enezymes Flashcards
(14 cards)
what are enzymes
globular proteins and the active site is specific and unique in shape due to the specific folding and bonding in the tertiary structure of the protein
intercellular and extra cellular enezymes
intracellular (located between cells) catalyse inside liver cells that break down hydrogen
extracellular ( located outside of cells) trypsin inside liver the small intestine that hydrolyses proteins
activation energy
the minimum amount of energy a reactant needs to react
when enzymes attach to the substrate they can lower the activation energy for the reaction to occur and therefore speed up reaction
Lock and key model hypothesis
This model suggest that the enzymes like lock and the other substrate is like a key that fits into it due to the enzyme specific territory structure. The enzyme active site is a fixed shape and so the substrate can collide and attached to the enzyme forming an enzyme substrate complex.
induced fit hypothesis
induced fit as when the enzyme active site is induced or slightly change shape to mould around the substrate when the enzyme substrate complex occurs it put strains on the point and therefore lowers activation energy
Factors affecting enzymes temperature
if the temperature is too low, there’s insufficient kinetic energy for successful collisions . as temperature increases the frequency of successful collisions increases
If the temperature is too high enzymes in nature, the active site changes shapes an enzyme complexes cannot form high temperature causes bond to break and theory structure alters causing a change in the shape of the active site
factors affecting enzymes pH
Too high or too low pH will interfere with the changes in the amino acids in the active site causing hydrogen bonds to break an altering tertiary structure and changing the shape of the active site and enzymes denature
factors affecting enzyme :substrate and enzyme concentration
If there is a low concentration of substrate, the reaction will be lower as they will be fewer collisions between the enzyme substrate
Increasing the substrate concentration will increase the rate of reaction
At low enzyme concentration there will be a lower rate of reaction
increasing the enzyme concentration will increase the rate of reaction as enzyme subject complexes will be more likely to form
competitive inhibitors
Competitive inhibitors are the same shape as the substrate and complementary in shape to the active site therefore they buy into active site which prevents substrate from binding and enzyme inhibitor complex is formed instead of enzyme-substrate complexes
Most competitive inhibitors are reversible
reversible and non-reversible
Reversible -inhibitor can be removed
Non-reversible - inhibitor cannot be removed
non-competitive inhibitors
Non-competitive inhibitors buying to the enzyme away from the active site to the allosteric site
This causes the active site to change shape and therefore the substrate can no longer bind and the rate of reaction is much lower
End product inhibition
The products of some reactions are reversible inhibits so the reactions can be controlled
If there is a lot of product present, it will inhibit the enzymes and cause the reaction to slow or stop which prevents resources from being wasted
co enzymes co factors and prosthetic groups
some enzyme controlled reactions require an additional non-protein molecule such as co-enzyme cofactor or a prosthetic group to catalyse a reaction
Coenzymes and cofactors
some reactions require atoms to be carried from the reaction to the next pathway reaction and some enzymes require a non-protein molecule to bind to the active site to make it complimentary to the substate.
These molecules are cofactors and enzymes. The difference is enzymes are organic molecules and cool factories are in organic molecules.
