Enzymes Flashcards
Enzymes are what type of biomacromolcule?
Proteins
Define enzymes
Protein molecules that catalyse chemical reactions
What substance is energy dervied from
ATP
Chemical reaction of ATP
ATP —–> ADP + Pi
Define anabolic reactions
Form larger compounds from smaller units
Anabolic reactions are also……
endergonic
What do engergonic reactions require?
energy
Define Catabolic reaction
Break down larger compound in a smaller one
Releases energy
What are catabolic reactions also……
exergonic
What do exergonic reactions release?
energy
Define Activation energy
The minimum energy required for a reaction to occur
How do catalyst work
Increases the rate of reaction by lowering the activation energy
Explain enzyme specifiity
They are highly specfic as each enzyme acts on one substrate, tthis is due to the specifc shape of the active site on the enzyme matching the shape of the substarte molecule
what is an enzyme substrate complex
When the substrate is bound to the enzymes active site
What do enzymes and substartes need to be?
Complementary
What are the molecules enzymes work on
Substrates
Explain the lock and key theory
States that the active site fits exactly onto the substarte that it acts on
Explain the induced fit model
States that the active site is slightly altered to match the substrate (enzyme changes shape)
Explain what cofactors are and their role
inorganic or organic compunds that are nesscary to pbe present for the function of particular enzymes
Define coenzymes
Organic factors that are nesscary for the action of certain enzymes. Changed in the reaction they take part in and cannot be used again
What do all enzymes end in
ase
Define competitive inhibitors
Compounds that compete for the active site and may mimic it, thus ceasing the enzyme from working as the substrate can no longer bind there
Define Non-competiive inhibitors
Chemical compounds that bind to an allosteric site and alter confirmation of the enzymes active site so that the reaction cannot proceed.
What happens if the temperature that the enzymes environment is in is too low
- Molecule activity is lower and moving slower
- Hence colliding with substrate molecules less frequently
- Enzyme substrate complexes are less likely to form
- Therefore reaction rates fall
What happens if the temperature that the enzymes environment is in is too high
- Heat will begin to break down the bonds in the enzyme
- Cause conformation shape to be change and the active site to be destroyed, enzymes have become denatured
- Enzyme-substrate complexes can no longer form as they are no longer complementary
- Therefore reaction rates fall
What does a change in pH do to the enzyme?
Causes a change in the enzymes active site
-However can be reversed
Explain how enzyme concentration can affect the rate of the reaction
If the concetration of the enzyme is increased so is the rate of the reaction as more enzyme subtrate complexes are being formed
Explain the increase of subtrate concentration
- Initially increase the rate of reaction
- Untill all of the active sites are occupied/saturated
- When this happens the rate becomes constant
