Question 1

Quorum sensing would most likely occur when:

Accepted Answer

A)  Dictyostelium senses cyclic AMP. 
B)  tobacco plants are attacked by insects. 
C)  bacteria reach a certain critical concentration. 
D)  predator insects eat herbivorous insects. 
E)  insulin binds to target cells. 
A)  Dictyostelium senses cyclic AMP. 
B)  tobacco plants are attacked by insects. 
C)  bacteria reach a certain critical concentration. 
D)  predator insects eat herbivorous insects. 
E)  insulin binds to target cells.

Question 2

Which of the following is NOT an example of an enzyme-linked receptor?

Accepted Answer

A)  a tyrosine kinase 
B)  the brassinolide receptor 
C)  the GABA receptor 
D)  the ethylene receptor 
E)  a histidine kinase 
A)  a tyrosine kinase 
B)  the brassinolide receptor 
C)  the GABA receptor 
D)  the ethylene receptor 
E)  a histidine kinase

Question 3

What is the difference between a first messenger and a second messenger? Give an example of each.

Accepted Answer

The first messenger binds the inital rec

Question 4

Which of the following statements concerning intracellular receptors is FALSE?

Accepted Answer

A)  Some bind hydrophobic signaling molecules. 
B)  Some function as transcription factors. 
C)  They diffuse across the plasma membrane of target cells. 
D)  The ligand-receptor complex can activate genes. 
E)  The ligand-receptor complex can inactivate genes. 
A)  Some bind hydrophobic signaling molecules. 
B)  Some function as transcription factors. 
C)  They diffuse across the plasma membrane of target cells. 
D)  The ligand-receptor complex can activate genes. 
E)  The ligand-receptor complex can inactivate genes.

Question 5

Scaffold proteins organize groups of intracellular signaling kinases into signaling complexes.
__________________

Accepted Answer

A) True 
 B)False

Question 6

The function of scaffolding proteins is to:

Accepted Answer

A)  phosphorylate proteins in a cascade. 
B)  dephosphorylate proteins in a cascade. 
C)  convert ATP and GTP to cAMP and cGMP, respectively. 
D)  regulate the MAP kinase pathway. 
E)  stimulate the release of calcium ions from the ER. 
A)  phosphorylate proteins in a cascade. 
B)  dephosphorylate proteins in a cascade. 
C)  convert ATP and GTP to cAMP and cGMP, respectively. 
D)  regulate the MAP kinase pathway. 
E)  stimulate the release of calcium ions from the ER.

Question 7

A receptor on the cell surface usually has several domains.The function of the external domain is:

Accepted Answer

A)  transmitting the signal to the inside of the cell. 
B)  holding the receptor within the membrane. 
C)  attaching the receptor to the DNA. 
D)  functioning as an enzyme. 
E)  binding the signaling molecule. 
A)  transmitting the signal to the inside of the cell. 
B)  holding the receptor within the membrane. 
C)  attaching the receptor to the DNA. 
D)  functioning as an enzyme. 
E)  binding the signaling molecule.

Question 8

An example of a signaling molecule that binds with a receptor on the cell surface is:

Accepted Answer

A)  insulin. 
B)  ecdysone. 
C)  Vitamin D. 
D)  Vitamin A. 
E)  nitric oxide. 
A)  insulin. 
B)  ecdysone. 
C)  Vitamin D. 
D)  Vitamin A. 
E)  nitric oxide.

Question 9

Adenylyl cyclase catalyzes the reaction in which:

Accepted Answer

A)  a protein is phosphorylated. 
B)  ATP is converted to cAMP. 
C)  GTP is converted to GDP. 
D)  PIP2 is split. 
E)  calcium ions bind calmodulin. 
A)  a protein is phosphorylated. 
B)  ATP is converted to cAMP. 
C)  GTP is converted to GDP. 
D)  PIP2 is split. 
E)  calcium ions bind calmodulin.

Question 10

In the phospholipase C signal transduction pathway, which are second messengers?

Accepted Answer

A)  phospholipase C and G protein 
B)  PIP2 and IP3 
C)  cAMP and IP3 
D)  phospholipase C and protein kinase A 
E)  IP3 and DAG 
A)  phospholipase C and G protein 
B)  PIP2 and IP3 
C)  cAMP and IP3 
D)  phospholipase C and protein kinase A 
E)  IP3 and DAG

Question 11

Which of the following statements concerning receptors is FALSE?

Accepted Answer

A)  They are found inside the cell and on the cell surface. 
B)  They are proteins or glycoproteins. 
C)  They are also called ligands. 
D)  They are highly selective. 
E)  They are activated by binding to a signaling molecule. 
A)  They are found inside the cell and on the cell surface. 
B)  They are proteins or glycoproteins. 
C)  They are also called ligands. 
D)  They are highly selective. 
E)  They are activated by binding to a signaling molecule.

