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51 QuestionsShow answers
Question 1
SURVEY
30 seconds
Q. The three stages of cell signalling are
answer choices
paracrine, local, and synaptic
reception, transduction, and response
transcription, translation, and folding
alpha, beta, and gamma
Question 2
SURVEY
30 seconds
Q. Each of the following numbered processes are involved in signal transduction pathways: I. Response II. Amplification III. Reception IV. Transduction Which of the following represents the sequence of events in a typical signal transduction pathway?
answer choices
I, II, III, IV
III, I, IV, II
II, IV, I, III
III, IV, II, I
Question 3
SURVEY
30 seconds
Q. G proteins are a family of proteins involved in transmitting chemical signals originating from outside a cell into the inside of the cell. G proteins function as molecular switches. Which of the following best describes the role in which the G protein is most intimately involved in the process shown above?
answer choices
Production of the ligand molecule.
Reception of the signal.
Transduction of the signal.
Production of response to signal.
Question 4
SURVEY
30 seconds
Q. All of the following statements about ligand-receptor complexes are true EXCEPT
answer choices
A. Most receptors exhibit ligand specificity.
Ligand–receptor interactions are reversible
Ligand–receptor interactions are reversible
Ligand-receptor complexes are most often formed in cell communication pathways in which participating cells are in direct contact
Question 5
SURVEY
30 seconds
Q. When epinephrine binds to cardiac (heart) muscle cells, it speeds their contraction. When it binds to muscle cells of the small intestine, it inhibits their contraction. Which of the following best accounts for the fact that the same hormone can have different effects on muscle cells?
answer choices
Cardiac cells have more receptors for epinephrine than do intestinal cells
Epinephrine circulates to the heart first and thus is in higher concentration around cardiac cells
The two types of muscle cells have different signal transduction pathways for epinephrine and thus have different cellular responses
Cardiac muscle is stronger than intestinal muscle and thus has a stronger response to epinephrine
Question 6
SURVEY
60 seconds
Q. Which of the following can activate a protein by transferring a phosphate group to it?
answer choices
cAMP
G Protein
protein kinase
protein phosphatase
Question 7
SURVEY
60 seconds
Q. What do second messengers do?
answer choices
transport a signal molecule through the lipid bilayer and into the cytoplasm
relay a message from the receptor of the first messenger throughout the cytoplasm
transmit a message from the outside of the membrane to the extracellular fluid
produce a cellular response such as the production of a protein
Question 8
SURVEY
60 seconds
Q. Signal amplification is most often achieved by
answer choices
an enzyme cascade
binding of multiple signals
branching pathways
action of adenylyl cyclase
Question 9
SURVEY
30 seconds
Q. Which of the following is an example of a second messenger?
answer choices
cAMP
GTP
insulin
epinephrine
Question 10
SURVEY
30 seconds
Q. Cell signaling involves converting extracellular signals to specific responses inside the target cell. Which of the following best describes how a cell initially responds to a signal?
answer choices
The cell experiences a change in receptor conformation
The cell experiences an influx of ions
The cell experiences an increase in protein kinase activity
The cell experiences G protein activation
Question 11
SURVEY
60 seconds
Q. What is a G protein?
answer choices
specific type of membrane-receptor protein
protein on the cytoplasmic side of a membrane
membrane-bound enzyme
relay protein
Question 12
SURVEY
60 seconds
Q. Which of the following can activate a protein by transferring a phosphate group to it?
answer choices
cAMP
G Protein
protein kinase
protein phosphatase
Question 13
SURVEY
30 seconds
Q. Epinephrine (also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. The model for the action of Epinephrine is shown below. Which of the following molecules act as a second messenger in the cascade by which epinephrine stimulates the activation of the enzyme glycogen phosphorylase?
answer choices
Adenosine
Adenylyl cyclase
Citric acid
Cyclic AMP
Question 14
SURVEY
30 seconds
Q. Epinephrine (also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. The model for the action of Epinephrine is shown below. Which of the following represents the correct ordering of the molecules that are activated by a single molecule of epinephrine, from highest number of molecules to lowest number of molecules?
answer choices
cAMP, protein kinase A, phosphorylase kinase, glycogen phosphorylase
Glycogen phosphorylase, phosphorylase kinase, protein kinase A, cAMP
cAMP, phosphorylase kinase, glycogen phosphorylase, protein kinase A
Glycogen phosphorylase, cAMP, protein kinase A, phosphorylase kinase
Question 15
SURVEY
30 seconds
Q. Epinephrine (also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. The model for the action of Epinephrine is shown below. Which of the following would likely not be observed in a person injected with epinephrine?
answer choices
Decreased production of cAMP in liver cells
Inactivation of glycogen synthase
Increased glucose mobilization
Activation of G proteins
Question 16
SURVEY
30 seconds
Q. Epinephrine (also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. The model for the action of Epinephrine is shown below. Which of the following best describes a benefit of the many steps involved in a protein kinase cascade?
answer choices
It allows for the activation or inhibition of many enzymes.
