REACTIVITY OF CHLOROPHYLL a/b-PROTEINS AND MICELLAR TRITON X-100 COMPLEXES OF CHLOROPHYLLS a OR b WITH BOROHYDRIDE

The reaction of several plant chlorophyll-protein complexes with NaBH4 has been studied by absorption spectroscopy. In all the complexes studied, chlorophyll b is more reactive than Chi a, due to preferential reaction of its formyl substituent at C-7. The complexes also show large variations in reactivity towards NaBH4 and the order of reactivity is: LHCI > PSII complex > LHCII > PSI > P700 (investigated as a component of PSI). Differential pools of the same type of chlorophyll have been observed in several complexes. Parallel work was undertaken on the reactivity of micellar complexes of chlorophyll a and of chlorophyll b with NaBH4 to study the effect of aggregation state on this reactivity. In these complexes, both chlorophyll a and b show large variations in reactivity in the order monomer > oligomer > polymer with chlorophyll b generally being more reactive than chlorophyll a. It is concluded that aggregation decreases the reactivity of chlorophylls towards NaBH4 in vitro, and may similarly decrease reactivity in naturally-occurring chlorophyll-protein complexes

'I was just the boy around the place': what made apprenticeships successful?

his article seeks to add to current policy and debate on apprenticeships and youth transitions more widely by reflecting back upon the historical experience of the apprenticeship model. The research comprises in‐depth interviews with 30 people who undertook apprenticeships in a range of trades in Great Britain in the period 1944–1982. The discussion focuses upon the socialisation aspects of apprenticeship and concludes that a key feature of good apprenticeships in the post‐ war period was that they offered a sheltered and extended period in which the young person was able to grow up and become job‐ready. Reconstructing the social, industrial, familial and community conditions that made this possible is very difficult in the contemporary period, although further work in oral history has considerable potential