Knowt
Lecture 1 introduction to Bio
Lecture Overview
Lecture 1 - What is life?
Instructor Background
Dr. Chris Gregg
Concordia University
Education:
2000-2004: B.Sc.
2004-2009: PhD in lifespan of Eukaryotic cells on calorie-restricted diet.
Postdoctoral Research:
Genetic Engineering of Yeast for drug production.
Study Advice
Stay on Top of Your Work
Attend all lectures and take notes.
Complete readings/videos before class.
Bring and update notes in class.
Participate actively.
Study with a partner.
Seek help during office hours if needed.
Student Responsibilities
Watch videos/read before lectures.
Complete online quizzes.
Arrive prepared for open-book activities.
Chapter Insights
Chapter 1 - Exploring Life
Important Biological Concepts
The Process of Science
Definition of Biology
Etymology:
bios = life, logos = reasoned account
Biology = study of life
Biophile = affinity for living things
Scope of Biology
Topics Covered:
Living organisms' structure, function, growth, origin, evolution, and distribution.
Fields include:
Human Biology
Molecular Biology
Biochemistry
Neurobiology
Genetics
Ecology
Role of Biologists
Key Activities:
Pose questions about life.
Seek science-based answers.
Discover mechanisms governing organism functionality.
Current Era of Biology
Significance:
Research breakthroughs transforming medicine, agriculture, and industry.
Example: Biosynthetic corneas (University of Ottawa, Sweden) for damaged eye tissue.
Example: Beating heart in lab (Dr. Doris Taylor, University of Minnesota).
Fundamental Characteristics of Life
All organisms share five main characteristics:
Cells - made up of membrane-bound cells.
Energy - acquire and use energy.
Information - process hereditary information in genes.
Replication - capable of reproduction.
Evolution - populations of organisms evolve.
Levels of Biological Organization
Hierarchy:
Organism
Organ System
Organ
Tissue
Cell
Molecule
Atom
Cell Structure and Function
Phospholipids
Properties:
Amphipathic: hydrophilic (water-attracting) head and hydrophobic (water-repelling) tail.
Do not dissolve in water; instead form structures:
Micelles: heads face water, tails face each other.
Phospholipid bilayers: double layer arrangement.
Cell membranes are made from phospholipids.
Liposomes
Formed from phospholipid bilayers, resembling balloons.
Amphipathic Proteins
Structure:
Can integrate into lipid bilayers.
Made of both polar (hydrophilic) and non-polar (hydrophobic) amino acids.
Cell Definition
Cell:
Smallest unit of life, self-replicating, membrane-bound structure that maintains homeostasis.
Types of Cells
Eukaryotic vs. Prokaryotic Cells
Eukaryotic Cells:
Have a nucleus, membrane-bound organelles (includes animals, plants, fungi).
Prokaryotic Cells:
Lack a nucleus and membrane-bound organelles (e.g., bacteria like E. coli, Salmonella).
Energy Utilization
Process:
Organisms acquire energy from the environment, mainly through consumption.
Energy is used for bodily functions and maintaining homeostasis.
Homeostasis Examples:
Constant temperature (e.g., 37°C in humans).
Blood glucose levels maintained at 79.2 to 110 mg/dL.
Disruption indicates illness.
Hereditary Information Processing
Key Points:
DNA: nucleic acid forming a double-stranded polymer.
Chromosome: structure of DNA and proteins; eukaryotes have linear chromosomes (e.g., humans have 46).
Gene: segment of DNA coding for specific proteins; all traits ultimately result from proteins.
Evolutionary Context
Relationship of Life on Earth:
All life is interrelated through evolution.
Timeline Overview (Approximate):
4.5 billion years: Earth;
3.8 billion years: simple cells (prokaryotes);
3 billion years: photosynthesis;
2 billion years: complex cells (eukaryotes);
1 billion years: multicellular life;
600 million years ago: simple animals;
65 million years ago: non-avian dinosaurs extinction.
Perception of Time
Analogy of Time:
5 billion years equals a very short duration in a human lifespan (0.01 seconds on a scale).
