AF, et al. Nat Rev Mol Cell Biol. 2022.
• Krajnik B, et al. Front Cell Dev Biol. 2020.
• Levoin N, et al. Front Cell Dev Biol. 2020.
• Meng F, et al. Trends Cell Biol. 20241. Cellular and Molecular Biolo…