Flagella growth

The fact that experimental results (see below) give some grounds for belief that conditions exist for Chlamydomonas in which Eqs. (10) and (12) describe approximately the kinetics of flagella growth should not blind us to the complex realities of the situation. 

Figure 9.30 Flow diagram of the energy chain from food to essential processes in human life. The ATP utilised by the NayK ATPase maintains the ion distribution in nerves that is essential for electrical activity and, in addition, maintains neurotransmitter synthesis, both of which provide communication in the brain and hence consciousness, learning and behaviour (Chapter 14). ATP utilisation by myosin ATPase is essential for movement and physical activity. ATP utilisation by the flagellum of sperm is essential for reproduction and ATP utilisation for synthesis of macromolecules is essential for growth.

Organism bd bos Growth on sugars 2,3-Butanediol Acetoin Flagellum T3SS Production of organic acids... 

For the present purpose it is convenient to focus attention on the structurally identifiable axoneme and to neglect the membrane and the matrix material. The growth of a flagellum will depend on the synthesis of a number of species of protein chain, their incorporation into one or more types of subunit, and the subsequent assembly of these subunits (at the correct site of sites) into the axoneme components. Thus the various proteins must be made in the appropriate quantities and be available when and where they are required. The final growth curve, of which examples are given subsequently, is the result of these and possibly other processes which may be regarded as a series of coordinated reactions for which in the usual way energy will be required. 

Fig. 25. Diagram of regenerating flagellum in which L represents the supposed maximum length. L represents the length attained after time t from the initiation of growth.

It would be tedious to discuss the many reasons why such considerations should not apply to the mechanism of growth of an actual flagellum, and one should exercise caution in comparing theoretical and experimental data, especially when the two do not fit except under certain experimental eonditions. However, it is perhaps not too optimistic to presume that further study may reveal a situation in whieh one rate-limiting process may be shown to dominate. Whether this is so or not, there seems no escape from detailed kinetic studies if we are to understand the formation and control of the flagellar organelle. 

Removal of nitrogen by transferring cells from growth medium to liquid NFM was found to cause a fairly rapid increase in mean flagellum length. From a value of 8.21 jam the mean length had increased to 10.50 jam after 4 hours and 11.77 jam after 24 hours. On other occasions mean lengths of 11.44 jam, 10.74 jam, and 10.93 jam were obtained after... 

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