Title 21. THE DYNAMIC CELL – STRUCTURES AND FUNCTIONS OF CELLULAR COMPONENTS.pdf ✅

PHARMD GURU Page 1 1) INTRODUCTION TO CELLULAR STRUCTURE AND FUNCTION: Cells are the basic units of life, responsible for carrying out essential biological processes such as growth, metabolism, and reproduction. They contain specialized structures, each with unique roles that contribute to cellular function and overall homeostasis. Cells are broadly classified into prokaryotic and eukaryotic cells, each with distinct structural and functional characteristics. A. PROKARYOTIC CELLS: Prokaryotic cells (e.g., bacteria, archaea) have a simple structure and lack membrane-bound organelles. Their genetic material is located in a nucleoid region, instead of a nucleus. KEY FEATURES OF PROKARYOTIC CELLS:  Plasma Membrane – Controls the movement of substances in and out of the cell.  Cytoplasm – The site of metabolic reactions.  Nucleoid – A region containing circular DNA (genetic material).  Ribosomes (70S) – Involved in protein synthesis.  Cell Wall – Provides structural support and protection (made of peptidoglycan in bacteria). B. EUKARYOTIC CELLS: Eukaryotic cells are larger and more complex than prokaryotic cells. They contain membrane-bound organelles, which compartmentalize cellular functions. KEY ORGANELLES IN EUKARYOTIC CELLS:  Nucleus – Stores DNA and controls cell functions.  Mitochondria – Generates ATP (energy) through oxidative phosphorylation.  Endoplasmic Reticulum (ER): THE DYNAMIC CELL – STRUCTURES AND FUNCTIONS OF CELLULAR COMPONENTS