Aresearcher synthesizes a new molecule called inhibitor x that inhibits the activity of phosphofructokinase (pfk), the enzyme that phosphorylates fructose 6-phosphate during glycolysis. inhibitor x competes with atp for binding to the pfk active site. the researcher determines that the michaelis-menten constant (km) with respect to atp is 40 μm. when 2 μm inhibitor x is added to the purified pfk reaction, the apparent km for atp increases to 48 um. calculate the dissociation constant of the pfk-inhibitor complex (k1).

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

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