Fundamentals of Pharmacology Agonists Quiz

<p>Receptors show structural and steric specificity. (C)</p> Signup and view all the answers

<p>The receptor has a limited number of binding sites. (D)</p> Signup and view all the answers

<p>A biochemical event occurs within the cell. (B)</p> Signup and view all the answers

<p>The size, shape, and charge of the binding pocket. (D)</p> Signup and view all the answers

<p>Drugs must bind to a receptor or other target to cause an effect (B)</p> Signup and view all the answers

<p>They exhibit a high degree of specificity, where a particular ligand binds to a specific receptor. (A)</p> Signup and view all the answers

<p>To primarily act as binding sites for hormones and neurotransmitters. (C)</p> Signup and view all the answers

<p>A key fitting into a lock, where the key (ligand) is specific to its appropriate lock (receptor). (C)</p> Signup and view all the answers

<p>Intracellular receptor (steroid-ER) (B)</p> Signup and view all the answers

<p>They activate G proteins and initiate downstream signalling cascades. (C)</p> Signup and view all the answers

<p>Receptors are unique to specific cells and tissues. (D)</p> Signup and view all the answers

<p>It binds to a receptor and produces a physiological response. (A)</p> Signup and view all the answers

<p>The size of the response varies with the proportion of occupied receptors. (A)</p> Signup and view all the answers

<p>Emax (A)</p> Signup and view all the answers

<p>EC50 (C)</p> Signup and view all the answers

<p>The amount of drug required to produce an effect of given intensity (C)</p> Signup and view all the answers

<p>Lower EC50 and the same Emax (B)</p> Signup and view all the answers

<p>Kd (A)</p> Signup and view all the answers

<p>The maximum number of receptors bound by the drug (B)</p> Signup and view all the answers

<p>Both the drug concentration and the dissociation constant (C)</p> Signup and view all the answers

<p>Receptor binding is reversible (C)</p> Signup and view all the answers

<p>It depletes downstream mediators. (D)</p> Signup and view all the answers

<p>After frequent or continuous exposure to an agonist. (B)</p> Signup and view all the answers

<p>EC50 is less than Kd. (C)</p> Signup and view all the answers

<p>It promotes receptor internalization. (C)</p> Signup and view all the answers

<p>Increased sensitivity to the agonist. (C)</p> Signup and view all the answers

<p>It binds to the receptor but produces a smaller maximal effect. (A)</p> Signup and view all the answers

<p>The drug's ability to produce a response upon receptor activation. (A)</p> Signup and view all the answers

<p>An agonist brings about a reaction while an antagonist does not. (C)</p> Signup and view all the answers

<p>The concentration at which 50% of the maximum effect is observed. (C)</p> Signup and view all the answers

<p>Drug A binds more effectively to receptors than Drug B. (A)</p> Signup and view all the answers

<p>They can display both agonistic and antagonistic effects. (B)</p> Signup and view all the answers

<p>It acts as an antagonist, reducing activity. (B)</p> Signup and view all the answers

<p>Aripiprazole (A)</p> Signup and view all the answers

<p>They help increase the sensitivity to agonists. (A)</p> Signup and view all the answers

<p>It is an opioid partial agonist with significant analgesic effects. (B)</p> Signup and view all the answers

<p>The drugs' EC50 and Kd values. (B)</p> Signup and view all the answers

<p>Partial agonists produce a smaller effect than full agonists. (D)</p> Signup and view all the answers

<p>The concentration at which 50% of receptors are bound. (B)</p> Signup and view all the answers

A molecule that a drug binds to, causing a change in the function of the biological system.

A chemical that specifically binds to a receptor.

A ligand that binds to a receptor and causes a biological response.

A ligand that binds to a receptor but doesn't cause a response, and can block other ligands.

The ability of a receptor to bind to specific ligands due to its shape and chemical properties.

The amount of a drug needed to produce a specific effect.

The concentration of a ligand needed to occupy half of the available receptors.

The maximum number of binding sites on a receptor.

The concentration of a ligand that produces 50% of the maximal response.

The concentration of a ligand that occupies 50% of the receptors.

The maximum number of binding sites for a ligand on a receptor.

The ability of a ligand to produce a maximal response when bound to a receptor.

A drug that binds to a receptor and causes a biological response.

A state where a receptor's ability to respond to an agonist is reduced after repeated or continuous exposure to the agonist.

The process by which receptors are internalized into the cell after being activated, effectively reducing their availability for further signaling.

Receptors that exist in excess of the number needed to produce a maximal effect. These spare receptors contribute to the sensitivity of the system to agonists.

When spare receptors are present, the concentration of an agonist required to produce half the maximum effect (EC50) is lower than the ligand concentration required to occupy half the receptors (Kd).

A receptor shows high selectivity for its ligand. This means that only specific molecules can bind and activate the receptor. For example, adrenaline binds to β1-adrenoreceptors to increase heart rate and force of contraction.

Receptors play vital roles in normal body functions. They act as targets for hormones, neurotransmitters, and other signaling molecules to regulate various bodily processes.

Drugs are designed to interact with specific receptors to achieve therapeutic effects. This selectivity allows drugs to target specific tissues and minimize side effects.

Ligand-receptor interactions are based on complementary shapes and forces, similar to enzyme-substrate interactions. The ligand fits into a specific binding site on the receptor, like a key fits into a lock.

Intracellular receptors are located inside the cell and are activated by steroid hormones. These receptors can then regulate gene expression.

Transmembrane receptors with intrinsic tyrosine kinase activity are located in the cell membrane. They have tyrosine kinase activity that is activated upon ligand binding, leading to downstream signaling pathways.

Transmembrane receptors that activate separate tyrosine kinase enzymes are also located in the cell membrane. These receptors bind ligands and activate a separate tyrosine kinase enzyme, leading to downstream signaling.

Ligand-gated ion channels are transmembrane proteins that open or close in response to ligand binding. This allows ions to flow through the membrane, altering electrical activity.

The concentration of a drug needed to produce 50% of its maximum effect. It reflects how potent a drug is - how much is needed to get a response.

The ability of a drug to bind to its receptor. It determines how strongly a drug interacts with its target.

Studies that directly measure the binding of a radiolabelled drug to a tissue. They give information about affinity and receptor number.

A type of study that assesses the functional response of a drug, not just its binding. It determines the actual effect of the drug.

The law of mass action is a principle that explains how the binding of a drug to a receptor is influenced by their concentration and affinity.

A drug that binds to a receptor and produces a weaker effect (lower Emax) compared to a full agonist, even at high concentrations.

They can act as antagonists by competing with full agonists for the same receptor, reducing the full agonist's effectiveness.

Aripiprazole (Abilify) is a partial agonist used to treat schizophrenia by balancing dopamine activity, acting as an agonist in areas with low dopamine and an antagonist in areas with high dopamine.

Buprenorphine (Suboxone) is an opioid partial agonist that provides pain relief while having a lower risk of respiratory depression compared to full opioid agonists like morphine.

The maximum effect a drug can achieve, represented as Emax on a dose-response curve.

The concentration of a drug required to produce 50% of its maximum effect, represented as EC50 on a dose-response curve.

A partial agonist binds to its receptor but produces a smaller effect (lower Emax) at full dosage compared to a full agonist due to its intrinsic activity.