| Popis: |
1. 1. Etiolated pea stems contain a powerful ascorbic acid oxidase, which does not sediment at 10,000 × g . 2. 2. The enzyme needs an O 2 tension of 0.13 atm. for half-saturation, is unaffected by CO, and is more active per unit length in growing than in non-growing internodes. 3. 3. The intact tissue, however, consumes oxygen at a rate only one-fortieth as great as that for which the ascorbic oxidase could account, and furthermore at least 80% of its oxygen consumption is light-reversibly inhibited by CO. 4. 4. It is deduced that the ascorbic oxidase does not function as a terminal oxidase in the intact cells, but that the respiration is mainly mediated by cytochrome oxidase. |
