Ch 1 lecture

Course Information

Overview of Cell Biology 213

This course introduces students to the fundamental concepts of cell biology, focusing on the structure, function, and processes of cells. Students will explore the major components of cells, including their metabolism, signaling pathways, and the cell cycle.

• Instructor: Dr. Jasmine R. Robinson

• Educational Background:

  • Bachelor's: Physiology and Neurobiology

  • Master's: Applied Clinical Nutrition

  • Doctorate: Doctorate of Chiropractic

• Office Hours: By appointment only (see syllabus for scheduling)

• Email: [e-mail]

• Experience: Over 14 years of clinical practice; currently in active practice

Course Policies

• Attendance: Students are required to attend class and be on time. Excused absences require proper documentation.

• Emergencies: Must be emailed to Dr. Weatherspoon and Hermoso, with the instructor cc'd.

• Administrative Questions: Directed to Dr. Weatherspoon and Hermoso; cell biology questions to Dr. Robinson.

• Course Focus: In-depth study of cell structure, function, metabolism, signaling, and the cell cycle.

• Required Reading: Syllabus and textbook are essential for success in the course.

• Course Motto: "If you are not living, you are not learning."

What Is Biology?

Definition and Scope

Biology is the scientific study of living things, known as organisms. The field encompasses a vast range of life forms, from microscopic bacteria to large plants and animals.

• Organisms: Any living entity, including bacteria (Bacillus, Escherichia coli), plants, and animals.

• Common Ancestry: All life shares a common ancestor, highlighting the unity and diversity of life.

Examples:

• Bacillus (bacterium, ~0.5 μm)

• Escherichia coli (bacterium, ~1 μm)

• Chromospheres (eukaryotic cell, ~1 μm)

Life's Timeline

Major Events in the History of Life on Earth

The history of life on Earth spans billions of years, with key evolutionary milestones marking the development of complexity and diversity among organisms. The following timeline uses a calendar analogy to illustrate the relative timing of these events.

Origin of Life (Day 3)

• Life is believed to have originated from non-living matter, possibly near hydrothermal vents in the ocean, about 4 billion years ago.

Oldest Fossils (Day 13)

• The oldest known fossils are about 3.5 billion years old, representing some of the earliest prokaryotic life forms.

Origin of Photosynthesis (Day 13)

• Photosynthesis evolved in certain prokaryotes, allowing organisms to convert sunlight into chemical energy and release oxygen as a byproduct.

• This process led to the accumulation of oxygen in Earth's atmosphere, enabling the evolution of aerobic (oxygen-using) organisms.

Origin of Eukaryotic Cells (Day 20)

• Eukaryotic cells contain membrane-bound organelles, including a nucleus. They are thought to have evolved through endosymbiosis, where one cell engulfed another, leading to the development of mitochondria and chloroplasts.

• This event marked a significant increase in cellular complexity.

Multicellular Organisms (Day 24)

• The evolution of multicellularity allowed for greater specialization and complexity, leading to the development of diverse plant and animal lineages.

Abundant Fossils of Aquatic Life, First Land Plants and Animals (Day 27)

• Life in the oceans became diverse and abundant, with the first evidence of land plants and animals appearing.

• Major groups such as arthropods and amphibians colonized land.

Coal Forming Forests, Insects Abundant, First Mammals, Dinosaurs Dominate (Days 28-29)

• Forests capable of forming coal appeared, and insects became highly diverse.

• The Mesozoic Era, or "Age of Reptiles," was marked by the dominance of dinosaurs.

First Birds, First Flowering Plants, Rise of Mammals (Days 29-30)

• Birds and flowering plants emerged, representing significant evolutionary developments.

• Mammals, initially small and nocturnal, diversified after the extinction of dinosaurs.

First Hominids (Near the End of Day 30)

• The ancestors of humans appeared very late in the timeline, emphasizing how recent human evolution is in Earth's history.

Summary Table: Major Events in Life's Timeline

Event	Approximate Time (Calendar Analogy)	Significance
Origin of Life	Day 3	First living cells appear
Oldest Fossils	Day 13	Evidence of early prokaryotes
Origin of Photosynthesis	Day 13	Oxygen production begins
Origin of Eukaryotic Cells	Day 20	Complex cells with organelles
Multicellular Organisms	Day 24	Specialization and complexity increase
First Land Plants and Animals	Day 27	Colonization of land
Coal Forests, Insects, Mammals, Dinosaurs	Days 28-29	Major diversification and dominance of dinosaurs
First Birds, Flowering Plants, Mammals Rise	Days 29-30	Significant evolutionary innovations
First Hominids	End of Day 30	Human ancestors appear

Additional info: The calendar analogy helps students appreciate the vast timescales involved in the evolution of life and the relatively recent appearance of humans.