2.1.3 Flashcards
What protein structure do enzymes have?
tertiary
What conditions disrupt enzymes?
high temperatures
extreme pH
What do enzymes control?
the rate of chemical reactions
What type of proteins are enzymes?
globular proteins
What are enzymes?
biological catalysts
used in metabolic reactions
lower Ea
not used up in the reaction
What are coenzymes?
organic ions
not permanently bound to enzyme
needed to activate the enzyme produce the specific complimentary shape to the active site
take part in the reaction
What is a cofactor?
inorganic ion
permanently bound to the enzyme
What are catabolic reactions?
these release energy that is used to drive chemical reactions
break down larger molecules into simpler molecules
What are intracellar reactions?
these are reactions that occur within a cell
What are extracellular cells?
these are reactions that occur outside of the cell
What does the enzyme substrate complex break down to form?
product and an enzyme
What is the lock and key hypothesis?
Enzyme = lock
Substrate = key
Substrate is complimentary and specific to the enzyme’s active site
active site is a certain shape and does not change shape
What is the induced fit model?
the active site changes shape slightly to accommodate the substrate
Which enzyme model is more correct?
induced fit model
What affect does temperature have on the rate of a reaction up until the optimum temperature is reached?
as temp inc
enzyme + substrate gain KE
more sucsessful collisions between substrate and active site
more enzyme-substrate complexes form
What effect does the temperature have on the rate of a reaction after the optimum temperature has been reached?
after the optimum is reached
due to gaining lots of KE
molecules in enzyme move around more
this breaks hydrogen and ionic bonds
denatures enzyme
active site is no longer complimentary or specific in shape to substrate
tertiary structure of enzyme changes
fewer enzyme substrate complexes form
What impact does the low pH have on enzymes?
At low pH the H+ attract the negative R groups in the hydrogen and ionic bonds
causing he hydrogen and ionic bonds to break
this changes the tertiary structure of the enzyme
the active site is no longer complimentary or specific in shape to the substrate
there are fewer enzyme-substrate complexes formed
What impact does a high pH have on he rate of a reaction?
at a high pH, the OH- attracts the positive R groups in the hydrogen and ionic bonds
causing the hydrogen and ionic bonds to break
this changes the tertiary structure of the enzyme
the active site is o longer complimentary or specific in shape to the substrate
there are fewer enzyme-substrate complexes formed
What effect does substrate concentration on the rate of a reaction?
as the substrate concentration increases
there are more sucsessful collisions between the active site and the substrate
there are more enzyme substrate complexes being formed
until alla ctive sites are saturated
and the enzyme concentration becomes the limiting factor
What effect does enzyme concentration have on the rate of a reaction?
as enzyme concentration increases there are more sucsessful collisions between the active site and substrate
there are more enzyme substrate complexes formed
until all the substrate is used up
and the substrate concentration becomes the limiting factor
What is a coenzyme?
organic ions
not permanently bound to the enzyme
needed to activate the enzyme
produce the specific shape of the active site
take part in a reaction
What is a cofactor?
inorganic ion
permanently bound to enzyme
needed to form a haloenzyme
produce the specific shape of the active site
do not take part in the reaction
What is a prosthetic group?
non-protein group that is permanently bound to an enzyme
What is the cofactor for amylase?
Cl-
What is the prosthetic group for carbonic anhydrase?
Zn2+
What is a source of coenzymes?
vitamins
What is a competitive inhibitor?
substrate competes with the inhibitor
both substrate and inhibitor have a complimentary specific shape to the active site
will be fewer enzyme substrate complexes
more substrate reduces the chance of the inhibitor getting into the active site
What is a non-competitive inhibitor?
this inhibitor fits into the allosteric site / away from the active site
this changes the shape of the active site
substrate is no longer complimentary to the active site
there will be fewer enzyme-substrate complexes
On a graph with the uninhibited, competitive and noncompetitive inhibitors, what happens to the compeititive inhibitor?
more substrate added the more it will outcompete the uninhibited geaph
Why does the non-competitive inhibitor plateau lower?
non-reversible binding of the inhibitor changes the shape to the active site
What does the end product do in end product inhibition?
end product bids to the enzyme away from the active site preventing it from binding to any more substrate
What is an inactive precursor?
an inactive enzyme that can be made active
