7-1 Cell Theory Prokaryotes vs. Eukaryotes Cells
How were cells discovered? The first cell was discovered when Robert Hooke looked at cork under a microscope! • He saw thousands of tiny empty chambers
History of the Cell 1839: Schwann concludes that animals are made of cells 1838: Schleiden concludes that plants are made of cells 1855: Virchow proposes that all cells come from other cells completing the cell theory 1665: Hooke discovers the cell 1674: Van Leeuwenhoek observed tiny living organisms in pond water
Cell Theory • All living things are made of cells. • A cell is the smallest unit of life. • All cells come from preexisting cells.
Cell membrane Cytoplasm Cell membrane Cytoplasm Prokaryote vs. Eukaryote Prokaryotic Cell (bacteria) Eukaryotic Cell (plants and animals) Nucleus Organelles
Prokaryotes • Unicellular (Single celled) • No nucleus- DNA is located in the cytoplasm in a simple circle www.blobs.org/science/cells/prokaryote.gif
Eukaryotes • Contain organelles • Often multi-cellular • DNA is found chromosomes located inside the nucleus • These are the cells that YOU have!
Organelle • What is an organelle? • A membrane bound structure that separates cell functions • Found in Eukaryotic cells • “little organ”
2 Basic Cell Types Prokaryotes Eukaryotes
Prokaryotes vs. Eukaryotes Eukaryotes Prokaryotes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell membrane Contain DNA Ribosomes