100 QUESTIONS AND ANSWERS RELATED TO THE BIOCHEMICAL BASIS OF DISEASES

 

The following are 100 questions and answers in biochemistry of diseases:

 

1. What is the biochemical basis of diseases?

The biochemical basis of diseases refers to the molecular and cellular changes that occur at the biochemical level, leading to the development and progression of various diseases.

 

2. How do genetic mutations contribute to diseases?

Genetic mutations can alter the structure and function of proteins, enzymes, and other molecules, leading to dysfunctional biochemical pathways that can cause diseases.

 

3. What role does oxidative stress play in diseases?

Oxidative stress, caused by an imbalance between reactive oxygen species and antioxidant defenses, can damage cellular components and contribute to various diseases, including neurodegenerative disorders and cancer.

 

4. How does diabetes mellitus affect carbohydrate metabolism?

Diabetes mellitus disrupts glucose metabolism, resulting in elevated blood sugar levels due to insufficient insulin action or production.

 

5. What is the role of cholesterol in cardiovascular diseases?

High cholesterol levels can lead to the formation of atherosclerotic plaques in blood vessels, contributing to cardiovascular diseases like heart attacks and strokes.

 

6. How do enzyme deficiencies cause metabolic disorders?

Enzyme deficiencies disrupt biochemical pathways, leading to the accumulation of toxic intermediates and causing metabolic disorders like phenylketonuria (PKU) or Gaucher's disease.

 

7. What is the Warburg effect, and how does it relate to cancer?

The Warburg effect is the observation that cancer cells often rely on glycolysis for energy even in the presence of oxygen. This phenomenon is thought to support the rapid growth of cancer cells.

 

8. How does sickle cell anemia result from a single amino acid substitution?

Sickle cell anemia results from a genetic mutation that causes a single amino acid substitution in hemoglobin, leading to the characteristic sickle-shaped red blood cells and impaired oxygen transport.

 

9. What is protein misfolding, and how does it contribute to diseases like Alzheimer's?

Protein misfolding occurs when proteins adopt an incorrect three-dimensional structure, leading to aggregation and deposition in tissues, as seen in neurodegenerative diseases like Alzheimer's.

 

10. How does mitochondrial dysfunction contribute to neurodegenerative diseases?

Mitochondrial dysfunction impairs energy production and can lead to oxidative stress, contributing to the progression of neurodegenerative diseases like Parkinson's and Alzheimer's.

 

11. What role do prions play in causing diseases?

Prions are misfolded proteins that can induce the misfolding of normal proteins, leading to the development of diseases like Creutzfeldt-Jakob disease and mad cow disease.

 

12. How do autoimmune diseases arise from immune system dysfunction?

Autoimmune diseases result from the immune system mistakenly attacking the body's own cells and tissues due to a breakdown in self-tolerance mechanisms.

 

13. What is the role of inflammation in chronic diseases?

Chronic inflammation can contribute to the development of diseases like atherosclerosis, diabetes, and cancer by promoting tissue damage and dysfunction.

 

14. How does insulin resistance lead to type 2 diabetes?

Insulin resistance occurs when cells become less responsive to insulin, leading to elevated blood sugar levels and eventually causing type 2 diabetes.

 

15. What is the link between obesity and metabolic syndrome?

Obesity is a major risk factor for metabolic syndrome, a cluster of conditions including high blood pressure, high blood sugar, and abnormal lipid levels, which increase the risk of cardiovascular diseases.

 

16. How do lysosomal storage diseases occur?

Lysosomal storage diseases result from the accumulation of undegraded substrates within lysosomes due to deficiencies in specific enzymes required for their breakdown.

 

17. What is the role of amyloid plaques in Alzheimer's disease?

Amyloid plaques, composed of misfolded amyloid-beta proteins, accumulate in the brains of Alzheimer's patients and are associated with neuronal damage and cognitive decline.

 

18. How does the malfunction of ion channels lead to channelopathies?

Channelopathies are diseases caused by dysfunction in ion channels, disrupting the normal flow of ions across cell membranes and leading to various disorders like cystic fibrosis and Long QT syndrome.

 

19. What is the biochemical basis of phenylketonuria (PKU)?

PKU is caused by a deficiency of the enzyme phenylalanine hydroxylase, leading to the accumulation of phenylalanine, which can cause intellectual disabilities if not managed.

 

20. How does Huntington's disease involve CAG trinucleotide repeats?

Huntington's disease is caused by the expansion of CAG trinucleotide repeats in the huntingtin gene, resulting in the production of a mutant protein that forms aggregates in the brain.

