Enzymes Flashcards
(20 cards)
what is an enzyme
biological catalysts the speed up rate of chemical reaction happening inside our body. They are globular protein with a specific tertiary structure
enzymes key feature
-biological catalyst
-globular protein
-metabolic pathway
what is extracellular protein
some are secreted from cell and are made and act their substrate they digest larger molecules
what is a intracellular protein
in any cell within the organelle there are over 1000 metabolic reaction all with enzymes to catalyst them
what is a co-factor
a substance that has to be present to ensure that an enzyme catalysed reaction takes place at a appropriate rate
what is the lock and key method
This model suggests that the substrate fits into the enzyme’s active site in the same way in which a key fits into a lock. The shape of the substrate and the active site are perfectly complementary to each other
what are the stages of lock and key
The substrate binds to the enzyme’s active site, forming an enzyme-substrate complex (ES complex).
The enzyme converts the substrate into product, forming an enzyme-product complex (EP complex).
The product is released from the enzyme’s active site.
what is the induced model
the shapes of the enzyme’s active site and its substrate are not exactly complementary, but when the substrate enters the active site, a conformational change (change of shape) occurs which induces catalysis.
what are the stages for induced fit
The substrate enters the enzyme’s active site, forming an ES complex.
The enzyme undergoes a conformational change which causes the conversion of substrate into product, forming an EP complex.
The product is released from the enzymes active site.
what factor can affect the rate of reaction
-enzymes concentration
-substrate concentration
-temperature
-Ph
how can enzyme concentration affect rate of reaction
as it increases the RoR increases
more active site available for substrate to bind to so there is more frequent collision happening so there will be more formation of enzyme-substrate complexes.
how does substrate concentrations affect RoR
As substrate concentration increases, the rate of reaction increases
since there are more substrate molecules to fill the enzyme’s active sites. There will
be more frequent collisions so more formation of ES complexes. At some point a ‘saturation’ point is reached
how does temperature affects
low temperature = slow rate of reactions
as temperature increase kinetic energy also increase so more frequent collisions forming more enzyme substrates complexes
high temperature= enzymes denature
how does Ph affect RoR
each enzymes will have there optimal temperature
Deviations from the optimum pH change the charge on the enzyme, which affects ionic bonding within its structure. Deviations in pH also break hydrogen
bonds. This causes it to change shape and become denatured
what is temperature coefficient (Q10)
rate at a higher temperature / rate at a lower temperature
what is coenzymes
organic molecules
These work by directly participating in the reaction so are chemically altered by the end of the reaction. They often carry
chemical groups between different enzymes.
what is a competitive inhibitor
which bind to the active site of the enzyme, blocking the substrate from binding - they compete with the substrate for access to the enzyme’s active site.
how can the effect of the competitive inhibitors be reduced
increasing substrate concentration.
If there is way more substrate compared to
inhibitor then the substrate is much more likely to collide with the enzyme’s active site.
what is a non-competitive inhibitor
which bind to a site on the enzyme away from its active site. This region is known as its allosteric site.
what is End-product inhibition
is when the final product in a metabolic pathway inhibits an enzyme that
acts earlier on in the pathway
End-product inhibition is a good way of regulating metabolic pathways and controlling the amount of product produced. It is reversible, so when the product begins to drop, the enzymes will be able to function again to make more of the product.
