Week 31 – Chemistry & Cells: Comprehensive Lecture Notes

Course Administration and Expectations

• Week 31 focus: “Chemistry & Cells”.
• Tertiary study is a privilege; disrupting peers’ learning can lead to removal from class.
• Programme has a wait-list → places are valuable; treat sessions seriously.
• Attendance & punctuality required for all tutorials, labs, Monday 511 lectures.
• Computers for tests use Moodle login; verify credentials on any Hub computer before test day to avoid slow start‐up (agreeing to terms of service, etc.).
• Marking window for 135 assignments: 15 working days; resits offered ≈ 2 weeks after marks returned (only 1 resit date).

Upcoming Assessments & Key Dates

• Test 1 and Test 3 = conducted during Monday lecture slot.
  • Start time: 03 : 30 PM — arrive early, decompress, bathroom/snack break.
• Test 3 provisional date: Friday 21 Nov (likely afternoon).
• Labs are at capacity; no backup sessions. Missing a lab → forfeits that learning opportunity.

Laboratory Safety & Dress Code

• Labs differ from tutorials: scalpels, chemicals, dissection tools → higher risk.
• Must read Lab Safety Rules on Moodle before attendance.
• Clothing:
  • No nursing uniforms (staining risk from dyes e.g. methylene blue).
  • Closed shoes only: no open toes, Crocs, jandals, sandals.
• Late arrival after safety briefing = denied entry.
• Specific chemicals next week: methylene blue (permanent blue stain).
• Saline solutions used:
  • Isotonic $0.9\%$ NaCl (matches blood tonicity).
  • Hypertonic $3\%$ NaCl will be discussed (rarely used clinically).

Why Chemistry Matters in Nursing

• Underpins patient care, safety & physiological understanding.
• Critical for:
  • Medication management & dosage calculations (granular errors can be fatal, e.g. fentanyl measured in µg).
  • Pharmacokinetics (movement through body) & pharmacodynamics (interaction with cells).
  • Drug interactions (example: methotrexate ✕ omeprazole unsafe; methotrexate ✓ ondansetron safe).
  • Maintaining homeostasis: electrolytes, acid–base, glucose, IV therapy.
  • Toxicology, infection control, radiology, targeted radiation therapy.

States of Matter & Energy in the Body

• Nurses mainly handle 3 states: solids, liquids, gases (plasma mentioned for completeness).
• Blood centrifugation demo: layers → RBCs, “buffy coat” (WBCs), plasma.
• Energy currency: ATP derived primarily from food; Total Parenteral Nutrition (TPN) substitutes when GI tract unusable.
• Clinical links:
  • Metabolic disorders (e.g. type 2 diabetes, malnutrition).
  • Temperature regulation ↔ energy demand.
  • Wound healing and rehabilitation depend on adequate nutrients.

Atoms, Ions, Elements & Electrolytes

• Key body ions: $\text{Na}^+$, $\text{K}^+$, $\text{H}^+$, $\text{Cl}^-$, $\text{Ca}^{2+}$, $\text{Mg}^{2+}$.
• Imbalances affect nerve/muscle function (e.g. hyponatraemia → confusion, headache, weak muscle contraction including cardiac).
• Supplements: good electrolyte mix = mostly sodium, some potassium, small magnesium.
• Drug molecules = specific atomic arrangements; minor structural change can turn therapeutic drug into illicit substance (ADHD med vs methamphetamine).

Homeostasis, Acid–Base & Lab Values

• Vital to monitor blood values (Na⁺, K⁺, pH, HCO₃⁻, glucose).
• Nurses expected (by Week 2 of 524) to interpret acid–base status from 3 numbers (pH, $\text{PaCO}<em>2$, $\text{HCO}</em>3^-$).
• Conditions:
  • Respiratory acidosis/alkalosis (common in NZ winters post-COVID).
  • Diabetic ketoacidosis (DKA) in Type 1 & 2 diabetics.

Nutrition & Macronutrients

• Balanced intake of carbohydrates (primary energy), lipids (often maligned), proteins (for tissues/enzymes).
• Rapid carbs (jelly) give short spike → crash; complex carbs (rice) sustain energy.
• Re-feeding syndrome danger in malnourished patients; needs gradual caloric/electrolyte restoration.
• Keto diet: designed for epilepsy (glucose deprivation) – unsustainable weight loss side-effect.

Cell Structure (preview)

• Core organelles to review: nucleus, mitochondria, ribosomes, ER, Golgi, lysosomes, cytoskeleton, centrioles, cell membrane.
• Mitosis & tissues covered next week; meiosis included for reproductive relevance.

Cell Membrane Transport Mechanisms

• Classification by ATP requirement and substance type (water vs solute).
• Passive (no ATP):
  • Simple diffusion — small, non-polar molecules move down gradient.
  • Facilitated diffusion — larger/charged particles via carrier or channel proteins.
  • Osmosis — water moves from low solute/high water → high solute/low water through semipermeable membrane.
• Active (requires ATP):
  • Primary active transport (e.g. $\text{Na}^+ / \text{K}^+$ pump, $3\,\text{Na}^+$ out : $2\,\text{K}^+$ in : $1\,\text{ATP}$).
  • Secondary active transport (coupled transport using ion gradients).
  • Bulk transport: endocytosis (phago-/pino-/receptor-mediated), exocytosis.
• Clinically observable examples:
  • Peripheral oedema ↔ osmosis.
  • Glucose uptake via GLUT transporters (facilitated diffusion).
  • Acid pump inhibitors (omeprazole) target $\text{H}^+/\text{K}^+$ ATPase in stomach.

Imaging & Radiation Considerations

• X-ray, CT (ionising radiation), MRI (magnetic), targeted radiotherapy.
• Goal: destroy tumour cells before harming patient — dosage & timing critical (chemistry & physics knowledge needed).

Ethical & Professional Implications

• Patient safety overrides convenience; denying lab entry if unsafe attire is ethical obligation.
• Polypharmacy vigilance: professional duty to cross-check interactions (e.g. via drugs.com, medsache booklet).
• Informed consent paramount (e.g. blood labs, finger-prick glucose tests, centrifuging samples).

Study Resources & Tips

• Moodle News Forum: set to “No digest” → receive announcements immediately (avoid 24 h delay of daily digest).
• Course e-textbook (Pearson): screenshot‐enabled for personal notes; avoid public posting (copyright).
• Useful shortcut: Windows “Ctrl + Shift + S” to snip diagrams for study.
• Practice identifying transport types from unlabeled diagrams; pay attention to arrows and concentration gradients.
• Volunteers needed in tutorials for role-play (cell components skit) — participation aids memory.

Quick Reference Equations & Values

• Isotonic saline: $0.9\%\;\text{NaCl}$.
• Hypertonic saline: $3\%\;\text{NaCl}$.
• $\text{Na}^+$ normal serum: $135 – 145\,\text{mmol·L}^{-1}$.
• $\text{K}^+$ normal serum: $3.5 – 5.0\,\text{mmol·L}^{-1}$.
• Blood pH normal: $7.35 – 7.45$.
• ATP hydrolysis: $\text{ATP} + \text{H}<em>2\text{O} \rightarrow \text{ADP} + \text{P}</em>i + 7.3\,\text{kcal·mol}^{-1}$ (energy released drives active transport).