1.6. Metabolic Pathways Flashcards
What does catabolic mean?
The metabolic pathway brings about the breakdown of complex molecules to simpler ones. Usually this releases energy.
What does anabolic mean?
The metabolic pathway brings about the biosynthesis of complex molecules from simpler ones. Usually this requires energy.
What is each step in a metabolic pathway controlled by?
A specific enzyme.
How do enzymes speed up reactions?
By lowering the activation energy.
What is activation energy?
The energy required for a reaction to start.
What is the active site?
The place on the enzyme that the substrate binds to.
What is induced fit?
When the active site changes shape to help the substrate bind to it more easily.
What is an inhibitor?
A chemical that slows down or stops a reaction controlled by enzymes.
What is competitive inhibition?
It involved inhibitors which have a similar shape to the normal substrates. It is because of this similar shape that they block the active site. Increased concentration of the substrate lowers the chances of competitive inhibition occurring.
What is non-competitive inhibition?
When an inhibitor binds to the enzyme not at the active site, altering the active sites shape, stopping the substrate from binding. This is not affected by substrate concentration.
What is feedback inhibition?
When an end product inhibits the activity of an enzyme that catalysed a reaction earlier on in the pathway that produced it.
How do metabolic pathways avoid resources being wasted?
By turning genes that code for enzymes of specific steps on and off as required.