 

21. How do mutations in the BRCA genes increase the risk of breast cancer?

Mutations in BRCA1 and BRCA2 genes impair DNA repair mechanisms, increasing the susceptibility to DNA damage and contributing to the development of breast and ovarian cancers.

 

22. What is the role of inflammation in rheumatoid arthritis?

In rheumatoid arthritis, an autoimmune response leads to chronic inflammation in the joints, causing pain, swelling, and tissue damage.

 

23. How does the abnormal hemoglobin structure cause thalassemia?

Thalassemia results from mutations that affect the production of hemoglobin subunits, leading to an imbalance in alpha and beta globin chains and causing anemia.

 

24. What are the biochemical mechanisms underlying cystic fibrosis?

Cystic fibrosis is caused by mutations in the CFTR gene, leading to defective chloride ion transport and the production of thick, sticky mucus that affects the lungs and other organs.

 

25. How does G6PD deficiency lead to hemolytic anemia?

G6PD deficiency impairs the antioxidant defense system of red blood cells, making them more susceptible to oxidative stress and causing hemolytic anemia.

 

26. What is the connection between hyperlipidemia and atherosclerosis?

Hyperlipidemia, characterized by elevated levels of lipids in the blood, contributes to the formation of atherosclerotic plaques in blood vessels, increasing the risk of cardiovascular diseases.

 

27. How does alcohol metabolism contribute to alcoholic liver disease?

Alcohol metabolism produces toxic byproducts that can damage liver cells, leading to alcoholic liver disease, including fatty liver, alcoholic hepatitis, and cirrhosis.

 

28. What is the role of prion proteins in prion diseases?

Prion proteins can spontaneously convert into abnormal conformations, triggering a chain reaction of misfolding and aggregation that leads to prion diseases.

 

29. How does the loss of dopamine-producing neurons cause Parkinson's disease?

Parkinson's disease results from the degeneration of dopamine-producing neurons in the substantia nigra, leading to movement disorders due to dopamine deficiency.

 

30. What is the role of amylin in diabetes management?

Amylin is a hormone co-secreted with insulin by pancreatic beta cells, regulating glucose levels by slowing down gastric emptying and suppressing glucagon secretion.

 

31. How does hyperglycemia contribute to diabetic complications?

Hyperglycemia damages blood vessels and tissues by promoting oxidative stress, inflammation, and the formation of advanced glycation end products, leading to diabetic complications.

 

32. How does the dysfunction of the ubiquitin-proteasome system contribute to neurodegenerative diseases?

The dysfunction of the ubiquitin-proteasome system leads to the accumulation of misfolded proteins in neurodegenerative diseases like Parkinson's and Alzheimer's.

 

33. What is the role of myelin in multiple sclerosis?

Multiple sclerosis is characterized by the immune system attacking and damaging the myelin sheath, disrupting nerve signal transmission and causing neurological symptoms.

 

34. How does DNA methylation contribute to epigenetic regulation in cancer?

Aberrant DNA methylation patterns can silence tumor suppressor genes and activate oncogenes, contributing to the development and progression of cancer.

 

35. How does the abnormal expansion of trinucleotide repeats lead to myotonic dystrophy?

Myotonic dystrophy is caused by the expansion of CTG trinucleotide repeats in the DMPK gene, resulting in RNA toxicity and affecting muscle function.

 

36. What is the role of telomeres in cellular aging and cancer?

Telomeres protect the ends of chromosomes from degradation and fusion. Shortened telomeres are associated with cellular aging, while their maintenance is crucial for avoiding uncontrolled cell division seen in cancer.

 

37. How does HIV/AIDS affect the immune system?

HIV targets CD4+ T cells, leading to their depletion and weakening the immune response, ultimately resulting in acquired immunodeficiency syndrome (AIDS).

 

38. What is the role of amyloid-beta in Alzheimer's disease progression?

Amyloid-beta aggregates form plaques in the brains of Alzheimer's patients, contributing to neuronal dysfunction, inflammation, and cognitive decline.

 

39. How does the dysregulation of insulin signaling contribute to insulin resistance?

Dysregulation of insulin signaling pathways can lead to reduced glucose uptake by cells, contributing to insulin resistance and the development of type 2 diabetes.

 

40. What is the biochemical basis of porphyria?

Porphyria is a group of rare genetic disorders involving defects in heme biosynthesis, leading to the accumulation of porphyrins, which can cause neurological and other symptoms.

