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 deafness1. Cellular and Molecular Biolo…
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⁺.
Control gene expression and cellular responses1. Cellular and Molecular Biolo…
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 expression1.
RNA Biology
mRNA: Protein coding.
miRNA: Gene regulation.
rRNA: Part of ribosome, diagnostic use in bacteria1.
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, phosphorylation1.
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/quantification1. Cellular and Molecular Biolo…
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 resorption1. Cellular and Molecular Biolo…
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 pluripotency1. Cellular and Molecular Biolo…
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
Krajnik A, Brazzo JA 3rd, Vaidyanathan K, Das T, Redondo-Muñoz J, Bae Y. Phosphoinositide Signaling and Mechanotransduction in Cardiovascular Biology and Disease. Front Cell Dev Biol. 2020 Dec 14;8:595849. doi: 10.3389/fcell.2020.595849. PMID: 33381504; PMCID: PMC7767973.
Levoin N, Jean M, Legembre P. CD95 Structure, Aggregation and Cell Signaling. Front Cell Dev Biol. 2020 May 5;8:314. doi: 10.3389/fcell.2020.00314. PMID: 32432115; PMCID: PMC7214685.