Feed-forward activation in a theoretical first-order biochemical pathway which contains an anticipatory model
✍ Scribed by Jeff Prideaux
- Book ID
- 104622240
- Publisher
- Springer
- Year
- 1996
- Tongue
- English
- Weight
- 681 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0001-5342
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✦ Synopsis
This paper explores the consequences of the theoretical forward activation enzymatic pathway A 0 ~ A 1 ~ A 2 ~ A 3 where E 1 convents A 0 to A1, E 2 converts A 1 to ,42 and E 3 converts A 2 to A 3. Ao~ which is environmentally determined, also serves to activate (or modulate) the activity of E 3 in such a way as to keep the concentration of A 2 ([Az]) constant at a particular set-point value. For mathematical simplicity, first order rate kinetics are used where/q, k 2 and k a are the rate constants for El, E2, and E 3 respectively. It is shown that if k a is modulated appropriately so as keep [A2] at the setpoint value with a changing upstream [A0] , then the modulation of k a must be anticipatory of the dynamics of the biochemical pathway. In other words, the rate of change of k3, will be a function of [A0], kl, k2, ka, and the set-point value of [A2]. If the modulation of k a does not perfectly model (anticipate) the reaction pathway of which it is a part, then the actual [A2] will deviate from the setpoint value. This type of anticipatory feed-forward activation may represent an important aspect of biological organization.