 

41. How do mutations in ion channels cause epilepsy?

Mutations in ion channels can lead to abnormal neuronal excitability and synchronization, resulting in epileptic seizures.

 

42. How does alpha-synuclein aggregation contribute to Parkinson's disease?

Aggregated alpha-synuclein forms Lewy bodies, which are pathological hallmarks of Parkinson's disease, and their accumulation contributes to neuronal dysfunction and death.

 

43. What is the role of the unfolded protein response in cellular stress?

The unfolded protein response is activated in response to protein misfolding and stress in the endoplasmic reticulum, aiming to restore cellular homeostasis or induce apoptosis.

 

44. How does chronic alcohol consumption lead to Wernicke-Korsakoff syndrome?

Chronic alcohol consumption can lead to thiamine (vitamin B1) deficiency, which contributes to the development of Wernicke-Korsakoff syndrome, characterized by neurological and memory deficits.

 

45. How does p53 function as a tumor suppressor gene?

p53 plays a crucial role in DNA damage response and cell cycle regulation. Mutations in p53 can lead to uncontrolled cell division and contribute to cancer development.

 

46. What is the role of B-cell dysfunction in autoimmune diseases like lupus?

B-cell dysfunction and the production of autoantibodies play a role in autoimmune diseases like systemic lupus erythematosus (SLE), leading to tissue damage and inflammation.

 

47. How does the malfunction of the LDL receptor lead to familial hypercholesterolemia?

Familial hypercholesterolemia is caused by mutations in the LDL receptor gene, leading to impaired uptake of LDL cholesterol and increased risk of cardiovascular diseases.

 

48. How does hemoglobin S lead to vaso-occlusive crises in sickle cell disease?

Hemoglobin S in sickle cell disease polymerizes under low oxygen conditions, causing red blood cells to assume a sickle shape, leading to vaso-occlusive crises and tissue damage.

 

49. How do mutations in the CFTR gene cause cystic fibrosis?

Mutations in the CFTR gene disrupt the function of chloride channels, leading to thick and sticky mucus production that affects various organs in cystic fibrosis.

 

50. What is the biochemical basis of Alzheimer's disease-related tau pathology?

Tau protein aggregates in the form of neurofibrillary tangles are a hallmark of Alzheimer's disease, disrupting neuronal function and contributing to cognitive decline.

 

 51. How does the dysfunction of the von Willebrand factor lead to von Willebrand disease?

Von Willebrand disease is characterized by a deficiency or dysfunction of the von Willebrand factor, impairing platelet adhesion and leading to bleeding disorders.

 

52. What is the role of the immune system in multiple sclerosis?

In multiple sclerosis, the immune system attacks the myelin sheath around nerve fibers, leading to demyelination and neurological symptoms.

 

53. How do epigenetic modifications contribute to cancer development?

Epigenetic modifications, such as DNA methylation and histone modifications, can alter gene expression patterns in ways that promote cancer progression.

 

54. How does the dysregulation of the renin-angiotensin-aldosterone system contribute to hypertension?

Dysregulation of the renin-angiotensin-aldosterone system can lead to elevated blood pressure, contributing to hypertension and its associated complications.

 

55. What is the role of glutamate excitotoxicity in neurodegenerative diseases?

Glutamate excitotoxicity refers to the excessive release of glutamate, which can lead to neuronal damage and death, contributing to neurodegenerative diseases like ALS and Huntington's.

 

56. How does celiac disease involve gluten intolerance and autoimmune reactions?

Celiac disease is an autoimmune disorder triggered by the ingestion of gluten, leading to an immune response that damages the lining of the small intestine.

 

57. What is the biochemical basis of Wilson's disease?

Wilson's disease is caused by a genetic mutation that impairs copper transport, leading to copper accumulation in the liver and other tissues, causing various symptoms.

 

58. How do defects in the ABC transporters contribute to diseases like cystic fibrosis and Tangier disease?

Defects in ABC transporters, which play a role in transporting lipids and other molecules across cell membranes, can lead to diseases like cystic fibrosis and Tangier disease.

 

59. How does the JAK-STAT signaling pathway contribute to autoimmune diseases?

The JAK-STAT pathway is involved in immune cell activation and cytokine signaling. Dysregulation of this pathway can contribute to autoimmune diseases like rheumatoid arthritis.

 

60. How does the loss of functional dystrophin lead to muscular dystrophy?

Dystrophin is essential for maintaining the integrity of muscle fibers. Its absence leads to muscular dystrophy, characterized by progressive muscle weakness and degeneration.

