What are index fossils and how are they used to determine the absolute age of sedi
mentary rocks

Index fossils are from species that only existed for a short period of time. they are found in rocky layers,  Trilobites and Graptolites are index fossils. A guide and zone fossil are used often to determine the age of the rock layer in which it is found.

This is what i found on google “when one phosphate group is removed by breaking a phosphoanhydride bond in a process called hydrolysis, energy is released, and atp is converted to adenosine diphosphate (adp). likewise, energy is also released when a phosphate is removed from adp to form adenosine monophosphate (amp).” i hope this you .

100%sorry if i’m wronghope this good luck: )