Metabolism for survival Flashcards
(41 cards)
What is anabolic pathway
Anabolic: this type of pathway recquires energy and is used to build up large molecules from smaller ones (biosynthesis)
What is catabolic pathway
Catabolic: this type of pathway releases energy and is used to break down large molecules into smaller ones (degradation)
what are metabolic pathways
Metabolic pathways can be described as a series of chemical reactions that start with a substrate and finish with an end product. Metabolic pathways are integrated and controlled enzyme-catalysed reactions within a cell.
What is an example of anabolic reaction
An example of an anabolic reaction is photosynthesis, where plants make glucose molecules from different raw materials.
What is a catabolic pathway
An example of a catabolic reaction is the process of food digestion, where different enzymes break down food particles so they can be absorbed by the small intestine.
What effect does thebinding of the enzyme to its substrate have on the activation energy of the reaction?
It lowers it
What is the active site
The active site of an enzyme refers to the specific region of an enzyme where a substrate binds to and catalyzes a chemical reaction
What is a substrate
A substrate is a molecule that an enzyme reacts with
What do inhibitors do to control metabolic pathways
Inhibitors can be used to stop an enzyme from binding to its substrate.
What is Competitive inhibition
This occurs when an inhibitor molecule binds to the active site of the enzyme and stops the substrate from binding.
What can reverse competitive inhibition
Increasing the substrate concentration
Why does increasing substrate concentration reverse competitive inhibition
This is because the substrate eventually dilutes the inhibitor so that all enzyme molecules bind to the substrate
what is an example of a competitive inhibitor
Sarin
What is non competitive inhibition
This occurs when an inhibitor does not bind to the active site but does bind to a different part of the enzyme and changes the active site shape.
What does non competitive inhibition do
This stops the substrate binding to the enzyme and decreases the reaction rate
Can non competitive inhibition be reversed by increasing the substrate concentration
no
Examples of non-competitive inhibitors
Examples of non-competitive inhibitors include cyanide, mercury and silver.
What can affect the reaction rates in a metabolic pathway
Competitive and non-competitive inhibitors can affect the reaction rates in a metabolic pathway.
What happens to a graph when no inhibitor is present
The graph levels off because all of the active sites are occupied with the substrate.
What happens to a graph when competitive inhibition is present
There is a gradual increase in reaction rate because competitive inhibitors are occupying only some of the enzyme active sites. As substrate concentration increases, the substrate molecules outnumber the inhibitor so the reaction rate reaches the maximum.
What happens to a graph when non competitive inhibition is present
Most enzyme molecules have become inactive but some are unaffected by the inhibitors so reaction rate remains low. An increase in substrate concentration does not increase reaction rate.
What is feedback inhibition
This is when the end product in a metabolic pathway binds to an enzyme at the start of the pathway.
What happens in feedback inhibition
This process stops the metabolic pathway and so prevents further synthesis of the end product until the end product concentration decreases. The higher the concentration of end product, the quicker the metabolic pathway stops.
What is ATP
Adenosine triphosphate is the energy-carrying molecule used in cells