 

61. What is the role of amyloid precursor protein (APP) in Alzheimer's disease?

APP is cleaved to produce amyloid-beta peptides, which can aggregate and form plaques in Alzheimer's disease, contributing to neurodegeneration.

 

 

 

62. How does the imbalance of neurotransmitters contribute to mood disorders like depression?

Imbalances in neurotransmitters like serotonin, dopamine, and norepinephrine are associated with mood disorders like depression and bipolar disorder.

 

63. What is the role of cAMP signaling in hormonal regulation?

cAMP is a secondary messenger that plays a role in transmitting hormonal signals in various cellular processes, including metabolism and gene expression.

 

64. How does the disruption of autophagy contribute to neurodegenerative diseases?

Autophagy is involved in clearing damaged cellular components. Its dysfunction can lead to the accumulation of protein aggregates seen in neurodegenerative diseases.

 

65. How do mutations in the CFTR gene lead to cystic fibrosis?

Mutations in the CFTR gene lead to impaired chloride ion transport and water balance, resulting in the production of thick mucus that affects the respiratory and digestive systems in cystic fibrosis.

 

66. What is the role of the BRCA genes in DNA repair and cancer susceptibility?

BRCA1 and BRCA2 are involved in DNA repair mechanisms. Mutations in these genes increase the risk of breast and ovarian cancers due to impaired DNA damage response.

 

67. How does chronic inflammation contribute to colorectal cancer?

Chronic inflammation, often caused by conditions like inflammatory bowel disease, can promote genetic mutations and cellular changes that lead to the development of colorectal cancer.

 

68. What is the biochemical basis of Gout?

Gout is caused by the accumulation of uric acid crystals in joints, leading to inflammation and pain. It results from the overproduction or under-excretion of uric acid.

 

69. How do defects in DNA repair mechanisms lead to cancer susceptibility?

Defects in DNA repair pathways increase the risk of cancer, as accumulated DNA damage can result in mutations and genomic instability.

 

70. How does abnormal calcium homeostasis contribute to neurodegenerative diseases?

Dysregulation of calcium homeostasis can lead to excitotoxicity and neuronal damage, contributing to neurodegenerative diseases like Alzheimer's and Parkinson's.

 

71. What is the biochemical basis of osteoporosis?

Osteoporosis is characterized by reduced bone density due to an imbalance between bone resorption and formation, often linked to hormonal changes and aging.

 

72. How do mutations in the FMR1 gene lead to fragile X syndrome?

Fragile X syndrome is caused by a CGG trinucleotide repeat expansion in the FMR1 gene, leading to a lack of functional fragile X mental retardation protein (FMRP) and cognitive impairment.

 

73. How does the unfolded protein response contribute to endoplasmic reticulum stress-related diseases?

The unfolded protein response is activated when misfolded proteins accumulate in the endoplasmic reticulum, aiming to restore protein-folding homeostasis. Dysregulation can contribute to various diseases.

 

74. What is the biochemical basis of Pompe disease?

Pompe disease results from a deficiency of the enzyme acid alpha-glucosidase, leading to the accumulation of glycogen in lysosomes and causing muscle weakness.

 

75. How does aberrant DNA methylation contribute to cancer progression?

Aberrant DNA methylation can lead to the silencing of tumor suppressor genes and the activation of oncogenes, promoting cancer development and progression.

 

76. What is the role of the HIF-1 pathway in hypoxic conditions and cancer?

The HIF-1 pathway is activated in response to low oxygen levels (hypoxia) and can promote the survival of cancer cells by inducing the expression of genes involved in angiogenesis and metabolism.

 

77. How does the deficiency of sphingomyelinase lead to Niemann-Pick disease?

Niemann-Pick disease is caused by a deficiency of sphingomyelinase, leading to the accumulation of sphingomyelin in lysosomes, resulting in neurological and visceral symptoms.

 

78. How does insulin resistance contribute to the development of polycystic ovary syndrome (PCOS)?

Insulin resistance can lead to hormonal imbalances that contribute to the development of PCOS, characterized by irregular menstrual cycles, excessive hair growth, and ovarian cysts.

 

79. What is the biochemical basis of galactosemia?

Galactosemia results from the deficiency of enzymes involved in galactose metabolism, leading to the accumulation of toxic galactose metabolites.

 

80. How do mutations in the BLM gene lead to Bloom syndrome?

Bloom syndrome is caused by mutations in the BLM gene, leading to defective DNA repair mechanisms and genomic instability, resulting in a predisposition to cancer and other symptoms.

