BIOL107 Lecture 7: biol107 lecture 7 notes - january 29, 2019

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL107
• Professor: Martin Srayko

Document Summary

Adjacent animal cells can be connected by 3 types of junctions: tight junctions, desmosomes, gab junctions (communication junctions) Connexon - 6 protein subunits (each subunit is called a connexin) 2 connexons form a gap junction that spans the membranes of both cells. To compare, single-called life appeared on earth roughly 4 billion years ago. Eukaryotes didn"t really appear until approximately 2 billions years ago. This transition occurred via membrane folding and the acquisition of mitochondria/ chloroplasts. Origin of eukaryotes and the endosymbiont hypothesis: Most recent common eukaryotic ancestor probably arose about 2. 1 billion years ago. They may have rst evolved a way to fold their membrane. Metabolic requirements set upper limits on cell size. Sa to v ratio of cells is critical. Developed a way to create simple folds in the membrane, allowing the cell to get a little bit bigger.