Deck 23: Chemical Communications: Neurotransmitters and Hormones

Question 1

Which of the following organelles are found within a cell?

A) nuclei
B) mitochondria
C) both nuclei and mitochondria
D) neither nuclei nor mitochondria

Answer 1

C

Question 2

Which of the following biological molecules used for cellular communication carry messages from the receptor to the inside of the cell?

A) primary messengers
B) secondary messengers
C) both primary messengers and secondary messengers
D) neither primary messengers nor secondary messengers

Answer 2

C

Question 3

Which of the following are the hair-like part of a nerve cell?

A) axons
B) dendrites
C) synapses
D) vesicles

Answer 3

B

Question 4

Which of the following is a long fiber-like part of a nerve cell?

A) an axon
B) a dendrite
C) a synapse
D) a vesicle

Question 5

Identify an example of a neural transmission in animals.

A) regulation of the blood sugar level in the body
B) contraction of blood vessels in response to the secretion of vasopressin by the posterior pituitary gland
C) communication between the eyes and the brain
D) binding of adrenaline to specific receptors in liver cells

Question 6

Which of the following drugs blocks the receptor and prevents its stimulation?

A) an agonist drug
B) an antagonist drug
C) both of these
D) none of these

Question 7

Which of the following inhibitors of acetylcholinesterase was used in poisoned arrows by the Amazon Indians?

A) curare
B) nicotine
C) succinylcholine
D) none of these

Question 8

Which of the following biological molecules used for cellular communication is also called the ligand?

A) a chemical messenger
B) a secondary messenger
C) a receptor
D) none of these

Question 9

Which of the following cells communicate with each other through neurotransmitters?

A) muscle cells
B) cells of a gland
C) neurons
D) all of these

Question 10

What is the aqueous small space between the axon end of one neuron and the cell body of the next neuron called?

A) an axon
B) a dendrite
C) a synapse
D) a vesicle

Question 11

Where are neurotransmitters stored in a nerve cell?

A) in the axon
B) in dendrites
C) in the synapse
D) in vesicles

Question 12

Which of the following is a function of a secondary messenger?

A) It assists in the induction of a physiological response in a cell or a tissue.
B) It carries a message from the receptor to the inside of a cell.
C) Both of these are the functions of a secondary messenger.
D) Neither of these are functions of a secondary messenger.

Question 13

Which of the following is the function of a secondary messenger?

A) It assists in the amplification of a biological message.
B) It carries a message from the receptor to the inside of a cell.
C) Both of these are functions of the secondary messenger.
D) Neither of these are functions of the secondary messenger.

Question 14

How are neurotransmitters and hormones distinct from each other?

A) by their chemical nature
B) by their physiological behavior
C) both of these
D) none of these

Question 15

Which of the following drugs competes with the natural messenger for the receptor site?

A) an agonist drug
B) an antagonist drug
C) both of these
D) none of these

Question 16

Which of the following compounds acts as a stimulant of acetylcholine receptors when given in low doses?

A) donepezil
B) nicotine
C) opiate
D) none of these

Question 17

Which of the following drugs blocks the receptor sites of enkephalins?

A) curare
B) morphine
C) opiate
D) none of these

Question 18

Which of the following drugs activates the receptor sites of enkephalins?

A) curare
B) opiate
C) nicotine
D) none of these

Question 19

Where are receptors found in an animal cell?

A) They are found on the surface of cells.
B) They are found freely roaming in the cytosol.
C) They are found on the surface of mitochondria.
D) All of these are correct.

Question 20

Which of the following statements is true of a hormone?

A) It acts over a short distance across a synapse.
B) It acts over a long distance from the secretory gland through the bloodstream to the target cell.
C) It acts over a short distance across a synapse and it acts over a long distance from the secretory gland through the bloodstream to the target cell, depending on the chemical properties of the hormone.
D) None of these

Question 21

Which of the following compounds is a secondary messenger?

A) cAMP
B) G-protein
C) vasopressin
D) GTP

Question 22

Which of the following classes of chemical messengers include hormones?

A) adrenergic
B) peptidergic
C) steroid
D) all of these

Question 23

Which of the following ions can pass through the open ion channel of the acetylcholine receptor?

A) Ca²⁺
B) K⁺
C) both Ca²⁺and K⁺
D) neither Ca²⁺ nor K⁺

Question 24

Which of the following statements is true of succinylcholine?

A) It acts as a muscle relaxant when given in small doses.
B) It strains muscles when given in small doses.
C) It is an irreversible inhibitor of acetylcholine.
D) None of these are true.

Question 25

Which of the following hormones acts through a secondary messenger?

A) epinephrine
B) glucagon
C) luteinizing hormone
D) all of these

Question 26

Which of the following ions is associated with acetylcholine as a secondary messenger?

A) Ca²⁺
B) Cl⁻
C) Mg²⁺
D) H⁺

Question 27

Which of the following proteins is associated with the receptor site of norepinephrine?

