You are working on a new culture from a salt rich lake and s

You are working on a new culture from a salt rich lake and suspect that its respiratory chain generates a sodium motive force rather than a proton motive force, to be used to make ATP via the membrane bound ATPase. You start with cells in resting state, with equal concentrations of sodium ions and protons in and out of the vesicle. You provide ADP+Pi and at time zero, energize the intact electron transport chain with NADH. You test for proton and sodium motive force, using ionophores specific to each. Prior to addition of NADH you provide:

1. DCCD (affects H+ and Na+ driven ATPases)
2. SF6847 (a H+ specific ionophore
3. ETH157 (a Na+ specific ionophore )
4. Negative control: no ionophore or DCCD added.

The left panel shows the outcome of the 4 treatments if the ATPase is driven by a proton motive force, and the right pabel if by a sodium motive force. Match the 4 treatments with the 4 symbols.

Solution

The dark square represents DCCD treatment

the dark triangle represents negative control no DCCD or ionophore added

the dark circle represents treatment with ETH157- Na specific ionophore and

the light triangle represents treatment with SF6847- H+ specfic ionophor.