 

81. What is the role of glutathione in protecting cells from oxidative stress?

Glutathione is a key antioxidant molecule that helps neutralize reactive oxygen species and protect cells from oxidative damage.

 

82. How does chronic hepatitis B infection contribute to liver cancer development?

Chronic hepatitis B infection can lead to persistent liver inflammation and DNA damage, increasing the risk of liver cancer (hepatocellular carcinoma).

 

83. What is the role of mTOR signaling in cancer and aging?

mTOR signaling regulates cell growth, metabolism, and autophagy. Dysregulation of this pathway is implicated in cancer development and aging-related processes.

 

84. How does the mutation in the CFTR gene affect the chloride channel function in cystic fibrosis?

Mutations in the CFTR gene can result in a defective chloride channel, impairing the movement of chloride ions and affecting fluid balance in various organs.

 

85. What is the biochemical basis of phenylalanine hydroxylase deficiency in PKU?

Phenylalanine hydroxylase deficiency in PKU leads to the accumulation of phenylalanine, which can cause intellectual disabilities and other neurological symptoms.

 

86. How does the loss of retinal cells lead to retinitis pigmentosa?

Retinitis pigmentosa is characterized by the progressive degeneration of retinal cells, leading to vision loss due to impaired photoreceptor function.

 

87. What is the role of the TGF-beta signaling pathway in fibrosis?

The TGF-beta signaling pathway plays a role in tissue repair and fibrosis. Dysregulation can lead to excessive collagen deposition and tissue scarring.

 

88. How do oncogenic mutations in the Ras pathway contribute to cancer?

Oncogenic mutations in the Ras pathway can lead to uncontrolled cell growth and division, contributing to the development of various types of cancer.

 

89. What is the role of alpha-1 antitrypsin deficiency in emphysema?

Alpha-1 antitrypsin deficiency impairs the protection of lung tissue from the damaging effects of proteases, contributing to emphysema development.

 

90. How does the mutation in the CYP27B1 gene lead to vitamin D-dependent rickets type 1?

Mutations in the CYP27B1 gene impair the conversion of inactive vitamin D to its active form, leading to calcium and phosphate imbalances and causing rickets.

 

91. What is the biochemical basis of Gaucher's disease?

Gaucher's disease is caused by a deficiency of the enzyme glucocerebrosidase, leading to the accumulation of glucocerebroside in lysosomes, causing various symptoms.

 

92. How do mutations in the LDL receptor lead to familial hypercholesterolemia?

Mutations in the LDL receptor gene impair the uptake of LDL cholesterol from the blood, leading to elevated cholesterol levels and increased cardiovascular risk.

 

93. What is the role of the P53 gene in cancer suppression?

P53 is a tumor suppressor gene that plays a crucial role in cell cycle regulation, DNA repair, and apoptosis. Mutations in P53 are associated with increased cancer risk.

 

94. How does the imbalance of neurotransmitters contribute to schizophrenia?

The imbalance of neurotransmitters like dopamine and glutamate is thought to play a role in the development of schizophrenia and its associated cognitive and behavioral symptoms.

 

95. What is the role of the EGF receptor in cancer progression?

The epidermal growth factor (EGF) receptor is often overexpressed or mutated in cancer, leading to uncontrolled cell growth and contributing to cancer progression.

 

96. How does dysregulation of the Wnt signaling pathway contribute to cancer?

Dysregulation of the Wnt signaling pathway can lead to uncontrolled cell proliferation and migration, promoting cancer development and metastasis.

 

97. What is the biochemical basis of Alkaptonuria?

Alkaptonuria results from the deficiency of the enzyme homogentisate 1,2-dioxygenase, leading to the accumulation of homogentisic acid, causing darkening of urine and joint problems.

 

98. How does the dysfunction of neurotransmitter systems contribute to neurodegenerative diseases like ALS?

The dysfunction of neurotransmitter systems, including glutamate and GABA, can lead to neuronal excitotoxicity and contribute to the development of neurodegenerative diseases like ALS.

 

99. What is the role of epigenetics in the development of asthma and allergies?

Epigenetic modifications can influence gene expression related to immune responses, contributing to the development of asthma and allergies.

 

100. How does the dysregulation of the MAPK pathway contribute to cancer?

Dysregulation of the MAPK pathway can lead to uncontrolled cell growth and division, contributing to cancer development and progression.

 

Kindly note that the above answers are concise, general explanations and may not cover all possible details (they are direct responses to the questions in biochemistry viva questions), more details may be needed in examination scenario. Hence, it’s recommended to refer to textbooks for further details.

Best of luck.

 

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