Metabolic Pathways Flashcards
what are metabolic pathways?
Metabolic pathways are integrated and controlled pathways of enzyme-catalysed reactions within a cell
what are the 2 types of metabolic pathways?
anabolic and catabolic
describe an anabolic reaction
anabolic reactions build up simple, small molecules into larger more complex ones and does require energy.
describe a catabolic reaction?
catabolic break down large, complex molecules into smaller simpler ones and this reaction releases enrgy.
what can metabolic pathways have?
reversible steps, irreversible steps and alternative routes
what is a chemical reactions activation energy?
the amount of energy required to start a chemical reaction
what are metabolic pathways controlled by?
the absence or presence of particular enzymes and the regulation of the rate of reaction for key enzymes.
what is induced fit?
when the active site of an enzyme changes shape slightly to better fit the substrate that’s binding
how does the enzyme lower activation energy?
the substrates are positioned in a way to get the closest fit as possible which lowers the activation energy
what type of affinity do the products and the substrate have for the active site and what does it mean?
the substrate molecule has a high affinity for the active site meaning it will bind quickly and easily to the active site, where as the products have a low affinity for the active site meaning they can easily leave from the active site
what are the 4 factors that can effect enzyme activity?
pH, temperature, substrate concentration and inhibitors.
why would an enzyme reaction reverse the direction of substrate—-enzyme—-products?
if there was too much product being produced.
how do competitive inhibitors work?
by binding to the active site and therefore blocking the substrate from binding
how can competitive inhibitors be reversed?
by increasing substrate concentration.
how do non-competitive inhibitors work?
by binding away from the active site which causes the enzyme to change shape so the substrate cant bind. this means that increasing substrate concentration does not reverse non-competitive inhibitors.
