Exam 1: Chapter 3 Flashcards
What is another name for a drug molecule
a ligand
A ____ is the component of the cell to which endogenous and exogenous compounds bind
receptor
Receptors are usually (lipids/proteins)
proteins
What are the three types of receptors located on the cell’s surface
- Ligand gated (ion channels)
- Linked directly to enzymes
- G proteins (intermediate regulatory)
What type of receptor is acetycholine
ligand gated/ion channel
When activated, an acetylcholine receptor opens a ____ ion channel
Na+
True or False:
receptors that are linked directly to enzymes are channels
false
Give an example of a receptor that is link directly to an enzyme
Insulin attaches to a binding domain and activates the inner portion/catalytic domain
Which type of receptor alters an intracellular effector a distance away from the receptor
G-proteins, linked to an intermediate regulatory
What is another name for a G protein
a second messenger
Is acetylcholine endogenous or exogenous
endogenous
A second drug that can bind to a receptor protein and cause the same effect as the first drug is called an ____
agonist
A second drug that can bind to a receptor and blocks an effect of the first drug is called a _____
antagonist or blocker
What is a common example of a second message
cyclic AMP
Explain the mechanism of a second messenger interaction
A free peptide in the bloodstream attaches to a fixed membrane receptor on a target cell. The peptide releases a second messenger (cyclic AMP). The second messenger activates a series of enzymes reactions that alter cell function until the intended function occurs
Where are intracellular receptors located
in the cytoplasm and within the nucleus
What drug often binds with intracellular receptors via passive diffusion
steroids
Steroids enter the cell by passive diffusion and bind with receptors in the (nucleus/cytoplasm)
cytoplasm
Hormones like thyroxin enter the cell by passive diffusion and bind with receptors in the (nucleus/cytoplasm)
nucleus
Intracellular receptors bind to _____ and cause change in ____ expression and mRNA transcription
genes, gene
True or False:
Altered protein synthesis results in altered cell function
true
A drug-receptor relationship is like a ___ - ___ relationship
key-lock
The ability of a drug to interact with the receptor depends upon what three things
- size of drug
- shape of drug
- configuration of the binding site on the receptor
- The flexibility/fluidity of the cell membrane
What is affinity
the attraction of a drug to a receptor
What term is described as the attraction of a drug to a receptor
affinity
Drugs with a low to moderate affinity require a (low/high) concentration to load the receptor
high
The flexibility/fluidity of the cell membrane can effect the drug binding to the receptor which is effected by the _____ and ____ of the patient
health and nutrition
What are the five types of functional proteins in the cell membrane
- Channels
- Transporters
- Enzymes
- Receptors
- Structural proteins
What are the four types of receptors
- Ligand gated
- Enzyme liked
- G protein
- Intracellular receptors
True or False:
hydrophilic molecules can easily pass through the cell membrane
False, they cannot so they requires a ligand-gated channel
Explain how a ligand-gated channel works
A ligand binds to a receptor on the outside of the channel, the receptor opens the channel and allows Na+ to flow into the cell and K+ flows out of the cell
Explain how enzyme linked receptors work
A ligand binds to a receptor outside of the cell which activates enzymes inside of the cell. ATP/GTP inside of the cell transforms into cAMP
Explain how G-protein receptors work
A ligand binds to a receptor outside of the cell membrane which changes the shape of the receptor, which then changes the shape of the G protein. This activates enzymes and effector proteins
Explain how intracellular receptors work
Ligands that can pass through the membrane enter the cell and either bind to receptors in the nucleus or cytoplasm. This can alter transcription of DNA within a cell
What is the result of a drug-receptor interaction
a change in cell function or the blocking of cell function
an agonist has (affinity/efficacy)
affinity and efficacy
____ is when a drug is attracted and binds to a receptor
affinity
____ is when a drug binds to the receptor and causes a change in cell function
efficacy
An antagonist has (affinity/efficacy)
affinity but no efficacy
What is a competitive antagonist
inhibitory drugs that are trying to reach the same receptor before an agonist gets to that same receptor
True or False:
A competitive antagonist molecule with greater concentration will win the receptor spot
true
If a competitive antagonist (which is inhibitory) is causes an adverse effect, how is the competitive antagonist overcome
Increasing the concentration of an agonist to overpower the antagonist
What is a noncompetitive antagonist
Antagonists that try to reach the same receptor as an agonist, but once the antagonist is binded with a receptor, it cannot be overpowered no matter how strong the concentration of the agonist
What is a partial agonist
an agonist that occupies the receptor site but has a decreased efficacy because it doesn’t release a full effect of that drug or whatever the agonist is
Partial agonists have a (poor/strong) affinity but a (poor/strong) efficacy
strong, poor
What type of medications can function as partial agonists that provide adequate effects without unwanted side effects
anti-anxiety
In general, prolonged stimulation of receptors will lead to a/an (decrease/increase) in receptor function which is called ________ or a decrease in receptor population which is called _____-______
decrease; desensitization; down-regulation
In general, decreased stimulation of a receptor will result in a/an (decrease/increase) in receptor sensitivity or an increase in number of receptors called __-_______
increased; up regulation
A drug is said to be _____ if it affects one type of cell or tissue
selective
What is the selectivity of a drug
A function of a drugs ability to interact with receptors located on cells/tissues
The (less/more) selective the drug the fewer the different side effects
more
True or False:
When a selective drug is designed, it is superior to less selective drugs in the same category
true
A less selective drug attaches to a similar yet different receptor that can cause unwanted (pharmacokinetics/pharmacodynamics)
pharmacodynamics
