Introduction to the Study of Life: Cells and Molecules

Introduction to the Study of Life

Overview of the Course

This section introduces the foundational concepts and questions in General Biology, focusing on the study of life at the molecular and cellular levels. Students will explore what defines life, major biological questions, and the scientific approach to understanding living systems.

• Course Introduction: Overview of instructor background and course logistics.

• Key Questions: What is life? How did it originate? What are the major questions in biology?

• Scientific Thinking: Emphasis on learning how to think and act like a scientist.

Defining Life

What is Life?

Biologists seek to define life by identifying characteristics shared by all living things. This is a central question in biology, with implications for understanding the origin and diversity of life.

• Seven Pillars of Life (Daniel Koshland, 2002): A framework for defining life, including properties such as compartmentalization, program (genetic information), improvisation (evolution), regeneration, adaptability, and energy utilization.

• Examples of Living Things: Organisms such as plants, animals, and microorganisms all exhibit these characteristics.

• Borderline Cases: Entities like viruses and prions challenge the definition of life, as they possess some but not all characteristics of living things.

Quiz: Are These Things Alive?

Students are encouraged to consider whether various entities (e.g., kelp, elephants, trees, otters) are alive, based on the characteristics of life.

• Key Criteria: Organization, metabolism, growth, adaptation, response to stimuli, reproduction, and homeostasis.

• Application: Use these criteria to evaluate ambiguous cases such as viruses, mitochondria, and prions.

Major Questions in Biology

Big Questions Addressed by Biologists

Biology seeks to answer fundamental questions about life and living systems. These questions drive research and discovery in the field.

• Origin of Life: How did life arise on Earth? What was the first life form?

• Evolution of Viruses: How did viruses originate?

• Aging and Lifespan: Why do organisms age, and how can lifespan and health be improved?

• Biodiversity: How many species exist on Earth?

• Protein Folding: How do proteins fold into functional shapes?

• Extraterrestrial Life: Is there life elsewhere in the universe?

The Scientific Method

How Scientists Investigate the Natural World

The scientific method is a systematic approach used by scientists to explore observations, answer questions, and test hypotheses.

1. Observation: Noticing and describing phenomena in the natural world.

2. Question: Formulating a question based on observations.

3. Hypothesis: Proposing a testable explanation for the observation.

4. Prediction: Making predictions that can be tested by experiments.

5. Experiment: Conducting experiments to test the predictions.

6. Analysis: Analyzing data to support or refute the hypothesis.

7. Revision: Revising the hypothesis or forming new ones based on results.

Example: If a flashlight does not work, possible hypotheses include dead batteries or a burnt-out bulb. Each hypothesis leads to a specific prediction and test.

Communication in Science

How Scientists Share Knowledge

Scientific progress depends on effective communication among researchers. Scientists share their findings through various channels:

• Presentations and Seminars: Sharing research with peers in formal settings.

• Scientific Conferences: Gathering to discuss new discoveries and ideas.

• Journal Articles: Publishing detailed reports of research for peer review and dissemination.

Course Structure and Expectations

How You Will Be Evaluated

The course includes a combination of lectures, quizzes, exams, and laboratory work. Students are expected to engage with the material and participate in assessments.

• Lecture (70%): Includes two quizzes (15% each), one final exam (30%), and online pre-quiz (7%).

• In-Class Participation: Poll questions (7%).

• Laboratory (30%): Hands-on experiments and assignments.

• Opportunities for Grade Improvement: Correction of test questions for partial credit recovery.

Course Themes for the Semester

Major Topics to Be Covered

The course will progress from the molecular to the organismal level, covering key topics in biology:

• Water and Carbon: Fundamental molecules of life (Chapters 2-4).

• Enzymes and Metabolism: Biochemical processes (Chapters 5-6).

• Cells and Organelles: Structure and function of cells (Chapters 7-12).

• Organisms: Diversity and function of living organisms (Chapters 13-17).

Additional info: Students are encouraged to read assigned textbook chapters and complete online quizzes to reinforce learning.