Question 1

Steroid and thyroid hormones do not bind to membrane surface receptors because they ____.

Accepted Answer

A)  are small enough to pass directly through the membrane 
B)  are soluble in the lipid bilayer 
C)  pass through special membrane channels 
D)  are water-soluble 
E)  dissolve in the cholesterol present in cell membranes 
A)  are small enough to pass directly through the membrane 
B)  are soluble in the lipid bilayer 
C)  pass through special membrane channels 
D)  are water-soluble 
E)  dissolve in the cholesterol present in cell membranes

Question 2

Substance E is made in the pancreas, travels through the blood, and binds to a surface receptor on a target cell. After dimerization and autophosphorylation, the receptor activates a signaling protein. Substance E is therefore the ligand for ____.

Accepted Answer

A)  a receptor tyrosine kinase 
B)  a G-protein-coupled receptor 
C)  a hormone receptor 
D)  a ligand-gated ion channel 
E)  guanylyl cyclase 
A)  a receptor tyrosine kinase 
B)  a G-protein-coupled receptor 
C)  a hormone receptor 
D)  a ligand-gated ion channel 
E)  guanylyl cyclase

Question 3

Inactive G proteins are ____.

Accepted Answer

A)  bound to GMP 
B)  bound to GDP 
C)  bound to GTP 
D)  phosphorylated 
E)  unphosphorylated 
A)  bound to GMP 
B)  bound to GDP 
C)  bound to GTP 
D)  phosphorylated 
E)  unphosphorylated

Question 4

The protein kinase activity of the receptor tyrosine kinase (RTK) is located ____ region of the protein.

Accepted Answer

A)  on the extracellular 
B)  on the cytoplasmic 
C)  within the hydrophobic 
D)  in the nuclear 
E)  in the inactive 
A)  on the extracellular 
B)  on the cytoplasmic 
C)  within the hydrophobic 
D)  in the nuclear 
E)  in the inactive

Question 5

Neurotransmitters are molecules released by ____.

Accepted Answer

A)  gonads 
B)  polar hormones 
C)  peptide hormones 
D)  cells in the blood 
E)  neurons 
A)  gonads 
B)  polar hormones 
C)  peptide hormones 
D)  cells in the blood 
E)  neurons

Question 6

Hormone-independent steroid hormone receptor activation is an example of ____.

Accepted Answer

A)  allosteric activation 
B)  gene regulation 
C)  receptor integration 
D)  protein mutation 
E)  cross-talk 
A)  allosteric activation 
B)  gene regulation 
C)  receptor integration 
D)  protein mutation 
E)  cross-talk

Question 7

Many of the different types of GPCRs in humans function to ____.

Accepted Answer

A)  distinguish different volatile molecules for odor recognition 
B)  regulate metabolism by sensing and responding to changes in glucose levels 
C)  regulate liver function by responding to different macromolecules 
D)  aid in memory by binding to neurotransmitters in the amygdala 
E)  trigger the fight of flight response by binding to hormones in the hypothalamus 
A)  distinguish different volatile molecules for odor recognition 
B)  regulate metabolism by sensing and responding to changes in glucose levels 
C)  regulate liver function by responding to different macromolecules 
D)  aid in memory by binding to neurotransmitters in the amygdala 
E)  trigger the fight of flight response by binding to hormones in the hypothalamus

Question 8

Structurally similar RTKs have been found in all multicellular animals, suggesting that ____.

Accepted Answer

A)  RTK genes are resistant to mutation 
B)  RTKs evolved relatively early in the history of animals 
C)  RTKs evolved from G proteins 
D)  RTKs are not involved in vital processes in animals 
E)  RTKs have evolved independently of each other in animals 
A)  RTK genes are resistant to mutation 
B)  RTKs evolved relatively early in the history of animals 
C)  RTKs evolved from G proteins 
D)  RTKs are not involved in vital processes in animals 
E)  RTKs have evolved independently of each other in animals

Question 9

Which molecule is a common second messenger?

Accepted Answer

A)  cGTP 
B)  cATP 
C)  PIP2 
D)  diacylglycerol 
E)  Ras 
A)  cGTP 
B)  cATP 
C)  PIP2 
D)  diacylglycerol 
E)  Ras

Question 10

The system of communication between cells through signaling pathways is called homeostasis.

Accepted Answer

A) True 
 B)False

Question 11

A neuron synthesizes and secretes substance D, which binds to a receptor on the neuron cell membrane, triggering an influx of calcium. Substance D therefore is a ligand for a ____.

Accepted Answer

A)  a receptor tyrosine kinase 
B)  a G-protein-coupled receptor 
C)  a hormone receptor 
D)  a ligand-gated ion channel 
E)  guanylyl cyclase 
A)  a receptor tyrosine kinase 
B)  a G-protein-coupled receptor 
C)  a hormone receptor 
D)  a ligand-gated ion channel 
E)  guanylyl cyclase

Question 12

Nonpolar signaling molecules enter the cell by ____.

