Long Answer Questions: 1. Explain the structure and functions of mitochondria. Enumerate common mitochondrial disorders and mention their key clinical features. 2. Explain the structure and functions of lysosomes. Add a note on lysosomal storage disorders. 3. Describe the fluid mosaic model of biological membranes. Add a labelled diagram. 4. Classify membrane transport mechanisms. Describe any two with examples. 5. Define carbohydrates. Classify with suitable examples. Add a note on glycosaminoglycans. 6. Classify amino acids on the basis of nutritional and metabolic significance. Add a note on functions of biologically important peptides. 7. Define proteins. Write in detail structural organization of proteins. Add a note on disorders associated with misfolded proteins. 8. Describe the functions of plasma proteins. Add a note on clinical significance of acute phase proteins. 9. Describe the structure of immunoglobulin. Classify immunoglobulins along with their functions. Explain paraproteinemias in brief. 10. Define lipids. Classify with suitable examples. Add a note on functions and clinical significance of phospholipids. Please give me full detailed answer with flowchart and images with mbbs exam oriented answer
QUICK REFERENCE SUMMARY TABLE
| Q# | Topic | Key Exam Points |
|---|---|---|
| 1 | Mitochondria | Double membrane; Cristae = ATP synthase; mtDNA = circular, maternal; MELAS/MERRF/KSS/Leigh; Ragged red fibers on Gomori |
| 2 | Lysosomes | Acid hydrolases; pH 4.5-5; M6P targeting; Gaucher = most common LSD; Cherry red spot in Tay-Sachs/Niemann-Pick; I-cell disease = M6P defect |
| 3 | Fluid Mosaic Model | Singer & Nicolson 1972; Lateral diffusion fast, flip-flop slow; Cholesterol = fluidity buffer; Asymmetry (PS inner leaflet); Lipid rafts |
| 4 | Membrane Transport | Simple → Facilitated → Active (Primary: Na/K ATPase; Secondary: SGLT1) → Vesicular; Na/K ATPase = 3Na out:2K in:1ATP; LDL receptor endocytosis |
| 5 | Carbohydrates | Formula Cₙ(H₂O)ₙ; Mono→Di→Oligo→Poly; Glycogen (animal) vs Starch (plant); GAGs = repeating disaccharides; Hyaluronic acid = not sulfated; Heparin = most sulfated |
| 6 | Amino Acids | EAA = "PVT TIM HaLL"; Purely ketogenic = Leu + Lys; Glutathione = γ-Glu-Cys-Gly (antioxidant); Oxytocin, ADH = nonapeptides |
| 7 | Proteins | 4 levels: Primary (peptide bonds) → Secondary (H-bonds: α-helix, β-sheet) → Tertiary (hydrophobic+ionic+VdW+S-S) → Quaternary (multi-subunit); Congo red = amyloid; Prion = infectious misfolded protein |
| 8 | Plasma Proteins | Albumin 4-5.5g/dL (80% oncotic pressure); Positive APP: CRP rises 1000-fold; Negative APP: Albumin, Transferrin, Prealbumin; IL-6 = main inducer |
| 9 | Immunoglobulins | IgG = most abundant, crosses placenta, longest t½; IgM = pentamer, first responder, best complement activator; IgA = mucosal immunity; IgE = allergy; Paraproteinemia: M-spike on SPE; Multiple myeloma = CRAB |
| 10 | Lipids | Simple/Compound/Derived; Phospholipids = amphipathic; DPPC = lung surfactant; L/S ≥2 = mature; PS externalization = apoptosis; APS = anticardiolipin antibodies; PAF = potent inflammatory mediator |
References: Guyton & Hall Medical Physiology; Junqueira's Basic Histology; Robbins & Kumar Basic Pathology; Ganong's Review of Medical Physiology; Histology: A Text and Atlas (Pawlina); Basic Medical Biochemistry (Marks); Harrison's Principles of Internal Medicine 22E; Roitt's Essential Immunology