Effect of PH and temperature on enzyme activity

What are enzymes

Are biological catalyst that speed up chemical reactions without being changed or used up

-They are large proteins made up of chains of amino acids

-These chains are folded into have shapes

What does enzyme have

A active site with a unique ship that fits onto the substrate

Why are enzymes specific for one reaction

As substrate has to fit into its active site. If substrate does not match the enzymes active site then the reaction won’t be catalysed

What’s the lock and key theory

Where enzymes are specific. The substrate must fit perfectly into the active site l

How does temperature affect an enzyme reaction

As we increase the temperature the activity of the enzyme increases(the reaction gets faster)

-This is beacsue as temperature increases the enzyme and substrate are moving faster so there are more collisions per second between the substrate and the active site

What’s the optimum temperature of an enzyme

Where the enzyme is working at the fastest possible rate

-At this point there is maximum frequency of successful collions between the substrate and the active site

What’s the optimum temperature for enzymes

37 degrees which is human body temp

What’s happens if we increase the temperature past optimum

-The activity of the enzyme rapidly decreases to zero this is beacsue at high temperatures the enzyme molecule vibrates and some of the bonds holding enzyme breakers causing the shape of the active site to change.

-This means the substrate can’t fit into the active site. So the active site is denatured.

How does PH affect enzyme activity

If it’s too high or low the ph interferes with the bonds holding enzymes together which changes shape of active site and denatures enzyme

What’s the optimum Ph

Where activity is at its maximum.

-This is normally 7 degrees but notate as pepsin enzyme works best at Ph2

What happens if we make Ph more acidic or more alkaline

Then the activity drops to zero as the active site denatures if conditions aren’t right

Which enzyme is each point in graph

Far left- Enzyme that works best in acidic ph. So could be a protease enzyme in stomach

Far right-Enzyme works best at alkaline ph. Could be an enzyme related by pancrease into small intestine(lipase)