Metabolic Pathways Flashcards
Metabolism
All the chemical reactions that occur within the human body
What do metabolic pathways involve
The building up and breaking down of molecules (substrates)
Anabolic pathways
Require energy and involve biosynthetic processes (building up) e.g. joining of amino acids
Catabolic pathways
Release energy and involves the breaking down of molecules e.g. breakdown of glucose in respiration
The rate of chemical reaction is indicated by
The quantity of chemical change that occurs per unit time
Enzymes contain an active site which
Is a specific shape due to the structure and bonding of the amino acids
An enzyme only acts on one substrate because
Molecules of substrate are complimentary to the shape of the active site for which they show an affinity
Products of a reaction have a
Low affinity for the active site and are released, leaving the enzyme free to repeat the process
The active site of an enzyme
Is a flexible and dynamic structure
Induced fit
When the shape of the active site changes slightly to fit the substrate better
When the reaction involves two or more substrates, what does the shape of the active site determine?
the orientation of the reactants
What does an enzyme require to function efficiently
- Suitable temperature
- Suitable pH
- Sufficient enzyme/substrate concentration
What do inhibitors do
Slow down (or stop) the rate of an enzyme controlled reaction
As substrate concentration increases
Rate of reaction increases and then the rate remains constant as all active sites are occupied
What can metabolic pathways be controlled by
Presence or absence of an enzyme, as key enzymes regulate the rate of reaction within a pathway
