Membranes are barriers for hydrophilic molecules and ions because of the hydrophobic core of the phospholipid bilayer. A membrane or is a two-dimensional, spherical particle separating an inside compartment from an outside compartment. In addition to lipids, a membrane contains that control the transport of hydrophilic and charged, small and large molecules into and out of the cell and intracellular organelles. The importance of the lipid bilayer membrane is its ability to function as an . This enables charge separation and thus the storage of electro-chemical energy in form of ion gradients. One example is the proton motif force (pmf or proton gradient) discussed in sections on oxidative phosphorylation and photosynthesis. Membrane proteins that serve as conductors are used by the cell to extract small quanta of this energy for synthesis or signaling mechanisms. Two examples are ATP synthesis and action potentials, respectively.
Generally, peptides consisting of fewer than 50 amino acids are peptides and those with more are called proteins. Peptides are hydrophilic (lipophobic).
The sclerotia contain a large number of biologically active alkaloids, as well as amino acids, carbohydrates, lipids, and pigments, and, when the sclerotia are consumed by man and animals, toxicosis develops, called ergotism.
In synchronously dividing Tetrahymena cells (Iwahashi et al., 1982), the incorporation of radioactive amino acids, thymidine, and uracil into protein, DNA, and RNA, respectively, was achieved by nearly the same concentration of T-2 toxin.
NIV inhibited poly-U, poly-A, and poly-C directed incorporation of phenylalanyl-tRNA into phenylalanine without affecting the activation of amino acids.
They reported that NIV produced a dose-dependent inhibition of incorporation of several amino acids into protein in rabbit reticulocytes (Ueno et al., 1968) and Ehrlich ascite tumour cells (Ueno & Fukushima, 1968).