NURS 1110: Biochemistry Lecture 2

Course Information

• NURS 1110: Biochemistry, Lecture 2 - Cell Function DNA/RNA
• Instructor: Andrew S. Dhanoo, BSc., RPT, PhD. (candidate)
• Contact information: [email protected]
• Textbook: Handbook of Applied Biochemistry, Nutrition and Dietetics for Nursing and Allied Health Students by Shivananda Nayak B

Course Outline

• Credits: 3
• Class schedule: Friday, 8 am - 12 noon (ZOOM)
• Course delivery: Lectures, with in-class demonstrations
• Course assessment:
  • In-course exams: 25%
  • Group project: 15%
  • Final exam: 60%

Group Project

• Submissions:
  • Project outline (3%): 1 page with title, introduction, body, and conclusion (week 6)
  • 3MT style video (6%): 3-minute video presentation (week 11)
  • Academic poster (6%): 750-1000 words (week 12)
  • Participation: out of 10 and multiplied by group mark
• Group formation: 5-6 members
• Recommendations:
  • Meet weekly
  • Form an online network for easy communication (e.g., WhatsApp group)
  • Assign roles to each member
  • Assign deadlines

Group Project Topics

• 1. Diabetes Mellitus: How does double diabetes develop?
• 2. Prader Willi Syndrome: Genetic imprinting and chromosome 15q deletion
• 3. Breast Cancer: BRCA gene mutation
• 4. HIV Infection: Mechanism of viral entry, reverse transcription, and replication
• 5. Cushing Disease: Cortisol, adrenal tumors, and hormone regulation
• 6. Graves' Disease: Autoimmune thyroid dysfunction and hormone production
• 7. Klinefelter's Syndrome: XXY karyotype, hormones, and development
• 8. Galactosemia: Galactose metabolism, enzyme defects, and toxicity
• 9. Wilson's Disease: Copper metabolism and ATP7B gene mutations
• 10. COVID-19 Cytokine Storm: Cytokines, inflammation, and severe COVID-19 cases
• 11. Arsenic Poisoning: Mechanisms of arsenic toxicity and enzyme interference
• 12. Paraquat Toxicity in Humans: Oxidative stress and mitochondrial damage
• 13. Parkinson's Disease: Alpha-synuclein, dopamine, and mitochondrial dysfunction
• 14. Ivermectin Action: Neurotransmission in parasites and anti-parasitic use
• 15. Alzheimer's Disease: Amyloid beta and tau protein pathology
• 16. Sickle Cell Anemia: Hemoglobin structure and function
• 17. Huntington's Disease: CAG repeat expansion and protein aggregation
• 18. Multiple Sclerosis: Autoimmune attack on myelin
• 19. Cystic Fibrosis: CFTR gene mutations and ion transport
• 20. Hemochromatosis: Iron overload and HFE gene mutations
• 21. G6PD Deficiency: Glucose-6-phosphate dehydrogenase enzyme and red blood cell breakdown
• 22. Phenylalanine Hydroxylase Deficiency: Biochemistry of phenylalanine metabolism
• 23. Tay-Sachs Disease: Hexosaminidase A deficiency and ganglioside accumulation
• 24. Amyotrophic Lateral Sclerosis (ALS): Protein misfolding and aggregation
• 25. Hemophilia: Blood clotting and deficiency of clotting factors and genetic basis

Cell Function

• Functional features:
  • Cell development
  • DNA and RNA replication, repair, and translation
  • Transport mechanisms
  • Delivery and removal of substances
  • Respiration

Cell Development

• Mitosis: somatic cell division, cell growth, and reproduction
• Meiosis: gametic cell division, reduction in chromosome number, and genetic variation

Cell Cycle

• Interphase: G1, S, and G2 phases
• Mitosis: prophase, metaphase, anaphase, and telophase
• Regulation: checkpoints to ensure accurate cell division

Mitosis

• Prophase: chromatin condenses, spindle fibers form, and nuclear membrane breaks down
• Metaphase: chromosomes align at the equator
• Anaphase: chromosomes separate and move to opposite poles
• Telophase: chromosomes relax, and nuclear envelopes reform
• Cytokinesis: cell division and cytoplasm distribution

Meiosis

• Two rounds of cell division to produce four haploid cells
• Differences between mitosis and meiosis:
  • Number of cell divisions
  • Number of daughter cells
  • Chromosome number
  • Cell type
  • Pairing and crossing over
• Sources of genetic variability:
  • Homologous pairing and crossing over
  • Random alignment of homologous pairs
  • Random sorting of chromosomes into daughter cells

DNA Replication

• Key points:
  • Semi-conservative replication
  • DNA replication occurs in 5' to 3' direction
  • Replication begins at the origin of replication
  • Primers are added to template strands
  • Leading strand synthesis is continuous, while lagging strand synthesis is discontinuous
• Enzymes and proteins involved:
  • Helicase: separates double helix strands
  • Single-stranded binding proteins: stabilize new single strands
  • DNA gyrase: prevents supercoiling
  • DNA polymerase: attaches new nucleotides
  • Beta clamps: hold DNA polymerase in place
  • Primase: attaches primers
  • DNA ligase: ensures fragments are bonded

Protein Synthesis

• Key points:
  • Transcription: DNA is copied into RNA
  • Translation: mRNA is decoded by a ribosome to produce a polypeptide
  • Gene: area of DNA that codes for a protein
  • Locus: specific location of a gene in the DNA
  • Promoter sequence: the start of a gene where transcription begins
  • Termination sequence: the end of a gene where transcription finishes
  • Codon: sequence of 3 bases in mRNA that corresponds to one amino acid
• Transcription:
  • Initiation: gene switched on, RNA polymerase attaches at the promoter region
  • Elongation: free bases are added to form mRNA, complementary to the DNA bases

This quiz assesses understanding of cell function, DNA, and RNA in the context of biochemistry. It is based on Lecture 2 of the NURS 1110 course at the University of the West Indies.