Question

Cells were treated with a chemical that inhibits the first step of the electron transport chain. How would this affect the levels of the inputs and outputs of the electron transport chain?

Answer 1

Treatment with a chemical that inhibits the first step of the ETC would likely increase levels of electron donors like NADH, decrease ATP production, and lead to accumulation of ADP in the cell.

Step-by-step explanation:

When cells are treated with a chemical that inhibits the first step of the electron transport chain (ETC), the levels of inputs, such as NADH and FADH2, would likely increase because they cannot donate their electrons to the chain. Concurrently, the outputs of the ETC, mainly ATP, would decrease as the passage of electrons through the chain is halted, preventing the pumping of protons across the mitochondrial membrane and thus inhibiting ATP synthesis by oxidative phosphorylation.

Regulation of the ETC relies not on feedback inhibition of specific enzymes, but on the balance of ADP and ATP concentrations within the cell. An increase in ADP levels signals greater ATP demand, activating the ETC for more ATP production. Conversely, high levels of ATP indicate lower demand, which slows down the ETC. Therefore, inhibiting the electron transport chain may lead to an accumulation of ADP since ATP is not being synthesized efficiently, potentially signaling the cell to attempt to increase ETC activity, but this effect would be nullified by the inhibitor present.

Answer 2

The levels of inputs and outputs will be negatively affected

Please find the detailed explanation below

Step-by-step explanation:

The electron transport chain consists of a series of molecules that transfers electrons to one another in a group called COMPLEXES. The major aim of the ETC is to build a proton gradient needed for the synthesis of ATP. The first step in the ETC is as follows:

The process of ETC starts when two electron carriers/donors viz: NADH and FADH2 transfers their electrons to COMPLEX I. If this does not occur, the ETC cannot function. Hence, in a case where cells were treated with a chemical that inhibits the first step of the electron transport chain, the input and output (ATP) will be greatly affected in the sense that other inputs will not be used or the output will not be produced.