Introduction To Biology

Learning Objectives

By the end of the course, students will be able to:

• Explain biology and articulate the seven properties of life, understanding their implications for living organisms.

• Differentiate effectively between prokaryotic and eukaryotic cells, including their structures and functions.

• Understand the critical functions and roles of nucleic acids and proteins in biological systems.

• Identify the three domains of life (Bacteria, Archaea, Eukarya) and describe their distinct characteristics.

• Define emergent properties with specific examples, illustrating how complexity arises from simpler components.

Definition of Biology

Biology: The scientific study of life, where "Bio" translates to life and "logy" refers to study. Biologists explore organisms of all sizes, from microscopic bacteria to large mammals.

• Biology is the scientific study of life

Seven Properties of Life

Characteristics that define living things:

• Order: all living things have structure and organization

• Regulation(homeostasis): all living things maintain stable internal conditions

• Evolutionary Adaptation: have to adapt to environment; all living things must change to live in their environments

• Reproduction: making offsprings (babies)

• Energy processing(metabolism): all living things use energy

• Response to the environment: all living things reactant to external stimuli

• Growth and development: process of change (time)

Cell Structure

Cells: the most basic unit of life

• Eukaryotic cells:

  • Have a nucleus and membrane-bound organelles.

  • Example components include membrane, cytoplasm, and nucleus.

• Prokaryotic cells:

  • Lack a nucleus; their DNA is scattered throughout the cell.

  • General structure includes a membrane and DNA.

Prokaryotic Organisms

Characteristics:

• Typically unicellular and microscopic in size.

• A classic example includes bacteria, which are found in diverse environments.

• Components include genetic material, macromolecules for metabolism, a membrane, and often a cell wall.

• No nucleus, no organelles, similar, simpler; bacteria and archaea

Eukaryotic Organisms

Characteristics:

• Larger and more complex cells featuring membrane-bound organelles.

• Can be unicellular or multicellular

• Contains distinct organelles such as the nucleus and mitochondria, each performing specialized functions.

• have nucleus(DNA) and other organelles larger, more complex and organized

Diversity of Cells

Overview:

• Cells exhibit an array of shapes and sizes, with their diversity being critical for the unique biological functions they perform.

Genetic Information

Nucleic Acids:

• Molecules such as DNA (deoxyribonucleic acid) carry genetic information crucial for inheritance, cellular function, and organism development.

Three Domains of Life

Domains:

1. Bacteria: Prokaryotic and unicellular, microscopic

2. Archaea: Prokaryotic and unicellular, microscopic, not disease causing

3. Eukarya (Eukaryotic): Both unicellular and multicellular; microscopic/macroscopic encompasses kingdoms like Animalia, Plantae, Fungi, and Protists

Domain Bacteria

Features:

• Prokaryotic and unicellular, microscopic

• Can perform beneficial roles such as symbiosis

Domain Archaea

Features:

• Prokaryotic and unicellular, known for their ability to thrive in extreme environments (e.g., hot springs, salt lakes).

• Often studied for their unique biochemical properties and potential applications in biotechnology.

Domain Eukarya

Features:

• Comprises a wide variety of organisms, both unicellular (e.g., protists) and multicellular (e.g., plants and animals).

• Kingdoms include Animalia (animals), Plantae (plants), Fungi (fungi), and Protists (unicellular organisms).

Biological Classification

Taxonomy: Branch of biology that classifies and names organisms.

• Helps biologists organize, identify, and understand the relationships between species (study the diversity of life)

Evolutionary Relationships

Overview:

• Evolution explains the unity and diversity of life which is also the foundation of biology.

Organizational Levels of Life

Organization:

• Atoms form molecules, which subsequently combine to create larger molecules that manage metabolic processes.

• Aggregates of molecules produce cells, which are considered the independent units of life, forming the basis for all living organisms.

Emergent Properties

Concept:

• New characteristics that result from the combination of smaller things together.

• For example, life itself is viewed as an emergent property arising from the complex interactions among various components of cells.

Vocabulary

Key terms for understanding biology:

• Cell - basic unit of life

• Taxa - groups

• Organelle - sub cellular structure that has 2 or more jobs to perform in a cell

• Domain - bacteria, archaea, eukarya

• Prokaryote - organism that has no nucleus, no organelles, simpler

• Kingdom - animalia, plantae, fungi, protista

• Eukaryote - organisms that has a nucleus and other large organelles, more complex

• Emergent property - foundation of biology; explains the diversity of life

• Unicellular - “uni” single “cellular” cell

• Multicellular - “multi” many

• Microscopic - small

• Macroscopic - big

• Taxonomy - branch of biology that classifies and names organisms