Saturday, August 10, 2019

Describe how membrane structure is related to the transport of Essay

Describe how membrane structure is related to the transport of materials across a membrane and the role of membrandes in the synthesis of ATP in either respirat - Essay Example The alignment of these phospholipids along the cell membrane is tail to tail, so that these non polar areas form water repellant, hydrophobic regions on the inner and outer surfaces of the membrane, while the polar heads are hydrophilic and allow solvents to pass easily through. Lipids and proteins are not however likely to seep through the bilayer unless they first give up the favorable interactions with hydrogen molecules present in water before they can cross the membrane. The greater the degree to which a protein or lipid molecule is hydrophilic, the larger it is and therefore less likely to cross the cell membrane through simple diffusion. (Gray et al, 2002) The interaction between non polar lipid tails that limits membrane fluidity is due to the action of the Van der Waals forces, which are increased by increasing length of the lipid tails (Gray et al, 2002). It is the hydrophobic effect that results in the rapid self assembly of the lipid bilayers when exposed to water since protein folding takes place through the clustering of the hydrophibic residues in the core of the protein in order to prevent contact with water. However, this structure of the cell membrane is not rigid, because the forces holding the bilayer together are weak, non-covalent interactions which allow for fluidity of the membrane. The outer surface of the cell membrane is rich in glycolipids, while the hydrophobic tails are embedded within the cell. The heads which are exposed outside the cell function in association with the carbohydrates attached to the integral proteins in allowing the cell to determine which materials belong to the organism and which materials are foreign, against which an immune defense must be sparked. Water, carbon dioxide and oxygen are transported across the cell membrane through a simple process known as diffusion or Osmosis, where the

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