pharmacodynamics study guide Flashcards
(87 cards)
T or F: drugs alter the physiological processes already present in the body, but they do not produce new effects.
True
How do drugs produce their effects?
Through cellular or extracellular actions, mimicking or blocking endogenous chemicals.
What is a drug target?
A site that can be functionally altered by interaction (binding) with a drug molecule.
What is a physiological receptor?
Specialized protein that receives a chemical signal, leading to a cellular change in function. Receptors are a subset of drug targets, and most drugs work by altering receptor activity.
Four Basic Types of Receptors
Intracellular Receptors
Ligand-gated ion channels
Enzyme-linked Receptors
G-protein coupled Receptors
Cellular Targets that are NOT physiological receptor proteins
o Voltage –gated ion channels
o DNA
o Structural proteins
o Intracellular enzymes
o Transporter proteins
How do drugs interact with intracellular receptors?
Drugs must be able to cross the cell membrane to interact with intracellular receptors.
What happens when a drug interacts with an intracellular receptor?
The drug alters the reading of DNA, which results in altered protein levels and changes in cellular function.
Where are intracellular receptors found?
inside the cell
What happens when a ligand binds to a ligand-gated ion channel?
The binding of the ligand opens the ion channel.
Where are ligand-gated ion channels found?
in the cell membrane and are typically made up of multiple proteins
What is the result of ion movement through ligand-gated ion channels?
Specific charged particles (ions) move into or out of the cell, leading to changes in cell function.
Where are enzyme-linked receptors found?
in the cell membrane, with the ligand binding on the outside and the enzyme on the inside.
What happens when an enzyme-linked receptor is activated?
activates the enzyme inside the membrane.
What biological processes are enzyme-linked receptors often associated with?
cell growth and multiplication, such as in the immune system.
Where are G-protein coupled receptors found?
large proteins found in the cell membrane, with the ligand binding site on the outside and the G-protein binding site on the inside.
What is binding affinity?
the strength of the bond between a drug and its receptor, and it is related to the drug’s potency (how much is needed to produce a certain effect).
What happens when a G-protein coupled receptor is activated by a ligand,?
the G-protein breaks off and interacts with different structures in the cell, causing a change in cellular function
Are drug-receptor interactions reversible?
Yes
How does a drug bind to a receptor?
structurally specific manner, similar to a lock-and-key mechanism.
What is efficacy?
drug’s ability to activate a receptor and produce the maximum possible effect it can generate.
What is an agonist?
drug that increases receptor activity
What is a direct agonist?
binds directly to the receptor and activates it
Where does a direct agonist bind?
endogenous ligand site