Enzymes

• what is an enzyme

  a biological catalyst
• how does an enzyme catalyse a reaction

  by putting pressure and strain on the bonds in the substrate so less energy is needed to overcome them and the activation energy is lowered
• what is the induced fit model

  when the substrate is a slightly different shape to the enzymes active site so it must change shape slightly to bind etc the substrate and form an enzyme substrate complex. as the enzyme changes its shape it mold with the substrate it puts pressure on the bonds in he substrates which weakens them so lowering the activation energy
• what is competitive inhibition

  when the inhibitor has a similar shape to the substrate so ends to the enzymes active site temporarily therefore not allowing the substrate to bind in order to from an enzyme substrate complex so therefore less product is made. if there are many substrates they can knock the inhibitor out of place
• What is non-competitive inhibition?

  when the inhibitor binds to the allosteric site of an enzyme which causes the tertiary structure of the enzyme to change and so changes the enzymes active site so the substrate is no longer complimentary and can not bind to from an enzyme substrate complex. this is a temporary change so can reduce and stop product being formed
• How does temp affect enzymatic activity. before(A) and after(B) optimum

  A -As temp rise rate of reaction also ruses, the enemy and substrate gain kinetic energy so there are more successful collisions happening and more complexes are formed so there is more product.

  B - Temp has increased past optimum so the enzyme has lots of kinetic energy which causes the bonds in it to break causing the active site to denature so the substrate can non longer bind to form an enzyme substrate complex so less product is formed
• How does ph affect enzymatic activity. before(A) and after(B) optimum

  A- ph is too acidic so there are too many H+ ions that interfere with the bonds at thee active site which causes it to change shape to substrates can't bind to form an enzyme substrate complex so less product is formed.

  B - ph is too acidic so there are too many OH- ions that interfere with the bonds at thee active site which causes it to change shape to substrates can't bind to form an enzyme substrate complex so less product is formed.
• How does enzyme concentration affect enzymatic activity. before(A) and after(B) optimum

  A - as enzyme concentration increases so does rate of reaction as there was is an increasing amount of enzymes to bind with the substrates available and form enzyme substrate complexes so more product is formed.

  B - the substrate has become the limiting factor as the enzyme concentration has increased so much it is in excess
• How does substrate concentration affect enzymatic activity. before(A) and after(B) optimum

  A - as substrate concentration increases so does rate of reaction as there was is an increasing amount of substrates to bind with the enzymes available and form enzyme substrate complexes so more product is formed.

  B - the enzyme has become the limiting factor as the substrate concentration has increased so much it is in excess
• what is vmax

  when all active sites are fulled with substrates es - the max rate of reaction
• What is competitive inhibition?