A) G-protein
B) K-protein
C) F-protein
D) P-protein

Question 28

Which of the following is not a class of chemical messengers?

A) cholinergic
B) amino acid
C) adrenergic
D) carboxylic acid

Question 29

Which of the following statements is true of epinephrine?

A) It is a hormone but not a neurotransmitter.
B) It is a neurotransmitter but not a hormone.
C) It is both a hormone and a neurotransmitter.
D) It is neither a hormone nor a neurotransmitter.

Question 30

Which of the following hormones can cross the plasma membrane by passive diffusion?

A) progesterone
B) glucagon
C) insulin
D) epinephrine

Question 31

Identify a function of the enzyme acetylcholinesterase.

A) synthesis of acetylcholine
B) hydrolysis of acetylcholine
C) esterification of acetylcholine
D) polymerization of acetylcholine

Question 32

How many different subunits are present in an acetylcholine transmembrane receptor?

A) four
B) five
C) six
D) seven

Question 33

Which of the following hormones is produced by the posterior lobe of the pituitary gland?

A) prolactin
B) epinephrine
C) renin
D) vasopressin

Question 34

Which of the following classes of chemical messengers do not include hormones?

A) adrenergic
B) cholinergic
C) peptidergic
D) steroid

Question 35

Which of the following hormones is produced in the kidneys?

A) insulin
B) glucagon
C) renin
D) vasopressin

Question 36

Identify a correct statement about cholinergic receptors.

A) They are peripheral proteins.
B) They are made of six different subunits.
C) They act as ion channels for Na⁺ and K⁺ ions.
D) They bind to norepinephrine.

Question 37

Identify a protein that binds with Ca²⁺ ions in smooth muscles and initiates signal transduction.

A) acetylcholine
B) calmodulin
C) epinephrine
D) norepinephrine

Question 38

Which of the following neurotransmitters or hormones is classified as adrenergic messengers?

A) acetylcholine
B) epinephrine
C) estradiol
D) none of these

Question 39

Which of the following ions can pass through the open ion channel of the acetylcholine receptor?

A) K⁺
B) Na⁺
C) both K⁺ and Na⁺
D) neither K⁺ nor Na⁺

Question 40

Which of the following hormones is not produced in the pancreas?

A) insulin
B) glucagon
C) renin
D) none of these

Question 41

How are glutamic acid molecules removed from its receptor site?

A) by degrading the receptor site
B) by transporter molecules
C) by the process called uptake
D) by degrading glutamic acid

Question 42

Which of the following is an inhibitory neurotransmitter?

A) aspartic acid
B) cysteine
C) taurine
D) none of these

Question 43

Which of the following neurotransmitters is an adrenergic messenger?

A) dopamine
B) histamine
C) serotonin
D) all of these

Question 44

Which of the following neurotransmitters is an adrenergic messenger?

A) acetylcholine
B) dopamine
C) taurine
D) all of these

Question 45

Which of the following is an effect of cobratoxin?

A) It increases the synthesis of acetylcholine.
B) It binds irreversibly with the enzyme acetylcholinesterase.
C) It binds reversibly with the enzyme acetylcholinesterase.
D) It prevents the communication between neurons and muscle cells.

Question 46

Which of the following is associated with signal transduction?

A) the amplification of a signal
B) the cessation of a signal
C) the modulation of a signal
D) none of these

Question 47

Which of the following is not a pathological hallmark for the postmortem identification of Alzheimer's disease?

A) the buildup of β-amyloid plaques
B) neurofibrillar tangles composed of tau proteins
C) brain shrinkage
D) brain enlargement

Question 48

Which of the following compounds is an antagonist of the N-methyl-D-aspartate (NMDA) receptor?

A) γ-aminobutyric acid
B) phencyclidine
C) taurine
D) none of these

Question 49

How much time does it takes for cAMP molecules to amplify a biochemical signal?

A) 1-10 milliseconds
B) 10-100 milliseconds
C) 0.1 s to a few minutes
D) more than 5 minutes

Question 50

Which of the following reactions causes the detachment of tau proteins from the microtubules?

A) hydrolysis
B) condensation
C) dissociation
D) phosphorylation

Question 51

Which of the following is not a result of signal transduction?

A) protein modifications
B) enzyme activation
C) opening of membrane channels
D) all of these

Question 52

Which of the following ions closes the ligand-gated ion channel of NMDA?

A) K⁺
B) Na⁺
C) Mg⁺²
D) Ca⁺²

Question 53

To which class of compounds do adrenergic messengers belong?

A) amides
B) monoamines
C) amino acids
D) steroids

Question 54

Which of the following statements is true of nicotine?

A) It acts as an agonist at all doses.
B) It acts as an antagonist at all doses.
C) It acts as an agonist at low doses but as an antagonist at high doses.
D) It acts as an agonist at high doses but as an antagonist at low doses.

Question 55

Which of the following is an excitatory neurotransmitter?

A) β-alanine
B) cysteine
C) taurine
D) none of these

Question 56

Which of the following amino acids binds to the N-methyl-D-aspartate (NMDA) receptor?