It allows for the amplification of the signal.
It allows for the distribution of the signal throughout the inside of the cell.
All of the above.
Question 17
SURVEY
30 seconds
Q. Epinephrine (also known as adrenaline or adrenalin) is a hormone and a neurotransmitter. The model for the action of Epinephrine is shown below. All of the following are enzymes involved in the signal transduction pathway shown EXCEPT
answer choices
adenyl cyclase
protein kinase A
phosphorylase kinase
epinephrine
Question 18
SURVEY
30 seconds
Q. G proteins are a family of proteins involved in transmitting chemical messages originating from outside a cell into the inside of the cell. G proteins function as molecular switches. Which of the following best describes the role in which the G protein is most intimately involved in the process shown above?
answer choices
Production of the ligand molecule.
Reception of the signal.
Transduction of the signal.
Production of response to signal.
Question 19
SURVEY
30 seconds
Q. G proteins are a family of proteins involved in transmitting chemical messages originating from outside a cell into the inside of the cell. G proteins function as molecular switches. Investigations into the causes behind symptoms in Alzheimer’s patients have led to the hypothesis that the disease may be caused by excessive activity of IP3 second messengers in brain cells. When comparing cell samples of Alzheimer’s patients to those taken from the control group, which of the following pieces of evidence would support this hypothesis?
answer choices
A lower number of receptor proteins in the Alzheimer cell samples.
A greater volume of endoplasmic reticulum membrane in the control group cell samples.
A higher concentration of calcium ions in the cytosol of the Alzheimer cell samples.
A lower number of activated proteins in the cytosol of the Alzheimer cell samples
Question 20
SURVEY
30 seconds
Q. The term steroid describes both hormones produced by the body and artificially produced medications that duplicate the action for the naturally occurring steroids. All of the following describe steroid hormones EXCEPT:
answer choices
A. They bind with receptor proteins in the plasma membrane to trigger cellular responses.
A. They are derived from cholesterol and are lipid soluble.
They serve as ligands in signal transduction pathways
A. They are exemplified by testosterone, estrogen and progesterone
Question 21
SURVEY
30 seconds
Q. Which areas in the diagram depict the process of transduction in the signal transduction pathway of cell communication?
answer choices
Q and R
Q and U
S and T
T and U
Question 22
SURVEY
30 seconds
Q. The data shown was collected in an experiment designed to test the hypothesis that a second messenger mediates between receptor activation at the plasma membrane and enzyme activation in the cytoplasm. Liver tissue was homogenated and used to make three test solutions; a whole homogenate, a fraction containing plasma membrane and a fraction containing cytoplasm but no plasma membrane. Which of the following would be a reasonable conclusion based on the data collected?
answer choices
All cells in an organism respond to the presence of epinephrine via second messengers present in the homogenate
A soluble second messenger, produced by hormone-actived membranes is present in the solution and activates enzymes in the cytoplasm
Epinephrine is a hormone found bound in the membrane of cells and requires a ligand to stimulate its transduction
An epineprine signal transduction pathway works more efficiently at warmer temperatures
