BIOL 2030 Lecture Notes - Lecture 15: Keystone Species, Smooth Muscle Tissue, Cell Membrane
10 Nov 2018
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Keystone species: keystone species influence community structure and dynamics out of proportion to their abundances, fragmented are: more extinction; need to maintain distribution and abundance, muscular system, smooth muscle: smooth muscle provides contractile force for internal organs. Smooth muscle cells are electrically connected by gap junctions, so action potentials can spread rapidly throughout smooth muscle tissue. The ca2+ ions bind to troponin and change its conformation, pulling the tropomyosin strands away from the myosin binding sites on the actin filament. To prevent the organism itself from being digested, these enzymes are released as inactive zymogens, which become activated when secreted into the gut: fat digestion: micelles on biled fat are attached by lipase. Fats are broken down by lipases and absorbed mostly as monoglycerides and fatty acids. These products pass through the membranes of mucosal cells and are then resynthesized into triglycerides within the cells.
