Question 1

Which of the following statements concerning calmodulin is FALSE?

Accepted Answer

A)  It activates protein kinases. 
B)  It activates phosphatases. 
C)  It is a protein. 
D)  It is found in all eukaryotic cells studied. 
E)  It binds a maximum of three calcium ions. 
A)  It activates protein kinases. 
B)  It activates phosphatases. 
C)  It is a protein. 
D)  It is found in all eukaryotic cells studied. 
E)  It binds a maximum of three calcium ions. E

Question 2

An example of a neurotransmitter that opens ligand-gated sodium channels is:

Accepted Answer

A)  GABA. 
B)  acetylcholine. 
C)  ecdysone. 
D)  NO. 
E)  cortisol. 
A)  GABA. 
B)  acetylcholine. 
C)  ecdysone. 
D)  NO. 
E)  cortisol. B

Question 3

Ion channels are found in the plasma membranes of neurons and muscle cells.
__________________

Accepted Answer

A) True 
 B)False  True

Question 4

All of the following are examples of signal termination EXCEPT:

Accepted Answer

A)  one cAMP molecule activating many protein kinases. 
B)  phosphodiesterase converting cGMP to GTP. 
C)  GTPase converting GTP to GDP. 
D)  the inactivation of G protein by the cholera toxin. 
E)  phosphatase removing the phosphate group from a protein. 
A)  one cAMP molecule activating many protein kinases. 
B)  phosphodiesterase converting cGMP to GTP. 
C)  GTPase converting GTP to GDP. 
D)  the inactivation of G protein by the cholera toxin. 
E)  phosphatase removing the phosphate group from a protein.

Question 5

Which of the following statements concerning G protein is FALSE?

Accepted Answer

A)  Its subunits can separate. 
B)  One subunit is a GTPase. 
C)  One subunit binds GTP. 
D)  One subunit binds GDP. 
E)  One subunit binds ATP. 
A)  Its subunits can separate. 
B)  One subunit is a GTPase. 
C)  One subunit binds GTP. 
D)  One subunit binds GDP. 
E)  One subunit binds ATP.

Question 6

A major group of enzyme-linked receptors are:

Accepted Answer

A)  phospholipases. 
B)  adenylyl cyclases. 
C)  tyrosine kinases. 
D)  G proteins. 
E)  ion channels. 
A)  phospholipases. 
B)  adenylyl cyclases. 
C)  tyrosine kinases. 
D)  G proteins. 
E)  ion channels.

Question 7

Compare and contrast the structure and function of ion channel-linked receptors, G protein-linked receptors, and enzyme-linked receptors.In general, how do they differ from intracellular receptors?

Accepted Answer

Concepts to Consider: Ligand-g

Question 8

MATCHING
Match receptor with activated state.Answers should be used more than once.
a.Ion channel linked receptor
c.Enzyme linked receptor
b.G protein linked receptor
-Sodium ions enter the cell.

Accepted Answer

The answer of MATCHING
Match receptor with activated state.Answers should be...

Question 9

In the cAMP signal transduction pathway, once a protein kinase is activated, which of the following happens next?

Accepted Answer

A)  G protein is activated. 
B)  Adenylyl cyclase is activated. 
C)  GDP is replaced by GTP. 
D)  cAMP is converted to ATP. 
E)  The protein kinase activates a cellular response. 
A)  G protein is activated. 
B)  Adenylyl cyclase is activated. 
C)  GDP is replaced by GTP. 
D)  cAMP is converted to ATP. 
E)  The protein kinase activates a cellular response.

Question 10

Which of the following statements concerning calcium ions is FALSE?

Accepted Answer

A)  They are involved in fertilization, blood clotting, and microtubule disassembly. 
B)  Their concentration in the cytosol rises when Ca2+ gates open in the ER. 
C)  Their concentration in the cytosol is usually higher than in the extracellular fluid. 
D)  They can act by themselves, without binding to calmodulin. 
E)  They can exert an effect after binding to calmodulin. 
A)  They are involved in fertilization, blood clotting, and microtubule disassembly. 
B)  Their concentration in the cytosol rises when Ca2+ gates open in the ER. 
C)  Their concentration in the cytosol is usually higher than in the extracellular fluid. 
D)  They can act by themselves, without binding to calmodulin. 
E)  They can exert an effect after binding to calmodulin.

