enzymes and digestion Flashcards
catalyst definition
substance that speeds up the rate of reaction without being changed or used up
what do enzymes reduce
reduce the need for high temp and we only have enzymes to speed up the useful chemical reactions in the body
what are enzymes made up of
theyre all large proteins and all proteins are made up of chains of amino acids. these chains are folded into unique shapes which enzymes need to do their jobs
whats active site
every enzyme has active site with a unique shape that fits onto the substance involved in a reaction. for the enzyme to work the substrate has to fit into its active site.
if the substrate doesn’t match the enzymes site what wont happen
the reaction won’t be catalysed
enzymes need the right conditions e.g. temp whats this called
optimum condition
how does temp effect enzymes
a higher temp increases the rate at first but it gets to hot some of the bonds holding the enzyme together break. This changes the shape of enzymes active site so substrate wont fit anymore the enzyme is said to be denatured
enzymes have a temp which they are most active whats this called
optimum temp
how does pH affect enzymes
if its to high or low the pH interferes with the bonds holding the enzyme together. this changes the shape of the active sit and denatures the enzyme
why can enzymes be described as biological catalysts
because they increase speed of a biological reaction without being changed or used up in the reaction
true or false all enzymes work best at pH7
false
what is the name of the part of an enzyme that binds to the substrate
active site
give steps to investigating the effect of pH on amylase
- put a drop of iodine solution into every well of a spotting tile
- place bunsen burner on heat proof mat and a tripod and gauze over the bunsen burner. put beaker of water on top of tripod and heat the water until its 35degreecelcius
use a syringe to add 1cmcubed of amylase solution and 1cmcubed of buffer solution with a pH of 5 to boiling tube. using test tube holders put boiling tube into beaker of water and wait for 5 mins
use a syringe to add 5cmcubed of starch solution to the boiling tube
mix contents of tube then start timer
use continous sampling to record how long it takes for the amylase to break down all of the starch. when iodine solution reamins browny orange no starch present
how to calculate rate
rate = 1000/time
what 2 ways is food broken down
mechanical digestion - includes our teeth grinding down food and stomach churning up food
chemical digestion - where enzymes help to break down food
