BI110 Lecture Notes - Lecture 17: Cell Membrane, Peripheral Membrane Protein, Integral Membrane Protein
Document Summary
Cells and organelles need barrier to separate internal and external contents. Permeable to water (water must get into membrane) I(cid:374)solu(cid:271)le i(cid:374) (cid:449)ater (cid:894)(cid:272)a(cid:374)(cid:374)ot dissol(cid:448)e i(cid:374) (cid:449)ater (cid:271)e(cid:272)ause it (cid:449)ould(cid:374)"t (cid:271)e a(cid:271)le to prote(cid:272)t the (cid:272)ell(cid:895) *important in communicating and responding to the environment. Boundary nad permeability barrier: organization and location of function, transport processes (controlled import and export of things through the cell) Signal detection (stimuli that the cell can detect: cell-to-cell interactions. Cholesterol (animals) ** essential not always bad. Integral proteins (usually transmembrane embedded in the membrane) Peripheral membrane proteins (just interacts with surface; can be easily removed) Carbohydrates (located on the extracellular side of membrane) Cytoskeleton (linking 2 different compartments of the membrane) *me(cid:373)(cid:271)ra(cid:374)es are (cid:374)ot ho(cid:373)oge(cid:374)ous there are differe(cid:374)t arra(cid:374)ge(cid:373)e(cid:374)ts of these (cid:272)o(cid:373)po(cid:374)e(cid:374)ts. Structural proteins (that give the cell its shape) Integral membrane proteins are amphipathic, containing both hydrophobic and hydrophilic amino acids *** (example rodopsin)
