When lead acts as a poison, it can do so by either replacing another ion (such as zinc) in the active site of an enzyme or reacting with cysteine side chains to form covalent bonds. which of these is irreversible and why?

Aperson travels 35 km in 0.4hrs, followed by 53 km in 0.6 hr. what is the average speed

What do transitional fossils best support?

Abeaker of water was heated and then placed on a bench in the laboratory. the water cooled until it was the same temperature as the air in the laboratory. which of these explains the mechanism by which the water cooled? a. heat energy was transferred from the water to the air. b. water molecules from the water formed warm water currents. c. the water molecules absorbed energy from the molecules in the air. d. the water released radiation until it contained no heat energy.