scholarly journals Structure and Function of the Plasma Membrane

1968 ◽  
Vol 52 (1) ◽  
pp. 257-278 ◽  
Author(s):  
Edward D. Korn

The paucimolecular unit membrane model of the structure of the plasma membrane is critically reviewed in relation to current knowledge of the chemical and enzymatic composition of isolated plasma membranes, the properties of phospholipids, the chemistry of fixation for electron microscopy, the conformation of membrane proteins, the nature of the lipid-protein bonds in membranes, and possible mechanisms of transmembrane transport and membrane biosynthesis. It is concluded that the classical models, although not disproven, are not well supported by, and are difficult to reconcile with, the data now available. On the other hand, although a model based on lipoprotein subunits is, from a biochemical perspective, an attractive alternative, it too is far from proven. Many of the questions may be resolved by studies of membrane function and membrane biosynthesis rather than by a direct attack on membrane structure.

1982 ◽  
Vol 60 (9) ◽  
pp. 1171-1176 ◽  
Author(s):  
Hung Lee ◽  
E. A. Hosein

The effect of chronic alcohol administration on the structure and function of the rat liver plasma membranes has been investigated. Chronic alcohol administration did not affect the yield of these membranes using conventional isolation procedures. The extent of plasma membrane enrichment or contamination with other interior membranes was identical in the control and alcoholic preparations. The binding of 125I-labelled glucagon to these experimental liver plasma membranes was significantly decreased. Scatchard analysis of the high affinity sites showed a significant reduction [Formula: see text] in receptor number rather than binding affinity, which was not altered. This anomaly persisted through 72-h withdrawal of alcohol. These data suggest that very stable changes were induced in these liver plasma membranes after prolonged alcohol ingestion.


1999 ◽  
Vol 79 (1) ◽  
pp. S23-S45 ◽  
Author(s):  
DAVID N. SHEPPARD ◽  
MICHAEL J. WELSH

Sheppard, David N., and Michael J. Welsh. Structure and Function of the CFTR Chloride Channel. Physiol. Rev. 79 , Suppl.: S23–S45, 1999. — The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique member of the ABC transporter family that forms a novel Cl− channel. It is located predominantly in the apical membrane of epithelia where it mediates transepithelial salt and liquid movement. Dysfunction of CFTR causes the genetic disease cystic fibrosis. The CFTR is composed of five domains: two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory (R) domain. Here we review the structure and function of this unique channel, with a focus on how the various domains contribute to channel function. The MSDs form the channel pore, phosphorylation of the R domain determines channel activity, and ATP hydrolysis by the NBDs controls channel gating. Current knowledge of CFTR structure and function may help us understand better its mechanism of action, its role in electrolyte transport, its dysfunction in cystic fibrosis, and its relationship to other ABC transporters.


2019 ◽  
Vol 20 (6) ◽  
pp. 1353 ◽  
Author(s):  
Quan Wang ◽  
Sha Yang ◽  
Shubo Wan ◽  
Xinguo Li

As a secondary messenger, calcium participates in various physiological and biochemical reactions in plants. Photosynthesis is the most extensive biosynthesis process on Earth. To date, researchers have found that some chloroplast proteins have Ca2+-binding sites, and the structure and function of some of these proteins have been discussed in detail. Although the roles of Ca2+ signal transduction related to photosynthesis have been discussed, the relationship between calcium and photosynthesis is seldom systematically summarized. In this review, we provide an overview of current knowledge of calcium’s role in photosynthesis.


‘Cellular structure and function’ covers the roles, structures, and functions of the main four types of macromolecules of the human body, namely proteins, lipids, carbohydrates, and nucleic acids. For these macromolecules, the roles and types of each class are discussed (for proteins this includes their roles as structural proteins and enzymes and their kinetics; for lipids, the roles and types of lipid found in the body are considered; for carbohydrates, their roles including structural and metabolic are discussed; and the structure of nucleic acids is described). Then follows a description of the organization of the cell, including the plasma membrane and its components, and the intracellular organelles. Cell growth, division, and apoptosis are covered, as are the formation of gametes, and finally the principles of how cellular functions can be modulated by pharmacological agents through receptors and signalling pathways are discussed.


Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1467
Author(s):  
Anastasia Mozokhina ◽  
Rostislav Savinkov

This paper presents current knowledge about the structure and function of the lymphatic system. Mathematical models of lymph flow in the single lymphangion, the series of lymphangions, the lymph nodes, and the whole lymphatic system are considered. The main results and further perspectives are discussed.


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