BIOLOGY 2B03 Lecture Notes - Lecture 8: Phagocytosis, Neutrophil, Platelet-Activating Factor
5 Mar 2016
School
Department
Course
Professor
Document Summary
Wilson took multicellular organisms from two different sponge species, and separate the individual cells, then mixed them together. He found that cells from the same species adhered back together. Ie. the cells from different species did not adhere. Separated individual cells from two different germ layers of a frog embryo, then mixed them together. Found that cells from the same tissue recognized and adhered to each other. In embryos, the cam cells found each other and binded. Cams, cell adhesion molecules: transmembrane proteins found in the cell membrane: tight junctions; b. adherens junctions; c. desmosomes; d. hemidesmosomes; e. gap junctions. Epithelial cells adhere to each other laterally to form epithelial sheets that covers the body cavity. Cells have differing apical (top) and basal (bottom) surfaces. Basal: anchored to extracellular structures, acting as support whilst forming another structure ie. basal lamina/basement membrane. Hemidesmosomes: adhesion complexes that connect cells to extracellular matrix.
