BIOL 1108 Lecture Notes - Lecture 5: Symbiogenesis, Endomembrane System, Cell Cycle
24 Oct 2018
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Document Summary
Eukaryotic cells are defined by the presence of a nucleus, but features like a dynamic cytoskeleton and membrane system explain their success in diversifying. The endosymbiotic hypothesis proposes that the chloroplasts and mitochondria of eukaryotic cells were originally free-living bacteria. Eukaryotes were formally divided into four kingdoms, but are now divided into at least seven superkingdoms. The fossil record extends our understanding of eukaryotic diversity by providing perspectives on the timing and environmental context of eukaryotic evolution. Cytoskeleton is a scaffolding of dynamic proteins. Endomembrane system of organelles is dynamic and interconnected. Active transport of particles of life is rapid. Vesicles instrumental in the movement of material throughout the cell and cytoplasm better than diffusion (speed) which means the eukaryotic cell can now be much bigger than most bacterial cells. Phagocytosis = engulf, package, transport, and digest food particles. Cell cycle differs when the organism reproduces sexually or asexually.