Question 23
SURVEY
60 seconds
Q. What is a G protein?
answer choices
specific type of membrane-receptor protein
protein on the cytoplasmic side of a membrane
membrane-bound enzyme
relay protein
Question 24
SURVEY
60 seconds
Q. Which of the following is involved in many human medicines for disease?
answer choices
cAMP
Calcium concentration
G-protein pathways
receptor tyrosine kinases
Question 25
SURVEY
60 seconds
Q. What does a protein phosphatase do?
answer choices
removes phosphates
transfers phosphates from ATP to proteins
activates an enzyme with a signal molecule
Question 26
SURVEY
60 seconds
Q. What is a phosphorylation cascade?
answer choices
travelling of hormones through the blood
facilitated diffusion of hydrophilic molecules through a channel protein
the removal of a phosphate from a molecule
a series of molecules that are sequentially phosphorylated
Question 27
SURVEY
30 seconds
Q. What activates adenylyl cyclase?
answer choices
epinephrine binding to it
an activated G protein
cAMP
a protein kinase
Question 28
SURVEY
30 seconds
Q. What is the mechanism of protein kinases?
answer choices
activate proteins by dephosphorylating them
activate proteins with cAMP
change membrane potential
activate proteins by phosphorylating them
Question 29
SURVEY
30 seconds
Q. What is one effect epinephrine has on liver cells?
answer choices
uptake glucose to store as glycogen
break glycogen down to release glucose
decreases blood vessel diameter
decreases blood glucose levels
Question 30
SURVEY
60 seconds
Q. Which of the following is a chemical message that usually travels through the bloodstream to target cells?
answer choices
hormone
local regulator
neurotransmitter
second messenger
Question 31
SURVEY
60 seconds
Q. What is a function of the second messenger IP3?
answer choices
bind to and activate protein kinase A
activate transcription factors
convert ATP to cAMP
bind to and open ligand-gated channels
Question 32
SURVEY
30 seconds
Q. G proteins are regulated by which molecule?
answer choices
GTP
ATP
inorganic phosphate
Glucose
Question 33
SURVEY
30 seconds
Q. Which is a common second messenger?
answer choices
cAMP
Na+
K+
G Protein
Question 34
SURVEY
30 seconds
Q. Tyrosine kinases are responsible for transferring which molecule?
answer choices
phosphate
oxygen
hydrogen
ADP
Question 35
SURVEY
30 seconds
Q. What class of macromolecules includes transcription factors?
answer choices
carbohydrates
nucleic acids
proteins
lipids
Question 36
SURVEY
60 seconds
Q. Which of the following would be an example of paracrine signaling in animals?
answer choices
neurotransmitter acetylcholine
hormone epinephrine
neurotransmitter norepinephrine
growth factor
Question 37
SURVEY
60 seconds
Q. What determines whether a cell is a target cell for a particular signal molecule?
answer choices
phosphorylation cascade
cAMP
signal receptors
phosphatase
Question 38
SURVEY
60 seconds
Q. What determines whether a signal molecule binds on the surface or enters the cell?
answer choices
size
polarity
ability to cross the membrane
all of these are correct
Question 39
SURVEY
30 seconds
Q. What is a benefit of signal transduction pathways?
answer choices
they prevent cells from communicating with each other
they help cells to perform hydrolysis
they lower activation energy required for metabolic reactions
they enable cells to amplify a message from a signal molecule
Question 40
SURVEY
60 seconds
Q. Which of the following converts cAMP to AMP?
answer choices
phosphodiesterase
protein phosphatase
GTPase
adenylyl cyclase
Question 41
SURVEY
30 seconds
Q. Local signalling between a signal releasing cell and neighboring cells is called
answer choices
hormonal
endocrine
synaptic
paracrine
Question 42
SURVEY
30 seconds
Q. A small signal molecule that specifically binds to a different, larger molecule is called a
answer choices
ligand
substrate
kinase
receptor
Question 43
SURVEY
30 seconds
Q. What are the properties of a signal molecule that is most likely to bind to a receptor that is on the outside of the cell membrane?
answer choices
small, nonpolar, hydrophobic
large, polar, hydrophilic
small, polar, hydrophilic
large, nonpolar, hydrophobic
Question 44
SURVEY
30 seconds
Q. Which of the following is a type of signal molecule that can pass through the lipid bilayer and bind to a receptor within the cytoplasm?
answer choices
protein
ion
steroid
water
Question 45
SURVEY
30 seconds
Q. Which of the following describes a transcription factor?
answer choices
It is a protein that can be activated by a signal and then cause the transcription of DNA to mRNA
It is a lipid that can diffuse directly through the plasma membrane and bind to a cytoplasmic receptor
It is a hydrophobic signal molecule that binds to a receptor on the external side of the cell membrane
It is a protein that determines whether or not a ribosome binds to the endoplasmic reticulum
Question 46
SURVEY
30 seconds
Q. Which of the following is a protein that can hold several other relay proteins as it binds to an activated membrane receptor?
answer choices
transcription factor
kinase
phosphatase
scaffold
Question 47
SURVEY
30 seconds
Q. Receptor tyrosine kinase is activated by
answer choices
dimerization
phosphorylation by 6 ATP
binding of 2 signal molecules
all of these are correct
Question 48
SURVEY
30 seconds
Q. Binding of a signal molecule to which type of receptor leads to a change in the concentration of ions on opposite sides of the plasma membrane?
answer choices
receptor tyrosine kinase
g-protein linked receptor
ligand-gated ion channel
second messenger
Question 49
SURVEY
30 seconds
Q. Which of the following is the best evidence that cell communication evolved early in the history of living things?
answer choices
they have receptors on the external surface of the cell membrane
they have receptors in the cytoplasm of cells
they can travel long distances
they are found in primitive cells
Question 50
SURVEY
30 seconds
Q. What does a cell require to respond to a certain signal molecule?
answer choices
receptor for the signal
scaffold protein
inactive enzyme
phosphorylation cascaed
Question 51
SURVEY
30 seconds
Q. Why did Sutherland's epinephrine experiment only work with intact liver cells?
answer choices
the intact cells contained a second messenger
the intact cells contained more glycogen
the intact cells had fewer receptors for epinephrine