Molecular basis of diseases Flashcards
What is a disease?
According to the Oxford English Dictionary, a disease is “a condition of the body, or some part or organ of the body, in which its functions are disturbed or deranged.”
What are the main types of diseases?
- Infectious diseases (e.g., tuberculosis, flu, candidiasis, malaria)
- Injuries (e.g., fractures)
- Diseases caused by environmental factors (e.g., silicosis)
- Genetic mutations (e.g., inherited cystic fibrosis, acquired cancer)
- Multifactorial disorders (e.g., heart disease, schizophrenia)
Why is it important to understand the different types of diseases?
It aids in diagnosis, understanding the causes, targeting specific interventions, and developing treatments based on molecular mechanisms.
What is the “Chain of Infection”?
It includes:
- Susceptible Host
- Portals of Entry
- Modes of Transmission
- Pathogens
- Reservoirs
- Portals of Exit
How do viruses infect cells?
Viruses bind to host cells, enter them, and incorporate their genomes into host DNA to replicate, often damaging or killing the host cell in the process.
What are examples of viral infections?
- Influenza virus (Flu)
- SARS-CoV-2 (COVID-19)
- HIV (AIDS)
Describe Gram-positive vs. Gram-negative bacteria.
- Gram-positive: Thick peptidoglycan cell wall with teichoic acid; less resistant to antibiotics.
- Gram-negative: Thin cell wall with an outer membrane; more resistant due to porins and drug pumps.
What is Tuberculosis (TB)?
TB, caused by Mycobacterium tuberculosis, is a bacterial infection primarily affecting the lungs, with over one-third of the world population infected.
What are monogenic disorders?
Diseases caused by mutations in a single gene, such as Familial Hypercholesterolaemia (FH), which is linked to high LDL cholesterol levels and cardiovascular disease.
What causes atherosclerosis in coronary heart disease?
High LDL levels lead to plaque formation in arteries, narrowing them and increasing the risk of blood clots and heart attacks.
What are polygenic disorders, and give an example?
Diseases caused by mutations in multiple genes. For instance, lung cancer is associated with mutations in genes like EGFR, K-Ras, MET, and LKB1.
What are multifactorial diseases?
Diseases influenced by both genetic and environmental factors, such as schizophrenia, diabetes, Alzheimer’s, asthma, and heart disease.
Describe the molecular basis of Type 2 Diabetes (T2D).
T2D involves insulin resistance or insufficient insulin production, often influenced by lifestyle and genetic factors, leading to high blood glucose levels.
What is the link between obesity and T2D?
Excess fat, particularly abdominal, raises free fatty acid levels in the blood, which is linked to insulin resistance and can exacerbate T2D.
Why is it crucial to understand the molecular basis of diseases?
It allows for the identification of drug targets, aiding in the development of treatments that can precisely address underlying molecular dysfunctions.
