Cellular structure and function

The cerebral cortex is conventionally subdivided into four main regions that may be delineated by the sulci, or large clefts, termed the frontal, temporal, parietal and occipital lobes. These names are derived from the bones of the skull which overlay them. Each lobe may be further subdivided according to its cellular structure and composition. Thus Brodmarm has divided the cortex into approximately 50 discrete areas according to the specific cellular structure and function. For example, electrical stimulation of the strip of cerebral cortex in front of the central sulcus (see Figure 1.3) is responsible for motor commands to the muscles. This is termed the primary motor cortex and can be further subdivided according to which muscles are controlled in different parts of the body. 

Melarsoprol (frivalenf) and fryparsamide (penfavalent) are organic compounds confaining arsenic fhat bind to sulfhydryl groups in proteins, thereby affecting cellular structure and function. The action of arsenic is nonspe-... 

According to this scheme, practically all cellular structures and functions came later, and only RNA replication was present at the... 

Despite their immense diversity of sizes, shapes, and capacities, living cells are also remarkably similar. In fact, all modem cells are believed to have evolved from primordial cells over three billion years ago (see Special Interest Box 2.2). The common features of prokaryotic and eukaryotic cells include their similar chemical composition and the universal use of DNA as genetic material. The objective of this chapter is to provide an overview of cell structure. This review is a valuable exercise because biochemical reactions do not occur in isolation. It is becoming increasingly obvious that our understanding of living processes is incomplete without knowledge of their cellular context. After a brief discussion of some basic themes in cellular structure and function, the essential structural features of prokaryotic and eukaryotic cells will be described in relation to their biochemical roles. 

Like bacterial cells, unicellular eukaryotes may be subjected to widely varying environmental conditions that require extensive changes In cellular structures and function. For Instance, In starvation conditions yeast cells stop growing and form dormant spores (see Figure 1-4). In multicellular organisms, however, the environment around most cells Is relatively constant. The major purpose of gene control In us and In other complex organisms Is to tailor the properties of various cell types to the benefit of the entire animal or plant. 

J. Schaff, C.C. Fink, B. Slepchenko, J.H. Carson, L.M. Loew, A general computational framework for modeling cellular structure and function, Biophys. J. 1997, 73, 1135-1146. 

Temperature acclimation of plants is Icnown to be connected with the increased resistance of munerous cellular structures and functions (1,2). But if some authors think that adaptation is based on temperature induced conformational rearrangements of macromolecules (1), the others see its reason in a quantitative and qualitative changes observed in the protein complex of a cell (3) We believed (4), that both above mechanisms function in plants mutually supplemeting each other. It is assumed that a real contribution of each of them is dependent on the Intensity and duration of temperature effects, biological characteristics of the object and on occumpanying conditions (illumination, humidity, etc). 

Marguet M, Bonduelle C, Lecommandoux S. Multicompartmentalized polymeric systems towards biomimetic cellular structure and function. Chem Soc Rev 2013 42(2) 512-29. 

We have studied two of the three major kinds of biopolymers polysaccharides in Chapter 21 and proteins in Chapter 22. Now we will look at the third kind of biopolymer—nucleic acids. There are two types of nucleic acids deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DMA encodes an organism s entire hereditary information and controls the growth and division of cells. In all organisms (except certain viruses), the genetic information stored in DNA is transcribed into RNA. This information can then be translated for the synthesis of all the proteins needed for cellular structure and function. 

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