1.1.5 The two most important energy conversion processes, photosynthesis(occurring in the inner membranes of chloroplasts) and oxidative phosphorylation(ocurring in the inner membranes of mitochondria) are carried out by membrane systems 1. 1.6 Certain biosynthesis(e.g, synthesis of lipids and some proteins, smooth ER )occur on biomembranes
1.1.5 The two most important energy conversion processes, photosynthesis (occurring in the inner membranes of chloroplasts) and oxidative phosphorylation (ocurring in the inner membranes of mitochondria) are carried out by membrane systems. 1.1.6 Certain biosynthesis (e.g., synthesis of lipids and some proteins, smooth ER?) occur on biomembranes
1.2 Many common features underlie the diversity of biological membranes. 1.2.1 All membranes share a“ three-layer” sheet-like appearance(of 6 to 10 nm thick under electron microscopic examination, with two electron-dense layers separated by a less dense central region. 1.2.2 All membranes are closed entities
1.2 Many common features underlie the diversity of biological membranes. 1.2.1 All membranes share a “three-layer”, sheet-like appearance (of 6 to 10 nm thick) under electron microscopic examination, with two electron-dense layers separated by a less dense central region. 1.2.2 All membranes are closed entities
1.2.3 Membranes consist mainly of lipids and proteins with mass ratio ranges between 1: 4 to 4: 1(membranes with different functions have different proteins, some lipids and proteins have covalently linked carbohydrates) 1.2.4 Membranes contain specific proteins (e.g, pumps, channels, receptors, energ. transducers, and enzymes) to mediate their distinctive functions
1.2.3 Membranes consist mainly of lipids and proteins with mass ratio ranges between 1:4 to 4:1 (membranes with different functions have different proteins, some lipids and proteins have covalently linked carbohydrates). 1.2.4 Membranes contain specific proteins (e.g., pumps, channels, receptors, energy transducers, and enzymes) to mediate their distinctive functions
1. 2.5All membrane lipids are amphipathic that form bilayer structures spontaneously in aqueous media. 1.2.6 Membranes are cooperative noncovalent assemblies 1.2.7 Membranes are always asymmetric with two different faces 1.2.8 Membranes are fluid two-dimensiona structures(the fluid mosaic model) with oriented proteins and lipids(which form bilayer structures) that can diffuse laterally but not vertically.(fig and video)
1.2.5 All membrane lipids are amphipathic that form bilayer structures spontaneously in aqueous media. 1.2.6 Membranes are cooperative noncovalent assemblies. 1.2.7 Membranes are always asymmetric with two different faces. 1.2.8 Membranes are fluid two-dimensional structures (the fluid mosaic model) with oriented proteins and lipids (which form bilayer structures) that can diffuse laterally but not vertically. (fig and video)
1.2.9 Most membranes are electrically polarized with inside negative(--70 mV)(the membrane potential plays a key role in transport, energy conversion, and excitability). 1.3 Proteins attach to membranes in different wavs 1.3.1 Some proteins, called integral proteins span the lipid bilayer (e.g glycophorin in erythrocyte, bacteriorhodopsin in halobacterium halobacterium)
1.2.9 Most membranes are electrically polarized with inside negative (~-70 mV) (the membrane potential plays a key role in transport, energy conversion, and excitability). 1.3 Proteins attach to membranes in different ways. 1.3.1 Some proteins, called integral proteins, span the lipid bilayer (e.g., glycophorin in erythrocyte, bacteriorhodopsin in halobacterium halobacterium)