Question 1

Cytoplasmic receptors bind
A) small signals that can diffuse through the plasma membrane.
B) secondary messengers, such as cAMP.
C) hydrophilic molecules.
D) ligands.
E) All of the above

Accepted Answer

The answer of Cytoplasmic receptors bind
A) small signals that can...

Question 2

Used to treat bipolar disorder, _______ acts by inhibiting the G protein activation of phospholipase C.

Accepted Answer

The answer of Used to treat bipolar disorder, _______ acts...

Question 3

Caffeine is a stimulant that works because it acts as a(n) _______ to the adenosine receptors in a person's brain, and stimulates _______ in that person's heart and liver that increases blood flow and blood glucose.
A) effector; a pathway
B) inhibitor; a cascade pathway
C) inhibitor; a ligand
D) signal; inhibitors
E) pathway; a ligand

Accepted Answer

Caffeine is an inhibitor to adenosine receptors in the brain, which normally bind to adenosine and cause drowsiness. By blocking these receptors, caffeine helps to keep a person alert. Caffeine also stimulates a cascade pathway in the heart and liver, which leads to increased blood flow and blood glucose levels.

Question 4

_______ is a second messenger found in the pathway by which epinephrine activates the liver enzyme that breaks down glycogen.

Accepted Answer

The answer of _______ is a second messenger found in...

Question 5

Draw what would happen when a hormone binds to a receptor, as shown in the diagram below.

Accepted Answer

The answer of Draw what would happen when a hormone...

Question 6

Which of the following does not occur during signal transduction?
A) Binding of ligand to receptor
B) Conformational change to the receptor protein
C) Conformational change of the signal
D) Alteration of cellular activity
E) Conformational change in the ligand

Accepted Answer

Signal transduction involves the binding of a ligand to a receptor, causing a conformational change in the receptor, which then leads to alterations in cellular activity. The signal itself does not undergo a conformational change.

Question 7

E. coli cells respond to osmotic changes by
A) changing the permeability of the membrane.
B) changing the DNA that is transcribed.
C) phosphorylating OmpR.
D) binding the ligand to EnvZ.
E) increasing metabolism.

Accepted Answer

E. coli cells respond to osmotic changes by changing the permeability of the membrane. This allows the cells to regulate the flow of water and solutes in and out of the cell, thus maintaining proper osmotic balance.

Question 8

Signal binding to a receptor differs from enzyme-substrate binding in that
A) in signal binding the signal is not altered during the process.
B) the single-binding process is reversible.
C) in signal binding, cell receptors can become saturated by signal molecules.
D) signal binding can be inhibited by an antagonist.
E) None of the above

Accepted Answer

In signal binding, the signal molecule (ligand) is not altered during the process, while in enzyme-substrate binding, the substrate molecule is altered or modified by the enzyme. The other options listed (B-D) are applicable to both signal binding and enzyme-substrate binding.

Question 9

The second messenger involved in the therapeutic use of Viagra is _______.

Accepted Answer

The answer of The second messenger involved in the therapeutic...

Question 10

Which of the following statements about secondary messengers is true?
A) They amplify the signal.
B) They bind to the active site of the receptor.
C) They result in multiple effects from a single signal.
D) Both a and c
E) All of the above

Accepted Answer

Secondary messengers amplify the signal and result in multiple effects from a single signal, but they do not bind to the active site of the receptor. Therefore, option B is incorrect, and option E is too broad.

Question 11

The enzyme phospholipase C breaks down PIP2 into two molecules, _______ and _______, both of which can function as second messengers.

Accepted Answer

The answer of The enzyme phospholipase C breaks down PIP2...

Question 12

What do G protein-linked receptors and protein kinases have in common?
A) Ligand binding
B) Conformational change once the ligand is bound
C) Amplification of the signal
D) All of the above
E) None of the above

Accepted Answer

Both G protein-linked receptors and protein kinases undergo ligand binding and conformational changes upon ligand binding. Additionally, both systems can lead to amplification of the signal. Therefore, all of the above options are correct.

Question 13

Which of the following statements about protein kinase cascades is true?
A) Amplification can occur at each step in the path.
B) Information at the plasma membrane is communicated to the nucleus.
C) The multiple steps allow for specificity of the process.
D) Different targets can produce variation in the cellular response.
E) All of the above

Accepted Answer

All of the statements are true. Protein kinase cascades amplify signals, allowing for communication between the plasma membrane and the nucleus, and provide specificity by using different targets to produce different cellular responses.

Question 14

The plasmodesma is partially filled with a tubule called the _______.

Accepted Answer

The answer of The plasmodesma is partially filled with a...

