CBSE · Class 12 · Biology · Chapter 7

Human Health and Disease — Formula Sheet

Board Formulas

10 formulas

1.Antibody Structure★
$Antibody = H_{2} L_{2} (2 heavy + 2 light chains)$
Y-shaped molecule; each arm has an antigen-binding site (Fab); stem is Fc.
2.Five Classes of Immunoglobulins★
$IgG, IgA, IgM, IgE, IgD$
IgG crosses placenta; IgA in secretions; IgM first responder in primary response; IgE in allergies; IgD B-cell receptor.
3.Types of Immunity
$Innate (non-specific) + Acquired (specific: active/passive)$
Active immunity is slow but long-lasting; passive is fast but short-lived.
4.HIV Genome and Enzyme★
$HIV = ssRNA + reverse transcriptase (RT); RNA RT DNA$
Retrovirus — reverses the central dogma to make DNA from RNA.
5.AIDS Detection Test★
$ELISA (Enzyme-Linked Immunosorbent Assay)$
Detects anti-HIV antibodies in patient's blood; confirmed by Western blot.
6.Cancer Cell Trait★
$Loss of contact inhibition + uncontrolled division + metastasis (malignant)$
Benign tumours stay put; malignant tumours invade and spread through blood/lymph.
7.Cancer Detection Techniques
$Biopsy, histopathology, CT, MRI, PET, tumour-marker antibodies$
Molecular biology techniques detect genes with cancer predisposition.
8.Drug Chemical Formulas
$Morphine (opioid): C_{17} H_{19} NO_{3}; Cocaine: C_{17} H_{21} NO_{4}$
Morphine binds opioid receptors; cocaine blocks dopamine reuptake.
9.Interferon Function
$Virus-infected cell \to Interferon \to Protects neighbouring cells$
Cytokine of the innate immune system; enhances antiviral state.
10.Vaccination Principle
$Antigen (weakened/killed) \to Memory B and T cells \to Rapid secondary response$
Induces active immunity without causing disease.