BIOL101 Lecture Notes - Lecture 10: Trac, Lysosome, Mitochondrion
14 Oct 2017
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Document Summary
Hypothesis is that through evolu?on many membranes derived from the same one. Insulin is a peptide hormone, produced by pancreas beta cells. Insulin regulates glucose levels in the body, by signaling cells to absorb glucose from the blood: diabetes mellitus is a result of defective insulin production or function. Insulin synthesis and secretion: insulin is translated as preproinsulin as a single oligopeptide, proinsulin is formed by cleaving the signal peptide, insulin is formed by cleaving off the c peptide from proinsulin. Ribosomes: free in cytoplasm or associated with part of endomembrane system. Free to bound ribosomes: signal peptide (sequence of approx. 20 amino acids) is detected by signal-recognition particle (srp) on er and directs entire ribosomal unit to the er membrane: ribosomal unit binds to er membrane and translation continues. Reticulum (rer: signaling peptide removed, protein folded, disulfide bridge formed. Tags proteins for sorting to their final destinations.
