chap 4- enzymes Flashcards
What are enzymes
Catalysts in biological pathways that can build molecules and speed up reactions.
Why are enzymes essential for biological reactions
The reactions would be slow without them
What is the key structural feature of enzymes
Active site which is where the enzyme interacts with substrate to catalase a reaction
What is enzyme specific
Each enzyme can only catalase a particular reaction or a specific set of reactions
What does the lock and key model assume
Active site is rigid and cannot change
What is the lock and what is the key in the lock and key model
Enzyme is the lock. Substrate is the key.
What does the induced fit model assume
Active site is flexible and can change shape to fit around substrate
What is metabolism
A collection of all the biochemical reactions that occur in living years
What is catalytic power
An enzymes ability to increase the rate of biochemical reactions compared to the reaction occurring without a present enzyme
What is catabolism
Breaking down molecules that releases energy. Cellular respiration
What does exergonic mean
Released energy
What is anabolism
Building up molecules that required energy. Photosynthesis
What is activation energy
Energy required to go from reactants to products
What is inhibition
The binding of another component and change in the shape of a molecule that prevents molecule from functioning
What is reversible inhibition
Hydrogen bonds being broken. Temporary
What is irreversible inhibition
Covalent bonds are strong so hard to break. Permanent
What is competitive inhibition
Two different molecules trying to bind to same spot. Inhibitor has similar shape so prevents substrate from accessing active site
What is non-competitive inhibition
Inhibitor binds to Alister. Site which distorts the enzymes shape so substrate can’t bind to it and usually reaction can’t be catalysed
what do all enzymes contain
a protein backbone
what are cofactors
additional non-protein components that enzymes have that are important contributors to both the activity and stability of an enzyme.
why are cofactors needed
for enzymes to function properly
what are coenzymes
small, non-protein organic cofactors
where do coenzymes commonly bind
to the active site of an enzyme. but this isnt always the case
what do coenzymes play a crucial role in
transferring functional groups in enzyme-catalyzed reactions
what is the unloaded form of a coenzyme
it has the ability to accept a proton, electron or chemical group.
what is the loaded form of a coenzyme
the coenzyme that was once unloaded has accepted its considered loaded
which of ATP and ADP is loaded and unloaded
ATP is loaded
ADP is unloaded
what does ATP stand for
adenosine triphosphate
what does ADP stand for
adenosine diphosphate
what is a hydrolysis reaction
turns ATP into ADP
what does a hydrolysis reaction consume
water
is a hydrolysis reaction exergonic
yes
what is the key role of loading/unloading NADH and NAD+
to carry a hydrogen and electrons to the mitochondria
what does NADPH do
carries electrons and hydrogens in photosynthesis
what does FADH2 do
carries hydrogens and electrons in cellular respiration