Accepted Answer

A)  facilitated diffusion 
B)  simple diffusion 
C)  osmosis 
D)  active transport 
E)  receptor-mediated endocytosis 
A)  facilitated diffusion 
B)  simple diffusion 
C)  osmosis 
D)  active transport 
E)  receptor-mediated endocytosis

Question 13

How many transmembrane domains are present in a G-protein-coupled receptor?

Accepted Answer

A)  one 
B)  three 
C)  five 
D)  seven 
E)  nine 
A)  one 
B)  three 
C)  five 
D)  seven 
E)  nine

Question 14

Which cellular response follows activation of a ligand-gated ion channel?

Accepted Answer

A)  direct regulation of gene expression 
B)  generation of an electrical signal 
C)  activation of a phosphorylation cascade 
D)  activation of a second messenger pathway 
E)  direct activation of a kinase 
A)  direct regulation of gene expression 
B)  generation of an electrical signal 
C)  activation of a phosphorylation cascade 
D)  activation of a second messenger pathway 
E)  direct activation of a kinase

Question 15

G proteins are inactivated when ____.

Accepted Answer

A)  GDP is converted to GTP 
B)  GTP is converted to GDP 
C)  the G protein rebinds the receptor 
D)  the G protein is released from the receptor 
E)  the receptor is broken down 
A)  GDP is converted to GTP 
B)  GTP is converted to GDP 
C)  the G protein rebinds the receptor 
D)  the G protein is released from the receptor 
E)  the receptor is broken down

Question 16

In plants, the IP3/DAG pathways control the organism's responses to water loss and changes in light intensity.

Accepted Answer

A) True 
 B)False

Question 17

NO can only function as a paracrine regulator because____.

Accepted Answer

A)  it is hydrophilic and cannot travel free in the blood 
B)  it is hydrophobic and cannot travel free in the blood 
C)  it is rapidly converted into nitrates and nitrites 
D)  its receptors are rapidly turned over 
E)  its receptors are immediately internalized when the ligand binds 
A)  it is hydrophilic and cannot travel free in the blood 
B)  it is hydrophobic and cannot travel free in the blood 
C)  it is rapidly converted into nitrates and nitrites 
D)  its receptors are rapidly turned over 
E)  its receptors are immediately internalized when the ligand binds

Question 18

Inactive Ras is bound to receptor tyrosine kinases by ____.

Accepted Answer

A)  G proteins 
B)  adapter proteins 
C)  phosphate bonds 
D)  peptide tethers 
E)  GDP 
A)  G proteins 
B)  adapter proteins 
C)  phosphate bonds 
D)  peptide tethers 
E)  GDP

Question 19

Substance B is synthesized in neurons, travels through gap junctions, and triggers the transduction of an electrochemical signal. 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 20

Activated G proteins ____.

Accepted Answer

A)  trigger endocytosis of the G-protein-coupled receptor 
B)  bind to second messengers 
C)  separate into two parts 
D)  activate a kinase 
E)  inhibit guanylyl cyclase 
A)  trigger endocytosis of the G-protein-coupled receptor 
B)  bind to second messengers 
C)  separate into two parts 
D)  activate a kinase 
E)  inhibit guanylyl cyclase

Exam 9: Cell Communication

Steroid and thyroid hormones do not bind to membrane surface receptors because they ____.

Substance E is made in the pancreas, travels through the blood, and binds to a surface receptor on a target cell. After dimerization and autophosphorylation, the receptor activates a signaling protein. Substance E is therefore the ligand for ____.

Inactive G proteins are ____.

The protein kinase activity of the receptor tyrosine kinase (RTK) is located ____ region of the protein.

Neurotransmitters are molecules released by ____.

Hormone-independent steroid hormone receptor activation is an example of ____.

Many of the different types of GPCRs in humans function to ____.

Structurally similar RTKs have been found in all multicellular animals, suggesting that ____.

Which molecule is a common second messenger?

The system of communication between cells through signaling pathways is called homeostasis.

A neuron synthesizes and secretes substance D, which binds to a receptor on the neuron cell membrane, triggering an influx of calcium. Substance D therefore is a ligand for a ____.

Nonpolar signaling molecules enter the cell by ____.

How many transmembrane domains are present in a G-protein-coupled receptor?

Which cellular response follows activation of a ligand-gated ion channel?

G proteins are inactivated when ____.

In plants, the IP3/DAG pathways control the organism's responses to water loss and changes in light intensity.

NO can only function as a paracrine regulator because____.

Inactive Ras is bound to receptor tyrosine kinases by ____.

Substance B is synthesized in neurons, travels through gap junctions, and triggers the transduction of an electrochemical signal. This is an example of ____.

Activated G proteins ____.

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

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In plants, the IP₃/DAG pathways control the organism's responses to water loss and changes in light intensity.