ch 5 Flashcards
define enzymes [3]
-they are protein molecules
- act inside the body as a biological catalyst , to speed up the chemical reactions
-they act on substrates to turn them into products
define active site [2]
a depression on the surface of the globular (ball shaped) protein molecule (enzyme)
-it is where the substrate molecule binds
how does enzyme works [3]
-substrate binds to the active site of the enzyme
-enzyme-substrate complex is formed
-enzyme breaks down the substrate into products which are released away from the active site
factors affecting enzyme activity [4]
-temperature
-PH
-conc of enzymes
-conc of substrate
what is the effect of temperature on enzyme activity [9]
-as temp increases , enzyme activity increases , till enzyme reaches optimum temperature
-as temp rises, kinetic energy of enzyme and substrate increases
-they move faster, so more frequent collisions
-more fitting of substrate to enzymes
-more release of product
-after optimum temperature as temp increases the enzyme activity decreases till reaction stops
-this is because enzymes are proteins and proteins are denatured by high temp which breaks down the hydrogen bonds (which keep the shape of the enzyme)
-so enzyme loses its shape , loses its active site
-permenant irreversible damage of the active site, cant fit anymore substrate so reaction stops
define optimum temperature
the best temperature where enzyme works
effect of PH on enzyme activity [3]
-as we go nearer to optimum PH, enzyme activity increases
-as we go further away from the optimum PH , the enzyme activity decreases
-PH changed breakdown the ionic bonds that maintain the shape of the enzyme , so lose its active site and cant fit substrate anymore - denatured.
define optimum PH
the PH at which an enzyme works best
variables in every experiment [3]
-independent varible -> factor we change
-dependent variable -> factor we measure
-key variable -> factor we fix
why enzymes are important to all living organisms
they help in chemical reactions to sustain life
