The ${\mathbf{\text{O}}}_{\mathbf{2}}$-consumption curve of a dilute, well-buffered suspension of mitochondria containing an excessof$\mathbf{\text{ADP}}$and ${\mathbf{\text{P}}}_{\mathbf{i}}$takes the following form:

Sketch the curves obtained when (a) amytal is added at time $\mathit{t}\mathbf{=}\mathbf{1}$ and

(b) amytal is added at $\mathit{t}\mathbf{=}\mathbf{1}$and succinate is added at .

The oxygen consumption curve when amytal is added at time t=1 in a well-buffered solution of mitochondria having an excess of ADP and Pi is shown in the diagram below.

Figure 1 shows the oxygen consumption curve.

(a) Amytal was introduced at time t=1.

(b) Amytal was added at time t=1 while succinate was added at time t=2.

Explanation: Complex l, a crucial supplier of electrons to the ATP-producing electron transport cycle, is inhibited by amytal. As a result, the amount of oxygen consumed decreases.

The oxygen consumption curve in a well-buffered solution of mitochondria with an excess of ADP and Pi when amytal is added at time t=1 is shown in the diagram below.

Figure 1 shows the oxygen consumption curve.

(a) Amytal was introduced at time t=1.

(b) Amytal was added at time t=1 while succinate was added at time t=2.

Explanation: Succinate enters the electron transport chain's complex II after bypassing the amytal barrier in complex I. It restores the electron transport chain by contributing electrons to complex III.