11th Biology Chapter 8

– Important Topics:

1. What is a Cell?

– The cell is the fundamental structural and functional unit of all living organisms. It was first described by Anton Von Leeuwenhoek【4:0†source】.

2. Cell Theory

– Formulated by Schleiden, Schwann, and modified by Virchow; states that all living organisms are composed of cells and arise from pre-existing cells【4:0†source】.

3. An Overview of Cells

– Eukaryotic cells have a membrane-bound nucleus containing genetic material, while prokaryotic cells lack a membrane-bound nucleus. Both types contain cytoplasm as the main site of cellular activities【4:0†source】.

4. Prokaryotic Cells

– Simple cells lacking membrane-bound organelles like eukaryotic cells. Function with a semi-fluid matrix called cytoplasm【4:0†source】.

5. Eukaryotic Cells

– Cells with membrane-bound organelles like ER, golgi complex, lysosomes, mitochondria, and vacuoles. Have a distinct nucleus containing chromosomes and genetic material【4:0†source】.

6. Cell Membrane

– Composed of lipids, proteins, and cholesterol. Membrane proteins can be integral or peripheral. The fluid mosaic model explains the structure and functions of the membrane【4:1†source】.

7. Cell Wall

– Rigid structure outside the plasma membrane in plants and fungi. Provides shape, protection, and cell-to-cell interaction. Contains cellulose, hemicellulose, pectins, proteins, and middle lamella【4:2†source】.

8. Endomembrane System

– Includes ER, golgi complex, lysosomes, and vacuoles. Functions are coordinated within this system. Mitochondria, chloroplasts, and peroxisomes are not part of this system【4:3†source】.

– Summary: The chapter covers the fundamental concepts of cells as the basic units of life, the cell theory, differences between prokaryotic and eukaryotic cells, the structure and functions of cell components like the cell membrane and wall, and the coordination of functions within the endomembrane system.