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Tour of the Cell. What the cell??!. Basic unit of life 3.8 BYA Coacervates prokaryotes eukaryotes Von Leuwenhoek, Hooke, Schleiden, Virchowr Microscopes & resolution. Prokaryotic and Eukaryotic cells compared. Figure 4.4x5. PROKARYOTIC CELL. EUKARYOTIC CELL. Cell diversity.
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What the cell??! • Basic unit of life • 3.8 BYA • Coacervates prokaryotes eukaryotes • Von Leuwenhoek, Hooke, Schleiden, Virchowr • Microscopes & resolution
Prokaryotic and Eukaryotic cells compared Figure 4.4x5
PROKARYOTIC CELL EUKARYOTIC CELL
Cell diversity • many sizes • many shapes to suit their function • Stem cells are “pluripotent” – can differentiate to become anything • embryonic vs. adult
Cell Theory • All living things are made of cells • Cells are basic unit of life • All cells come from pre-existing cells
All cells… • Plasma or Cell membrane • Boundary for cell, cellular communication, cell attachment & support; cell metabolism • Cytoplasm • Site of most cellular metabolism • Within membrane; within organelles • DNA • Ribosomes to follow the directions
Nucleus • Genetic control center • Chromatin held on chromosomes • Nucleolus • Makes ribosomes
Cell membrane • Boundary • “Interface” between the inside world and the outside world of the cell • Semi-permeable fluid mosaic model • Acts as doors and windows to the cell
Cell membrane proteins function • Markers - ID tags for recognition • Transport channels for big molecules • Cell surface receptors – “antennae” of the cell • Enzymes – catalysts • Cell adhesion – cell to cell to form tissues • Scaffolding support – cytoskeleton attachment
cell communication & junctions • Cell wall & cell membrane • Plasmodesmata & Gap junctions – channels b/t cells • Extracellular matrix – glycoprotein “glue” • cell adhesion to form tissues • Tight Junctions • Anchoring junctions
Organelles (found only in Eukaryotes) • Organelles “organize” the cell • “little organs” • Allow for specialization • more efficient work • Membrane bound
Endomembrane System • System of cellular connection & communication • Formed from eukaryotic “infolding” of cell membrane • Help to further compartmentalize the cellular activities • Endoplasmic reticulum • Golgi apparatus • Vacuoles
Animal cells No cell wall Few vacuoles Nucleus centered No plastids Plant cells Cell wall Large central vacuole Nucleus pushed to side Plastids Spherosomes instead of lysosomes Compare Animal & Plant cell
Chloroplasts in plant cells Figure 4.5Bx2