Cell Theory and Functions

Cell Theory

• Cells are essential as they act like building blocks in the structure and function of life.
• Pioneering scientists contributed to the development of cell theory, highlighting the significance of cells in living organisms.

Learning Outcomes

• Understand and explain the postulates of the cell theory.
• Describe general cell features and their functions.
• Create a timeline detailing the discovery of the cell.
• Identify the key scientists behind cell theory and analyze its foundational principles.

Overview of Cells

• Cells are notably small; their size is closely linked to their functional efficiency.
• Small cell size aids in rapid transport of materials and efficient metabolic processes.

Functions of Cells

• Homeostasis: Cells regulate their internal environment to maintain a stable, constant state crucial for survival.
• Acquisition and Utilization of Energy: Cells obtain energy from food molecules, converting it into forms usable for various cellular activities.
• Responsiveness to Environment: Cells react to stimuli in their environment, allowing them to adapt and maintain internal balance.
• Protection and Support: Cells provide structural integrity and protection, essential for organism functionality.

Energy Functions

• Energy is stored in chemical bonds of food molecules and used by cells for diverse functions:
  • Heart cells pump blood, responding to energy needs.
  • Intestinal cells break down food.
  • Skeletal cells enable movement.
  • Nerve cells transmit information.

Responsiveness

• Cells must detect environmental changes to generate appropriate responses and preserve homeostasis.
• Example: Increased melanin production in the skin in response to UV radiation enhances protection against DNA damage.

Importance of Homeostasis

• Maintaining homeostasis is critical as most cells require specific conditions to function effectively.
• Mechanisms like perspiration and shivering are examples of how the body regulates temperature to support cellular functions.