3.4 Pharmaceuticals Flashcards
Unit 3: Organic Chemistry
What is a drug?
A substance that alters a biochemical process in the body
What types of drugs are used as medicines?
Any that have a beneficial effect
What does a medicine contain?
The drug (active ingredient) and other ingredients that allow them to be taken easily
How do drugs exert their effect in cells?
-Most interact with a specific target protein molecule on the cell surface (receptor) or inside the cell (often an enzyme)
-If they acid inside a cell there must be a mechanism to cross the cell membrane, could be passive diffusion or a transport mechanism (a membrane protein)
How does a Transporter allow drugs to enter the cells?
-Act as a pore or channel
-Bind to the drug molecule and then change shape to move it across the membrane
How does a Receptor allow drugs to enter the cells?
-They bind to a specific compound
-The receptor transduce the binding signal into a response inside the cell, allowing a specific reaction pathway to take place
What are Protein molecules?
Complex macromolecules made from long unbranced chain of amino acids
What is the critiera required for a protein to allow a drug to fit?
-The shape of the drug fits the binding site of the receptor or the active site of the enzyme
-The shape of the drug and receptor must be complementary
-The electrostatic, hydrophobic and hydrogen bonding surfaces of the drug molecule and the receptor are complementary allowing vander wall forces and or ionic bonding to take place
How does an Agonist drug work?
(Drug mimic) - (mimics the active compound)
These bond to the receptor and trigger a similar effect to the molecule that would naturally bind to the receptor - this stimulates a similar response to the natural compound
How does an Antagonist drug work?
(Blockers/Inhibitors)
These bind to the receptor molecules but are not close enough in structure to cause the change in the receptor that the natural compound would. This blocks the active site so prevents that natural compound from binding, therefore blocking the natural response from occuring
How does an enzyme interact with its substrate?
-They have an active site into which the substance binds
-The shape and properties of the active site are complementary to those of the substance
-Once bound the enzyme induces a change
-Stresses the bonds, reducing activation energy
- Given the substrate better geometry
These make the reaction more likely to occur
How does an enzyme inhibitor have an effect?
They bind to the enzyme affecting its ability to catalyses a reaction. Competitive inhibitors bind to the active site preventing the substance from binding, this blocks the enzyme from catalusing a specific reaction in a metabolic pathway so the pathway cant proceed
What is a pharmcophore?
A structural fragment that interacts with the binding site of a receptor or enzyme
How does the structure of morphine allow it to act as a drug for pain relief?
They have a common fragment in their structure (the pharacophore). The morphine pharacophore is similar enough in structure that is can bind to the endorphin receptor in the cell membrane, acting as an agonist causing a similar effect in the cell as the natural compound - pain relief
What does identifying the pharocophore allow scientists to do?
Create drugs with fewer side effects or develop new drugs
