SALT ABSORPTION AND METABOLISM 



89 



centrations which do not affect oxygen absorption (Fig. 32a) 

 supports the view that active transport is more closely linked to 

 protein synthesis than to some other aspects of metabolism. Chlor- 

 amphenicol, at the concentrations used, did not interfere with proto- 

 plasmic streaming in red beet or Elodea cells and since streaming 

 probably depends on the folding and unfolding of protein chains it 

 is unlikely that salt absorption occurs by a mechanism such as that 



140 



Fig. 32 (a). Effect of chloramphenicol on salt absorption 



a. Uptake of sodium ions ( — ) and chloride ( ) from 001 M sodium chloride 



(+) and 001 M sodium chloride plus chloramphenicol (2g per 1.) (O) by 



washed red beet tissue at 25 °C. After 48 hr, the disks were transferred to 



alternative media as indicated (from Sutcliffe, 1960); 



proposed by Goldacre and Lorch (1950) (Fig. 12d, p. 43). It is more 

 likely to be related to a cycle of ion binding and release accompanying 

 the synthesis and hydrolysis of protein (cf. Fig. 31a). In this case, 

 salt transport may be a general property of protein associated with 

 membranes. Membrane synthesis, folding and vesiculation may be 

 involved in transferring the ion-protein complexes from place to 

 place, within the cytoplasm, and in depositing the free ions finally 

 within vacuoles (Fig. 12 e, p. 43; see also Chapters 6 and 10). 



A feature of cells of storage tissues is that when first cut from 

 the dormant organ they are incapable of accumulating salt actively, 



