Question 1

Signaling molecules bind to the ____ region of a receptor tyrosine kinase.

Accepted Answer

A)  intracellular 
B)  hydrophobic 
C)  extracellular 
D)  cytoplasmic 
E)  intramembrane 
A)  intracellular 
B)  hydrophobic 
C)  extracellular 
D)  cytoplasmic 
E)  intramembrane

Question 2

After the binding of a signaling molecule to a surface receptor, the signaling molecule does not enter the cell.

Accepted Answer

A) True 
 B)False

Question 3

The recognition of a chemical signal by a receptor protein in the membrane is most similar to ____.

Accepted Answer

A)  mRNA specifying the sequence of amino acids in a polypeptide 
B)  binding of a specific substrate to the active site of an enzyme 
C)  turning on gene transcription 
D)  allosteric regulation of proteins 
E)  an enzyme requiring a specific optimum pH and temperature for activity 
A)  mRNA specifying the sequence of amino acids in a polypeptide 
B)  binding of a specific substrate to the active site of an enzyme 
C)  turning on gene transcription 
D)  allosteric regulation of proteins 
E)  an enzyme requiring a specific optimum pH and temperature for activity

Question 4

How do cells distinguish between estrogen and testosterone?

Accepted Answer

A)  Only male cells respond to testosterone, and female cells respond to estrogen. 
B)  Eestrogen is hydrophilic and binds to surface receptors, while testosterone is hydrophobic and binds to internal receptors. 
C)  Eestrogen and testosterone have similar functional groups but different basic structures that are easily distinguished by their individual receptors. 
D)  Estrogen and testosterone have the same basic structures, but different side chains that are easily distinguished by their individual receptors. 
E)  Estrogen and testosterone bind to different carrier proteins, which help receptors distinguish between the two molecules. 
A)  Only male cells respond to testosterone, and female cells respond to estrogen. 
B)  Eestrogen is hydrophilic and binds to surface receptors, while testosterone is hydrophobic and binds to internal receptors. 
C)  Eestrogen and testosterone have similar functional groups but different basic structures that are easily distinguished by their individual receptors. 
D)  Estrogen and testosterone have the same basic structures, but different side chains that are easily distinguished by their individual receptors. 
E)  Estrogen and testosterone bind to different carrier proteins, which help receptors distinguish between the two molecules.

Question 5

In breast cancer, ERα is often lost, which increases cell proliferation.

Accepted Answer

A) True 
 B)False

Question 6

What happens immediately after a signaling molecule binds to an RTK?

Accepted Answer

A)  receptor dimerization 
B)  receptor trimerization 
C)  receptor denaturation 
D)  receptor polymerization 
E)  receptor hydrolysis 
A)  receptor dimerization 
B)  receptor trimerization 
C)  receptor denaturation 
D)  receptor polymerization 
E)  receptor hydrolysis

Question 7

Cell signaling pathways evolved ____.

Accepted Answer

A)  thousands of years ago 
B)  in multicellular organisms 
C)  hundreds of millions of years ago 
D)  tens of billions of years ago 
E)  1 million years ago 
A)  thousands of years ago 
B)  in multicellular organisms 
C)  hundreds of millions of years ago 
D)  tens of billions of years ago 
E)  1 million years ago

Question 8

The amino acid targets of protein kinases in all GPCR pathways are ____.

Accepted Answer

A)  serine and glycine 
B)  serine and tyrosine 
C)  serine and threonine 
D)  glycine and tyrosine 
E)  glycine and threonine 
A)  serine and glycine 
B)  serine and tyrosine 
C)  serine and threonine 
D)  glycine and tyrosine 
E)  glycine and threonine

Question 9

What is the function of signal transduction?

Accepted Answer

Signal transduction refers to the proces

Question 10

In the first step of signal transduction, what is the trigger for the cellular response?

Accepted Answer

A)  target protein 
B)  kinase 
C)  ligand 
D)  second messenger 
E)  effector 
A)  target protein 
B)  kinase 
C)  ligand 
D)  second messenger 
E)  effector

Question 11

Why is cell communication considered evolutionarily ancient?

Accepted Answer

Some protein components of cell communic

Question 12

What is the second step of signal transduction?

Accepted Answer

A)  reception 
B)  transduction 
C)  differentiation 
D)  division 
E)  response 
A)  reception 
B)  transduction 
C)  differentiation 
D)  division 
E)  response

Question 13

Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____.

Accepted Answer

A)  autocrine signaling 
B)  paracrine signaling 
C)  long-distance signaling 
D)  local signaling 
E)  communication by direct contact 
A)  autocrine signaling 
B)  paracrine signaling 
C)  long-distance signaling 
D)  local signaling 
E)  communication by direct contact

Question 14

Many signal transduction pathways utilize second messengers to ____.

Accepted Answer

A)  transport a signal through the lipid bilayer of the plasma membrane 
B)  relay a signal from the outside of the cell to the inside 
C)  relay a signal from the inside of the cell to the outside 
D)  decrease the message once the signaling molecules have left the receptor 
E)  relay the message from the inner surface of the plasma membrane throughout the cytoplasm 
A)  transport a signal through the lipid bilayer of the plasma membrane 
B)  relay a signal from the outside of the cell to the inside 
C)  relay a signal from the inside of the cell to the outside 
D)  decrease the message once the signaling molecules have left the receptor 
E)  relay the message from the inner surface of the plasma membrane throughout the cytoplasm

Question 15

Receptors for polar molecules are found ____, while receptors for nonpolar molecules are located ____.

