Metabolism Flashcards
What is a Signal Transduction Pathway
Interaction between Receptor Proteins in Plasma Membrane and Proteins/Aminoacids
How do Proteins act once they interact with the intended molecule
Activation of Proteins (Secondary messengers) inside the cell
Example of G-coupled Pathway hormones
Glucagon , adrenalin and PTH
What happens when a Gs protein is activated
Stimulation of Adenyl Cyclase which increases cAMP and activates PKA = Transcription Factor
What is Metabolism
All biochemical reactions occuring in the organism
Main functions of Metabolic Pathways
- Formation of ATP
- Creation of structural biomolecules
- Elimination of waste molecules
What is a biochemical pathway
Sequence of reactions required to convert one REACTANT molecule to a PRODUCT
What are the 2 main mechanism of Regulation in biochemical pathways
- Allosteric inhibition
- Feedback Inhibition
What is Allosteric Inhibition
Biomolecule which interact with enzyme (at a different site) and either Activates or Deactivates it
What is feedback inhibition
The PRODUCT of an enzyme inhibits enzyme’s function
What is an enzyme
Protein which catalyze or facilitate biochemical reactions
Molecule that can be used to switch on or off a metabolic pathway
Enzyme
What are enzyme kinetics
How Enzyme catalyzed reactions are affected by various conditions (eg: Inhibitors)
The Rate of Reaction (Vo) depends on
- Concentration of Reactant/Substrate [S)
- Max reaction rate of an enzyme (Vmax)
- Michaelis constant of the enzyme (KM)
Michaelis-Menten equation is used to
Calculate the rate of reaction
Michaelis-Menten equation is
Vo= [ (Vmax) x [S] ] / [KM + [S] ]
What is a Linewaver-Burk Plot
Representation of the inverse of Michaelis-Menten equation
Linewaver-Burk Plot is used to
- Calculate KM and Vmax of enzymes
- Identify the presence of Activators or Inhibitors
The point in Linewaver-Burk Plot where the Y axis is crossed represents
1/ Vmax
The point in Linewaver-Burk Plot where the X axis is crossed represents
1/ KM
The X and Y axis in Linewaver-Burk Plot represents
X = [S]
Y = [Vmax]
Michaelis Constant property
The velocity reaction is half the Vmax when MK and [S] are numerically equal
How does a Competitive inhibitor affects Linewaver-Burk Plot
1/KM = Changes (Increases)
1/Vmax = Same
How does a Uncompetitive inhibitor affects Linewaver-Burk Plot
1/KM = Decreases
1/Vmax = Decreases
Less KM means
More affinity
Competitive inhibitor can be reversed by
Increasing substrate [S]
Why does KM decreases in Uncompetitive inhibitor
Increases affinity for the Substrate. But Inhibits complex Enzyme-Substrate.
Cannot go back and cannot form product
How does a Non-Competitive inhibitor affects Linewaver-Burk Plot
KM = Same
Vmax = Decreases
The only inhibition that can be reversed by increasing substrate is
Competitive inhibitor.