Question 11

Barbituates and benzodiazpine drugs bind to GABA receptors to open chloride channels, inhibit neural impulse, and induce tranquility.
__________________

Accepted Answer

A) True 
 B)False

Question 12

Compare and contrast local regulators, neurotransmitters, and hormones.

Accepted Answer

Local regulators help cells co

Question 13

In contrast to a G protein-linked receptor and an enzyme-linked receptor, a channel-linked receptor:

Accepted Answer

A)  is located on the cell surface. 
B)  is composed of seven alpha helices. 
C)  couples signaling molecules to signal transduction pathways. 
D)  is a ligand-gated channel. 
E)  functions as a tyrosine kinase. 
A)  is located on the cell surface. 
B)  is composed of seven alpha helices. 
C)  couples signaling molecules to signal transduction pathways. 
D)  is a ligand-gated channel. 
E)  functions as a tyrosine kinase.

Question 14

The outer part of the enzyme linked receptor has a binding site for a signaling molecule, and the part of the receptor that extends into the cytosol has a binding site for a specific G protein.
__________________

Accepted Answer

A) True 
 B)False

Question 15

The main signaling cascade for cell division and differentiation is the __________ cascade.

Accepted Answer

A)  phospholipase C 
B)  MAP kinase 
C)  phosphoinositol 
D)  cAMP 
E)  calcium-calmodulin 
A)  phospholipase C 
B)  MAP kinase 
C)  phosphoinositol 
D)  cAMP 
E)  calcium-calmodulin

Question 16

Under which of the following situations would receptor down-regulation most likely occur?

Accepted Answer

A)  The concentration of a neurotransmitter is too low. 
B)  The concentration of a hormone is too high. 
C)  The number of receptors in the plasma membrane is too low. 
D)  The number of G proteins is too high. 
E)  The cell is unable to manufacture cyclic AMP. 
A)  The concentration of a neurotransmitter is too low. 
B)  The concentration of a hormone is too high. 
C)  The number of receptors in the plasma membrane is too low. 
D)  The number of G proteins is too high. 
E)  The cell is unable to manufacture cyclic AMP.

Question 17

Choanoflagellates have been important for the study of cell communication evolution because choanoflagellates have:

Accepted Answer

A)  signal transduction pathways unlike those in other bacteria. 
B)  signaling molecules similar to those of other protists. 
C)  signal transduction pathways that interfere with the cells they infect. 
D)  protein kinases similar to those in animals. 
E)  G proteins different from those in prokaryotes. 
A)  signal transduction pathways unlike those in other bacteria. 
B)  signaling molecules similar to those of other protists. 
C)  signal transduction pathways that interfere with the cells they infect. 
D)  protein kinases similar to those in animals. 
E)  G proteins different from those in prokaryotes.

Question 18

Phospholipase C catalyzes the reaction in which:

Accepted Answer

A)  IP3 is converted to DAG. 
B)  PIP2 is split. 
C)  a protein kinase is activated. 
D)  calcium ions are released from the ER. 
E)  DAG is converted to PIP2. 
A)  IP3 is converted to DAG. 
B)  PIP2 is split. 
C)  a protein kinase is activated. 
D)  calcium ions are released from the ER. 
E)  DAG is converted to PIP2.

Question 19

MATCHING
Match receptor with activated state.Answers should be used more than once.
a.Ion channel linked receptor
c.Enzyme linked receptor
b.G protein linked receptor
-Protein kinase sites are active.

Accepted Answer

The answer of MATCHING
Match receptor with activated state.Answers should be...

Question 20

When a receptor binds to its G protein, which of the following happens next?

