Chapter 19, Problem 5P

(a)

Summary Introduction

To explain:

The reason behind the rotenone being lethal to some insects and fishes.

Introduction:

There are several agents that intervene with oxidative phosphorylation. Depending on the type of interference they are classified as the agents that inhibit transfer of electron, agents that inhibit ATP (adenosine triphosphate) synthase, agent that uncouple phosphorylation from electron transfer and agents that inhibit ATP-ADP (adenosine diphosphate) exchange.

(b)

Summary Introduction

To explain:

The reason behind antimycin A being poisonous.

Introduction:

Agents that inhibit the transfer of electrons are known as inhibitors of electron transport chain. Some of the examples of inhibitors are rotenone, antimycin A, amytal, piericidin A, cyanide, and carbon monoxide.

(c)

Summary Introduction

To explain:

Whether rotenone or antimycin A is more poisonous.

Introduction:

Rotenone and antimycin both are inhibitors of electron transport chain. Rotenone inhibits the flow of electron to complex I and antimycin inhibits the flow of electron from complex II to complex III. The potency of inhibitors depend on the complex which is blocked.