Question

a) Explain the enzyme kinetics using a labelled graph and corresponding point form notes that shows the impact of enzyme concentration changes.

Answer 1

Enzymes are typically proteins which boost the rate of chemical reaction without being used up. Enzyme kinetics graphs are used to display important imformation about enzymes. This are specific to particular substrate. Substrate binds the active sites on enzymes surface during reaction.

  

dp/dt the rate of product formation (mol/cm3/sec) k linear constant (1/sec) Vmax the maximum reaction the maximu rate (mol/cm3/sec) S the substrate concentration (mol/cm3) the enzyme concentration (mol/cm) к Michaelis-Menten constant (mol/cm3) kcat the catalytic constant (1/sec)

dp / dt = k * s

This graph show , how the reaction rate changes with increasing substrate concentration for reaction in the presense and absence of enzymes.

Vmax - - - Enzymes Reaction Rate (dp/dt) No Enzymes K1 K2 Substrate Concentration (S)

the rate of chemical reaction increases as the substrate concentration increases . enzymes can greatly speed up the rate of reaction . however enzymes become saturated when the substrate concentration is high . additionally , the reaction rate depends on properties of enzymes (k,kcat) and the enzymes concentration.

- - - - - - - - - Vmax Reaction Rate (dp/dt) + - - - - - - - - - - - - - Vmax - - - - Substrate Concentration (S)

when thw enzymes concentration is small, Vmax is much smaller. the reaction rate still increases with increasesing substrate conc, but level off at a much lower rate, by increasing the enzymes conc, the max. raction rate greatly increases.