INTO THE REALM OF CELLS Prokaryotes Eukaryotes Viruses

What do you already know about cells? Cells are enclosed in semipermeable membranes Cell Theory All living organisms are composed of one or more cells The cell is the most basic unit of structure, function, and organization in all organisms Cells come from pre-existing, living cells

What are the two types of cells? Prokaryotes characterized by the absence of a distinct, membrane-bound nucleus or membrane- bound organelles, and by DNA that is not organized into chromosomes. Examples: bacteria

What are the two types of cells? Eukaryotes A single-celled or multi-cellular organism whose cells contain a distinct membrane- bound nucleus. Examples: Plant Cell Animal Cell

Prokaryote vs. Eukaryote How are Prokaryotes and Eukaryotes similar? How are Prokaryotes and Eukaryotes different? Nucleus Organelles Cytoskeleton Complex DNA Large Capsule Circular DNA Small Cell Membrane Ribosomes Cytoplasm Flagella

Eukaryote – Animal Cell cells with a membrane-bound nucleus; have many different forms Cheek Cell Heart Cell

Eukaryote – Plant Cell a cell that is a structural and functional unit of a plant Cross-section of plant leaf

Animal Cell vs. Plant Cell Cell Membrane Endoplasmic Reticulum Ribosomes Mitochondria Golgi Apparatus Nucleus Vacuoles Nuclear Membrane Cell Wall Chloroplast Centriole Lysosomes

Viruses Any of various simple submicroscopic parasites of plants, animals, and bacteria that often cause disease and that consist essentially of a core of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms. Example: Common Cold, Ebola, AIDs

General Structure of a Virus

Let’s Compare Them! Prokaryote Eukaryote Viruses Cell Membrane Ribosomes Cytoplasm Flagella Nucleus Organelles Cytoskeleton Complex DNA Large Capsule Circular DNA Small DNA or RNA No Cell Viruses

Why does this matter? By knowing how a virus infects different types of cells, we can create vaccines Cells are the building blocks of life Without this knowledge, serious diseases like cancer cannot be stopped By understanding plant cells, we can see how they benefit humans Food, medicines, heat (burning of wood), buildings

Discussion Question What would the world be like without viruses? Would it be a better place? Why or Why not?