Describe Lundegardh's Cytochrome Pump Theory .

Explanation

Lundegardh and Burstrom (1933) observe a correlation between respiration and anion absorption.When a plant is transferred from water to a salt solution the rate of respiration or salt respiration .Based on this observation
Lundegardh (1950 and 1954) proposed cytochrome pump theory which is based on the following assumptions:
(i)The mechanism of anion and catiuon absorption and different.
(ii)Anions are absorbed through cythochrome chain by an active process,cation are absorbed passively.
(iii)An oygen gradient responsible for oxidation at the surface of the membrane and reduction at the inner surface.
According to this theory,the enzyme dehydrogenase on inner surface is responsible for the foprmation of protons `(H^(+))` and electrons `(e^(-))`.As electrons pass outward through electron transport chain there is a corresponding inward passage of anions.
Anions are picked up by oxidized cytochrome oxide and are transffered to other members of chain as they transfer the electron to the next component.The throty assumes that cations `(C^(+))` move passively along the electron to the next component .Thr throy assumes that cations `(C^(+))`. move passively along the electrical gradient created by the accumulation of anions `(A^(-))` at the inner surface of the membrane.

(i)Cations also induce respiration.
(ii)Fails to explain the selective uptake of ions.
(iii)It explains absorption of anions only.