Question 12

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
-GDP is replaced with GTP.

Accepted Answer

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

Question 13

In the IP3 pathway, what is the function of IP3?

Accepted Answer

A)  activate protein kinase C 
B)  activate phospholipase C 
C)  phosphorylate a protein 
D)  bind calcium channels in the ER 
E)  activate adenylyl cyclase 
A)  activate protein kinase C 
B)  activate phospholipase C 
C)  phosphorylate a protein 
D)  bind calcium channels in the ER 
E)  activate adenylyl cyclase

Question 14

In what part of the cell does a polar signaling molecule bind its receptor? A nonpolar signaling molecule? Explain your reasoning.

Accepted Answer

Polar signaling molecules bind membrane

Question 15

Which of the following lists the correct sequence of events involved in cell signaling?

Accepted Answer

A)  amplifying, signal transducing, receiving, responding 
B)  signal transducing, sending, receiving, terminating 
C)  sending, signal transducing, receiving, amplifying 
D)  receiving, sending, signal transducing, responding 
E)  sending, receiving, signal transducing, responding 
A)  amplifying, signal transducing, receiving, responding 
B)  signal transducing, sending, receiving, terminating 
C)  sending, signal transducing, receiving, amplifying 
D)  receiving, sending, signal transducing, responding 
E)  sending, receiving, signal transducing, responding

Question 16

Which of the following statements concerning intracellular receptors is FALSE?

Accepted Answer

A)  Their ligands are hydrophobic. 
B)  Most are transcription factors. 
C)  Some are located in the cytosol. 
D)  After binding their ligand, they move out of the cell. 
E)  Some are bound to DNA. 
A)  Their ligands are hydrophobic. 
B)  Most are transcription factors. 
C)  Some are located in the cytosol. 
D)  After binding their ligand, they move out of the cell. 
E)  Some are bound to DNA.

Question 17

In the signal transduction pathway involving cAMP, once cAMP is formed, it then activates:

Accepted Answer

A)  protein kinase A. 
B)  adenylyl cyclase. 
C)  G protein. 
D)  protein kinase C. 
E)  IP3. 
A)  protein kinase A. 
B)  adenylyl cyclase. 
C)  G protein. 
D)  protein kinase C. 
E)  IP3.

Question 18

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
-Explain the differences between receptor up-regulation and down-regulation including the conditions under which a cell would use one rather than the other.

Accepted Answer

Concepts to Consider: Receptor

Question 19

A receptor in plant cells that responds to red light is:

Accepted Answer

A)  brassinolide. 
B)  diacylglycerol. 
C)  rhodopsin. 
D)  cryptochrome. 
E)  phytochrome. 
A)  brassinolide. 
B)  diacylglycerol. 
C)  rhodopsin. 
D)  cryptochrome. 
E)  phytochrome.

Question 20

Which of the following is released by cells lining blood vessels and causes a decrease in blood pressure?

Accepted Answer

A)  histamine 
B)  acetylcholine 
C)  cyclic AMP 
D)  nitric oxide 
E)  prostaglandin 
A)  histamine 
B)  acetylcholine 
C)  cyclic AMP 
D)  nitric oxide 
E)  prostaglandin

Exam 6: Cell Communication

Quorum sensing would most likely occur when:

Which of the following is NOT an example of an enzyme-linked receptor?

What is the difference between a first messenger and a second messenger? Give an example of each.

Which of the following statements concerning intracellular receptors is FALSE?

Scaffold proteins organize groups of intracellular signaling kinases into signaling complexes. __________________

The function of scaffolding proteins is to:

A receptor on the cell surface usually has several domains.The function of the external domain is:

An example of a signaling molecule that binds with a receptor on the cell surface is:

Adenylyl cyclase catalyzes the reaction in which:

In the phospholipase C signal transduction pathway, which are second messengers?

Which of the following statements concerning receptors is FALSE?

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 -GDP is replaced with GTP.

In the IP3 pathway, what is the function of IP3?

In what part of the cell does a polar signaling molecule bind its receptor? A nonpolar signaling molecule? Explain your reasoning.

Which of the following lists the correct sequence of events involved in cell signaling?

Which of the following statements concerning intracellular receptors is FALSE?

In the signal transduction pathway involving cAMP, once cAMP is formed, it then activates:

A receptor in plant cells that responds to red light is:

Which of the following is released by cells lining blood vessels and causes a decrease in blood pressure?

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

Filters

In the IP₃ pathway, what is the function of IP₃?