1.5 Flashcards
(18 cards)
structure of enzymes, how is it unique
globular proteins
v specific shape bc of 1’/2’/3’/4’ structures making up enzyme
Understand the concepts of specificity and the induced fit hypothesis.
lock and key hypothesis = specificity
induced fit = enzyme + substrate distort as they form ES complex
change in enzyme shape puts strain on substrate molecule so destabilising it and reaction occurs more easily
anabolic vs catabolic reaction
anabolic = builds up new molecules
catabolic breaks them down
metabolism
= all anabolic + catabolic processes in a cell
do enzymes catalyse intracellular only
no both intra + extracellular!
factors affecting rate of enzyme activity
temperature, pH, substrate and enzyme concentration
Understand how temperature affect
the rate of enzyme activity.
e+s molecules have more KE energy - more likely to collide + w greater energy so more successful collision sin given time so R increases
BUT at v high T - ROR decreases as increase in vibration energy of atoms weakens non-covalent bonds holding 2; structure of enzymes -> denature -specifc AS shape lost - S will no longer bind - decreases RoR
Understand how pH affect
the rate of enzyme activity.
R decreases either side of optimum pH - due to changes in pH changing ionisation of R groups of AA - alters bonding bw R groups so denatured
Understand how substrate concentration affect
the rate of enzyme activity.
higher = higher rate until con of E is limiting bc all enzymes present as E-S complex so R now is determined by how fast enzyme convert ES -> E+O
Understand how enzyme concentration affect
the rate of enzyme activity.
higher = higher rate as more likely collisions occur until substrate conc limiting
Understand how the initial rate of enzyme activity can be measured and why
this is important.
initial rate = fastest rate - max reaction rate for an enzyme under particular condiitons
draw tangent at start
enzyme inhibitors
slow down enzymes/stop them from working - can see how enzymes work
competitive inhibitors
similar shape to S molecule - compete w binding to AS
non-competitive inhibitor
binds elsewhere to enzyme molecule - changes shape of AS
irreversible inhibitors
- combine w E by permanent covalent bonding - changes shape + structure of molecule
arsenic/cyanide = POISONING
r comp + noncoms inhibitors reversible
YES
end product inhibition, what form of feedback
In end-product inhibition, the final product of a metabolic pathway acts as an inhibitor of an enzyme involved in the first step of that pathway.
This type of inhibition is a form of negative feedback, where the product signals the enzyme to stop producing more product when sufficient amounts are present.
why is end product inhibition good
End-product inhibition is a crucial mechanism for regulating metabolic pathways and ensuring efficient resource allocation within cells.