Question 15

Which of the following statements about receptors is true?
A) Receptors are only found on the surface of cells.
B) Receptors are specific to the signal ligand.
C) Most receptors can bind with many signal ligands.
D) All receptors can act as ion channels.
E) All of the above

Accepted Answer

Receptors are specific to the signal ligand, meaning that they will only bind to a specific molecule or group of molecules. While some receptors are found on the surface of cells, others are located within the cell itself. Not all receptors act as ion channels, as there are many different types of receptors with varying functions. Therefore, options A, C, and D are not entirely accurate.

Question 16

The entry of a sperm into an egg causes a massive opening of _______ channels.

Accepted Answer

The answer of The entry of a sperm into an...

Question 17

In the diagram below, where and how would lithium interact with the pathway?

Accepted Answer

The answer of In the diagram below, where and how...

Question 18

A protein found in abnormal form in many human bladder cancer cells, _______, is a G protein.

Accepted Answer

The answer of A protein found in abnormal form in...

Question 19

Which of the following is not part of the IP₃ / DAG pathway? A) The binding of a hormone to a receptor B) The production of IP₃ by a G protein C) Activation of phospholipase C D) The opening of Ca²⁺ channels E) All of the above are part of the pathway.

Accepted Answer

The production of IP3 is not directly done by a G protein; instead, the G protein activates phospholipase C, which then produces IP3.

Question 20

The binding of a single molecule of epinephrine to a receptor can result in the activation of 1,000 molecules of glycogen phosphorylase. This result of the signaling transduction cascade is an example of the phenomenon known as _______.

Accepted Answer

The answer of The binding of a single molecule of...

Quiz 7: Cell Signaling and Communication

Cytoplasmic receptors bind

Used to treat bipolar disorder, _______ acts by inhibiting the G protein activation of phospholipase C.

Caffeine is a stimulant that works because it acts as a(n) _ to the adenosine receptors in a person's brain, and stimulates _ in that person's heart and liver that increases blood flow and blood glucose.

_______ is a second messenger found in the pathway by which epinephrine activates the liver enzyme that breaks down glycogen.

Draw what would happen when a hormone binds to a receptor, as shown in the diagram below.

Which of the following does not occur during signal transduction?

E. coli cells respond to osmotic changes by

Signal binding to a receptor differs from enzyme-substrate binding in that

The second messenger involved in the therapeutic use of Viagra is _______.

Which of the following statements about secondary messengers is true?

The enzyme phospholipase C breaks down PIP2 into two molecules, _ and _, both of which can function as second messengers.

What do G protein-linked receptors and protein kinases have in common?

Which of the following statements about protein kinase cascades is true?

The plasmodesma is partially filled with a tubule called the _______.

Which of the following statements about receptors is true?

The entry of a sperm into an egg causes a massive opening of _______ channels.

In the diagram below, where and how would lithium interact with the pathway?

A protein found in abnormal form in many human bladder cancer cells, _______, is a G protein.

Which of the following is not part of the IP₃ / DAG pathway?

The binding of a single molecule of epinephrine to a receptor can result in the activation of 1,000 molecules of glycogen phosphorylase. This result of the signaling transduction cascade is an example of the phenomenon known as _______.

Quiz 7: Cell Signaling and Communication

Cytoplasmic receptors bind

Used to treat bipolar disorder, _______ acts by inhibiting the G protein activation of phospholipase C.

Caffeine is a stimulant that works because it acts as a(n) _______ to the adenosine receptors in a person's brain, and stimulates _______ in that person's heart and liver that increases blood flow and blood glucose.

_______ is a second messenger found in the pathway by which epinephrine activates the liver enzyme that breaks down glycogen.

Draw what would happen when a hormone binds to a receptor, as shown in the diagram below.

Which of the following does not occur during signal transduction?

E. coli cells respond to osmotic changes by

Signal binding to a receptor differs from enzyme-substrate binding in that

The second messenger involved in the therapeutic use of Viagra is _______.

Which of the following statements about secondary messengers is true?

The enzyme phospholipase C breaks down PIP2 into two molecules, _______ and _______, both of which can function as second messengers.

What do G protein-linked receptors and protein kinases have in common?

Which of the following statements about protein kinase cascades is true?

The plasmodesma is partially filled with a tubule called the _______.

Which of the following statements about receptors is true?

The entry of a sperm into an egg causes a massive opening of _______ channels.

In the diagram below, where and how would lithium interact with the pathway?

A protein found in abnormal form in many human bladder cancer cells, _______, is a G protein.

Which of the following is not part of the IP3 / DAG pathway?

The binding of a single molecule of epinephrine to a receptor can result in the activation of 1,000 molecules of glycogen phosphorylase. This result of the signaling transduction cascade is an example of the phenomenon known as _______.

Caffeine is a stimulant that works because it acts as a(n) _ to the adenosine receptors in a person's brain, and stimulates _ in that person's heart and liver that increases blood flow and blood glucose.

The enzyme phospholipase C breaks down PIP2 into two molecules, _ and _, both of which can function as second messengers.

Which of the following is not part of the IP₃ / DAG pathway?