Prokaryotes and Eukaryotes PDF

CELL BIOLOGY Dr. Madani S. 2024/2025 The Cell The cell is the fundamental, structural, functional, and reproductive unit of life that can function autonomously (respiration, metabolism, cell division, and movement). All cells share some basic features: Cell membrane Cytoplasm Genetic ma...

CELL BIOLOGY Dr. Madani S. 2024/2025 The Cell The cell is the fundamental, structural, functional, and reproductive unit of life that can function autonomously (respiration, metabolism, cell division, and movement). All cells share some basic features: Cell membrane Cytoplasm Genetic material The cell is an enclosed compartement CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025  Are Viruses considered as cells? CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Viruses Viruses are not considered cells. They are akaryotes (acellular), which means they lack the basic structures and functions of a cell. Viruses do not have a nucleus, cytoplasm, or membrane-bound organelles. They are also unable to reproduce on their own or have their own metabolism. Instead, they rely on host cells to replicate their genetic material and produce new virions. CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Prokayotic Cells (Prokaryotes) CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2023-2024  Prokayotes 1- Definition: Prokaryote ( Greek “before nucleus”) known to be the earliest on earth. They include two domains : Archaea: Primitive Prokaryotes, found in extreme environment Bacteria also called (eubacteria): Modern Prokaryotes, found everywhere and can be helpful or harmful ❑ Archaea and Bacteria are different at the molecular level CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Prokayotes 1- Definition: Prokaryote ( Greek “before nucleus”) Single-celled (Unicellular) microorganisms Lacks a distinct nucleus ( genetic material is free within the cell) Lacks organelles due to the absence of internal membranes Ribosomes are present Very small size : 10 µM in length and Increased complexity than Prokaryotes CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukaryotes They have a nuclear membrane and nucleolus Mitochondria, Golgi apparatus, endoplasmic reticulum, chloroplast, and lysosomes are present. The genetic material is present on more than one chromosome. They have the histone proteins The cell wall is made up of cellulose. cell respiration is done via the mitochondria. Cell division involves mitosis and meiosis (gametes). The gene exchange involves sexual reproduction CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukaryotes Animal Cell Have circular or irregular shape Contain the same organelles as the plant cell except for : Cell Wall and Chloroplast Can contain many smaler vacuoles than a plant cell Can have cilia and flagella Size: 10-30 µM CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukayotes Micrograph of epithelial cells Observed with the light microscope Transmission Electron Micrograph Of an epithilal cell CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukaryotes Plant Cell Have a regular shape typically larger than animal cells Contain the same organelles as the animal cell + Cell Wall and Chloroplast Contain a large vacuole Lack of flagella and cilia Size: 10-100 µM CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukaryotes Plant Cell Micrograph of plant cells Observed with the light microscope Transmission Electron Micrograph Of a plant cell CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukaryotes Plant cell Animal Cell CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025  Are red blood cells considered as Eukaryotes? CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025 Eukayotes Erythrocytes Erythrocytes also called Red blood cells are unique eukaryotes in that they lose their nucleus when they mature. This allows them to carry more oxygen, as there is more room for hemoglobin, the protein that binds to oxygen. Red blood cells also have a flattened, biconcave shape, which increases their surface area and allows them to exchange oxygen and carbon dioxide more efficiently. CELL BIOLOGY/ 1st Academic year / Dr. MADANI S. /2024-2025