Accepted Answer

A)  on the cell surface; within the cell 
B)  within the cell; on the cell surface 
C)  on the cell surface; on the nuclear membrane 
D)  on the nuclear membrane; on the cell surface 
E)  on the cell surface; within the lipid bilayer 
A)  on the cell surface; within the cell 
B)  within the cell; on the cell surface 
C)  on the cell surface; on the nuclear membrane 
D)  on the nuclear membrane; on the cell surface 
E)  on the cell surface; within the lipid bilayer

Question 16

Quorum sensing ____.

Accepted Answer

A)  allows receptors from different parts of the cell to work together to elicit a response 
B)  allows receptors from different parts of the body to work together to elicit a response 
C)  uses multiple cellular pathways to elicit a specific response 
D)  is a type of communication between unicellular organisms 
E)  is a type of cell communication between multicellular organisms 
A)  allows receptors from different parts of the cell to work together to elicit a response 
B)  allows receptors from different parts of the body to work together to elicit a response 
C)  uses multiple cellular pathways to elicit a specific response 
D)  is a type of communication between unicellular organisms 
E)  is a type of cell communication between multicellular organisms

Question 17

Why are steroid hormones bound to carrier proteins in the blood?

Accepted Answer

A)  to prevent them from entering non-target cells 
B)  to keep them in an inactivate state 
C)  to mask hydrophobic groups on the steroids to allow for circulation in the blood 
D)  to help them bind to surface receptors and trigger a cellular response 
E)  to help them bind to surface receptors and trigger endocytosis 
A)  to prevent them from entering non-target cells 
B)  to keep them in an inactivate state 
C)  to mask hydrophobic groups on the steroids to allow for circulation in the blood 
D)  to help them bind to surface receptors and trigger a cellular response 
E)  to help them bind to surface receptors and trigger endocytosis

Question 18

Estrogen receptor (ER) α typically ____, while ERβ typically ____.

Accepted Answer

A)  stimulates DNA binding; inhibits DNA binding 
B)  stimulates cell proliferation; inhibits cell proliferation 
C)  stimulates channel opening; inhibits channel opening 
D)  inhibits DNA binding; stimulates DNA binding 
E)  inhibits cell proliferation; stimulates cell proliferation 
A)  stimulates DNA binding; inhibits DNA binding 
B)  stimulates cell proliferation; inhibits cell proliferation 
C)  stimulates channel opening; inhibits channel opening 
D)  inhibits DNA binding; stimulates DNA binding 
E)  inhibits cell proliferation; stimulates cell proliferation

Question 19

In order for a target cell to receive a signal, it must possess a ____ specific to the signaling molecule.

Accepted Answer

A)  glycolipid 
B)  glycoprotein 
C)  receptor 
D)  transfer protein 
E)  hormone 
A)  glycolipid 
B)  glycoprotein 
C)  receptor 
D)  transfer protein 
E)  hormone

Question 20

An active phosphatase adds phosphate groups to other molecules.

Accepted Answer

A) True 
 B)False

Exam 9: Cell Communication

Signaling molecules bind to the ____ region of a receptor tyrosine kinase.

After the binding of a signaling molecule to a surface receptor, the signaling molecule does not enter the cell.

The recognition of a chemical signal by a receptor protein in the membrane is most similar to ____.

How do cells distinguish between estrogen and testosterone?

In breast cancer, ERα is often lost, which increases cell proliferation.

What happens immediately after a signaling molecule binds to an RTK?

Cell signaling pathways evolved ____.

The amino acid targets of protein kinases in all GPCR pathways are ____.

What is the function of signal transduction?

In the first step of signal transduction, what is the trigger for the cellular response?

Why is cell communication considered evolutionarily ancient?

What is the second step of signal transduction?

Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____.

Many signal transduction pathways utilize second messengers to ____.

Receptors for polar molecules are found ____, while receptors for nonpolar molecules are located ____.

Quorum sensing ____.

Why are steroid hormones bound to carrier proteins in the blood?

Estrogen receptor (ER) α typically ____, while ERβ typically ____.

In order for a target cell to receive a signal, it must possess a ____ specific to the signaling molecule.

An active phosphatase adds phosphate groups to other molecules.

Introduction to Biological Concepts and Research

Life, Chemistry, and Water

Biological Molecules: the Carbon Compounds of Life

Cells

Membranes and Transport

Energy, Enzymes, and Biological Reactions

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Division and Mitosis

Meiosis: the Cellular Basis of Sexual Reproduction

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Expression: From Dna to Protein

Regulation of Gene Expression

Bacterial and Viral Genetics

Dna Technology: Making and Using Genetically Altered Organisms, and Other Applications

Genomes and Proteomes

The Development of Evolutionary Thought

Microevolution: Genetic Changes Within Populations

Speciation

Paleobiology and Macroevolution

Systematic Biology: Phylogeny and Classification

The Origin of Life

Prokaryotes and Viruses

Protists

Seedless Plants

Seed Plants

Fungi

Animal Phylogeny, Acoelomates, and Protostomes

Deuterostomes: Vertebrates and Their Closest Relatives

The Plant Body

Transport in Plants

Plant Nutrition

Reproduction and Development in Flowering Plants

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Information Flow and the Neuron

Nervous Systems

Sensory Systems

The Endocrine System

Muscles, Bones, and Body Movements

The Circulatory System

Defenses Against Disease

Gas Exchange: the Respiratory System

Digestive Systems and Animal Nutrition

Regulating the Internal Environment: Osmoregulation, Excretion, and Thermoregulation

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

Filters

Receptors for polar molecules are found , while receptors for nonpolar molecules are located .

Estrogen receptor (ER) α typically , while ERβ typically .