CELS191 Introduction and Diversity of Life Notes

CELS191 Course Information

• Course Convenor: Professor Sally McCormick (Academic oversight)
• Course Coordinator: Samantha Campbell (cels191.admin@otago.ac.nz)
• Course Administrator: Dr Lisa Russell (lisa.russell@otago.ac.nz)
• Teaching Fellows: Dr Kim Watson, Mary Wallace, Dr Keith King, Dr Tanya Major, Mia Rickard-Green, Kieran Redpath
• Office: MEG04 Mellor Laboratories
• Phone: +64 3 479 4563
• Contact: Sam for course enquiries or appointments with Lisa

Course Modules

• Module 1: Cell Structure & Diversity
• Module 2: Molecular Biology & Genetics
• Module 3: Human Molecular Genetics
• Module 4: Microbiology

Lectures

• Attendance is expected; recordings are available on Blackboard.
• Core slides indicate examinable content.

Laboratories

• Start date: Next Monday (3 Mar)
• Five compulsory lab rotations in MEG06 Mellor Laboratories.
• Requirements: Closed-toe shoes, lab coat, ID card.
• Duration: 3 hours, every two weeks.

Resources

• Course Information booklet: Available in PDF on Blackboard and printed copies outside MEG06.
• Blackboard: Course resources, links, and information.

Key Concepts from Lecture 1: The Diversity of Life

• Characteristics of Life: Cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth, development, adaptation through evolution.
• Origin of Life: Complex biomolecule generation, RNA world, chelation by mineral clays, panspermia.
• Early Earth: Fossil cells appear by 3.4 billion years ago.
• Scales of Nature:
  • Measured in micrometres (µm) for cells & organelles.
  • Eukaryote cells: 10-100 µm
  • Prokaryote cells: Less than 5 µm
  • Mitochondria: 1-10 µm, chloroplasts 2-5µm
• Evolution: Requires variation, inheritance, selection, and time.
• Natural Selection: Individuals vary, traits are passed on, some variants reproduce more.
• Phylogenetic Trees:
  • Shared characters build family trees.
  • Three domains of life: Bacteria, Archaea, Eukarya.
• Endosymbiosis: Mitochondria (from proteobacteria) and chloroplasts (from cyanobacteria) were engulfed by eukaryotes.
• LUCA: Last Universal Common Ancestor, lived 4-4.3 billion years ago.

Three Domains of Life: Comparison

• Bacteria: Absent nuclear envelope and membrane-enclosed organelles, present Peptidoglycan in cell wall, present circular chromosome.
• Archaea: Absent nuclear envelope and membrane-enclosed organelles, Absent Peptidoglycan in cell wall, present circular chromosome.
• Eukarya: Present nuclear envelope and membrane-enclosed organelles, Absent Peptidoglycan in cell wall, Absent circular chromosome.

Key Equations and Units

• $1 \mu m = 10^{-3} mm$
• $1 mm = 1000 \mu m$
• $1 \mu m = 1000 nm$