Learning Outcomes:
i. Students will illustrate the structure and functions of the organelles within an animal cell.
ii. They will describe the structure, parts, and function of the nucleus.
iii. Students will explain the structure, parts, models, and functions of the cell membrane.
Summary of Lesson:
An animal cell is a microcosm of complex and dynamic structures, each with specialized roles. Two key components - the nucleus and the cell membrane - function as the administrative center and the security system of the cell, respectively. This lesson will explore these organelles in detail, revealing how they contribute to the cell's survival and function.
The Nucleus: Command Center of the Cell
Structure and Parts:
i. Nuclear Envelope: A double-layered barrier that houses the DNA and nucleolus.
ii. Nucleoplasm: Gel-like substance within the nuclear envelope.
iii. Chromosomes: Structures consisting of DNA and protein; the cell's hereditary units.
iv. Nucleolus: Site of ribosome assembly.
Functions:
i. Houses genetic material that dictates cellular function and heredity.
ii. Coordinates cell activities such as growth, intermediary metabolism, protein synthesis, and reproduction (cell division).
The Cell Membrane: Guardian of the Cell
Structure and Parts:
i. Phospholipid Bilayer: Provides a flexible matrix and barrier.
ii. Proteins: Serve various roles including transport, cell communication, and structural support.
iii. Cholesterol: Modulates fluidity and mechanical strength.
iv. Carbohydrates: Involved in cell recognition and interaction.
Models: Fluid Mosaic Model: Depicts the cell membrane as a fluid combination of phospholipids, cholesterol, proteins, and carbohydrates.
Functions:
i. Maintains the integrity of the cell by regulating the passage of materials.
ii. Facilitates communication with other cells and the extracellular environment.
iii. Provides a selectively permeable barrier, allowing for necessary substances to enter and waste to exit.
List of Important Questions for Self-Study:
i. What are the main structural components of the nucleus, and what are their functions?
ii. How does the cell membrane maintain the internal environment of the cell?
iii. What is the fluid mosaic model, and why is it an important concept in cell biology?
iv. How do ribosomes, produced in the nucleolus, reach their sites of function in the cytoplasm?
v. What role do proteins and carbohydrates play in the function of the cell membrane?
vi. In what way does the nuclear envelope control the flow of genetic information?
vii. Why is cholesterol important to the cell membrane?
viii. How does the structure of the nuclear envelope facilitate its function?
ix. What might happen to a cell if its membrane loses its integrity?
x. How can mutations in the DNA within the nucleus affect overall cell function?
Important Terminologies Used in Lesson:
i. Organelle: Specialized subunit within a cell that has a specific function.
ii. Nucleus: An organelle that contains the cell's DNA and is the control center of the cell.
iii. Cell Membrane: The lipid bilayer that encloses the cytoplasm and controls the movement of substances in and out of the cell.
iv. Phospholipid Bilayer: The fundamental structure of the cell membrane, composed of two layers of lipid molecules.
v. Chromosomes: Thread-like structures located within the nucleus, made of DNA wrapped around proteins.
vi. Fluid Mosaic Model: A model that conceptualizes the cell membrane as a dynamic and fluid structure with a mosaic of various proteins.
