SB1- Key Concepts Flashcards
Rate of reaction=
1000/time
Unit= s-1
The substrate is the molecule that is
Changed in the reaction
What is an active site
The part of an enzyme that joins to the substrate to catalyse the reaction
Enzymes have a ________ for their substrate
High specificity, only work for one substrate
What is the lock and key mechanism/induced fit
Where the substrate fits into the active site to catalyse the reaction. If the shape is wrong it won’t work
What are enzymes (2 parts)
Biological catalysts that speed up useful chemical reactions in the body
and reduce the need for higher temperatures
What is a catalyst
A substance that increases the rate of reaction without it being changed or used up
Describe the effect of increased temperatures on rate of reaction, enzyme-catalysed.
Higher temp = increases ror at first
Too hot = bonds in enzyme break=denatured active site=substrate won’t fit
All enzymes have an optimum temp, commonly body temp
Describe the effect of pH on ror in enzyme-catalysed reactions (include example).
Too high or low pH =denatured active site = lower ror
Optimum commonly pH 7 but pepsin in stomach is pH 2 hence acidic conditions there
Describe the effect of substrate concentration on ror in enzyme-catalysed reactions
Higher the subcon = higher ror as more likely an e and s will meet
But this isn’t always true as active sites will fill up so added for sub will make no difference
Amylase is what and what does it do
Enzyme that catalyses the breakdown of starch to maltose
How do you detect starch
Use iodine, if present the solution will change from browny-orange to blue-black
In the amalayse pH experiment what can you use instead of a Bunsen and why is that beneficial
A water bath to control temperature (35°c)
In the amylase pH experiment what goes in the test tube
3cm3 of amalayse solution and 1 cm3 of buffer at pH 5
In the amalayse pH experiment how long is the boiling tube in the beaker of water
5 minutes