A) aspartic acid
B) asparagine
C) glutamic acid
D) glutamine

Question 57

Which of the following statements is true of the receptor site of amino acid neurotransmitters?

A) All amino acids have a common receptor site.
B) Each amino acid has its own receptor site.
C) Each amino acid has only one receptor site.
D) None of the these statements are true.

Question 58

Which of the following compounds is a substrate of adenylate cyclase?

A) APP
B) ADP
C) AMP
D) ATP

Question 59

Which of the following compounds is produced by the phosphodiesterase-catalyzed hydrolysis of cAMP?

A) APP
B) ADP
C) AMP
D) ATP

Question 60

Which of the following is a natural alkaloid that acts as a potent inhibitor of acetylcholinesterase?

A) donepezil
B) rivastigmine
C) galantamine
D) huperzine A

Question 61

Identify the reaction that is involved in the inactivation of monoamines by converting them to aldehydes.

A) condensation
B) hydrolysis
C) oxidation
D) reduction

Question 62

Which of the following drugs is the first dedicated antidepressant that was initially used to treat tuberculosis?

A) Prozac
B) Lexapro
C) Ketamine
D) Isoniazid
E) Xanax

Question 63

Which of the following diseases is associated with an insufficient production of dopamine?

A) Alzheimer's disease
B) Cholera
C) Parkinson's disease
D) Diphtheria

Question 64

What is a function of the brain peptide called neuropeptide Y?

A) It stimulates appetite.
B) It suppresses appetite.
C) It suppresses pain.
D) It transmits pain signals.

Question 65

Which of the following statements is true of peptidergic messengers?

A) They primarily belong to the group of hormones that affect metabolism.
B) They do not utilize G-protein-adenylate cyclase as a secondary messenger system.
C) They include neuropeptides that act as potent anorexic agents.
D) None of these are true.

Question 66

Which of the following is a function of phosphatidylinositol diphosphate?

A) It stimulates the release of calcium ions from sarcoplasmic reticulum.
B) It stimulates the dephosphorylation of enzymes.
C) It enhances the synthesis of G-proteins.
D) It enhances the storage of calcium ions in sarcoplasmic reticulum.

Question 67

Which of the following drugs is used to block H₁ receptors of histamine?

A) cimetidine
B) diphenhydramine
C) ranitidine
D) galantamine

Question 68

How does cyclic AMP activate a protein kinase?

A) by phosphorylating the regulatory unit
B) by dissociating the catalytic unit from the regulatory unit
C) by phosphorylating the catalytic unit
D) by phosphorylating the ion-translocating protein

Question 69

Identify a peptide that binds to specific pain receptors and controls pain perception.

A) enkephalin
B) neuropeptide Y
C) leptin
D) substance P

Question 70

Which of the following statements is true of the G-protein-adenylate cyclase cascade?

A) It is only associated with monoamine messengers.
B) It is only associated with peptidergic messengers.
C) It is associated with both monoamine and peptidergic messengers.
D) It is associated with neither monoamine nor peptidergic messengers.

Question 71

What happens to the steroid-receptor complex inside the nucleus?

A) It binds directly to the DNA.
B) It binds with a translation factor.
C) It gets dissociated into separate components.
D) It creates an ion channel into the nucleoplasm.

Question 72

Which of the following diseases is associated with the overproduction of cAMP by activated G-proteins?

A) Alzheimer's disease
B) Cholera
C) Parkinson's disease
D) Diphtheria

Question 73

What is the function of antidepressants such as Marplan?

A) It increases the activity of monoamine oxidases.
B) It suppresses the activity of monoamine oxidases.
C) It enhances the G-protein−adenylate cyclase cascade.
D) It suppress the synthesis of monoamine messengers.

Question 74

What is a function of the peptidergic neurotransmitter called substance P?

A) It stimulates appetite.
B) It suppresses appetite.
C) It suppresses pain.
D) It transmits pain signals.

Question 75

Which of the following statements is true of the receptors of steroid hormones?

A) They are hydrophilic in nature.
B) They are protein receptors.
C) Both of these statements are true.
D) Neither of these statements is true.

Question 76

What is the physiological role of a steroid hormone?

A) to activate enzymes
B) to regulate gene expression
C) to manipulate membrane permeability
D) all of these

Question 77

Which chemical form of phosphatidylinositol acts as a signaling molecule?

A) the phosphorylated form
B) the carboxylated form
C) the reduced form
D) the oxidized form

Question 78

Which portion of an enkephalin is assumed to fit the receptor site?

A) the C-terminal portion
B) the entire molecule
C) the central portion
D) the N-terminal portion

Question 79

Which of the following molecules is a byproduct of the conversion of histidine into histamine?

A) CO₂
B) HCl
C) H₂O
D) NO

Question 80

Identify the enzyme that is involved in the conversion of monoamines into aldehydes.

A) peroxidase
B) succinyl dehydrogenase
C) monoamine oxidase
D) phosphodiesterase