Accepted Answer

A)  The signaling molecule binds to the receptor. 
B)  The G protein activates an enzyme. 
C)  The three G protein subunits come together. 
D)  GTP is replaced by GDP. 
E)  GDP is replaced by GTP. 
A)  The signaling molecule binds to the receptor. 
B)  The G protein activates an enzyme. 
C)  The three G protein subunits come together. 
D)  GTP is replaced by GDP. 
E)  GDP is replaced by GTP.

Exam 6: Cell Communication

Which of the following statements concerning calmodulin is FALSE?

An example of a neurotransmitter that opens ligand-gated sodium channels is:

Ion channels are found in the plasma membranes of neurons and muscle cells. __________________

All of the following are examples of signal termination EXCEPT:

Which of the following statements concerning G protein is FALSE?

A major group of enzyme-linked receptors are:

Compare and contrast the structure and function of ion channel-linked receptors, G protein-linked receptors, and enzyme-linked receptors.In general, how do they differ from intracellular receptors?

MATCHING Match receptor with activated state.Answers should be used more than once. a.Ion channel linked receptor c.Enzyme linked receptor b.G protein linked receptor -Sodium ions enter the cell.

In the cAMP signal transduction pathway, once a protein kinase is activated, which of the following happens next?

Which of the following statements concerning calcium ions is FALSE?

Barbituates and benzodiazpine drugs bind to GABA receptors to open chloride channels, inhibit neural impulse, and induce tranquility. __________________

Compare and contrast local regulators, neurotransmitters, and hormones.

In contrast to a G protein-linked receptor and an enzyme-linked receptor, a channel-linked receptor:

The outer part of the enzyme linked receptor has a binding site for a signaling molecule, and the part of the receptor that extends into the cytosol has a binding site for a specific G protein. __________________

The main signaling cascade for cell division and differentiation is the __________ cascade.

Under which of the following situations would receptor down-regulation most likely occur?

Choanoflagellates have been important for the study of cell communication evolution because choanoflagellates have:

Phospholipase C catalyzes the reaction in which:

MATCHING Match receptor with activated state.Answers should be used more than once. a.Ion channel linked receptor c.Enzyme linked receptor b.G protein linked receptor -Protein kinase sites are active.

When a receptor binds to its G protein, which of the following happens next?

A View of Life

Atoms and Molecules: the Chemical Basis of Life

The Chemistry of Life: Organic Compounds

Organization of the Cell

Biological Membranes

Energy and Metabolism

How Cells Make Atp: Energy-Releasing Pathways

Photosynthesis: Capturing Light Energy

Chromosomes, Mitosis, and Meiosis

The Basic Principles of Heredity

Dna: the Carrier of Genetic Information

Gene Expression

Gene Regulation

Dna Technology and Genomics

Human Genetics and the Human Genome

Developmental Genetics

Introduction to Darwinian Evolution

Evolutionary Change in Populations

Speciation and Macroevolution

The Origin and Evolutionary History of Life

The Evolution of Primates

Understanding Diversity: Systematics

Viruses and Subviral Agents

Bacteria and Archaea

Protists

Seedless Plants

Seed Plants

The Fungi

An Introduction to Animal Diversity

Sponges, Cnidarians, Ctenophores, and Protostomes

The Deuterostomes

Plant Structure, Growth, and Development

Leaf Structure and Function

Stem Structure and Transport

Roots and Mineral Nutrition

Reproduction in Flowering Plants

Plant Developmental Responses to External and Internal Signals

Animal Structure and Function: an Introduction

Protection, Support, and Movement

Neural Signaling

Neural Regulation

Sensory Systems

Internal Transport

The Immune System: Internal Defense

Gas Exchange

Processing Food and Nutrition

Osmoregulation and Disposal of Metabolic Wastes

Endocrine Regulation

Reproduction

Animal Development

Animal Behavior

Introduction to Ecology: Population Ecology

Community Ecology

Ecosystems and the Biosphere

Ecology and the Geography of Life

Biological Diversity and Conservation Biology

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