Question 1

Which of the following statements is true of signal molecules?

Accepted Answer

A)  When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules. 
B)  In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form IP₃ and calcium. 
C)  In most cases, signal molecules interact with the cell at the plasma membrane, enter the cell, and eventually enter the nucleus. 
D)  Protein kinase A activation is one possible result of signal molecules binding to G protein-coupled receptors. 
A)  When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules. 
B)  In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form IP₃ and calcium. 
C)  In most cases, signal molecules interact with the cell at the plasma membrane, enter the cell, and eventually enter the nucleus. 
D)  Protein kinase A activation is one possible result of signal molecules binding to G protein-coupled receptors.

Question 2

Protein phosphorylation is commonly involved with all of the following except

Accepted Answer

A)  activation of receptor tyrosine kinases. 
B)  activation of protein kinase molecules. 
C)  activation of G protein-coupled receptors. 
D)  regulation of transcription by signaling molecules. 
A)  activation of receptor tyrosine kinases. 
B)  activation of protein kinase molecules. 
C)  activation of G protein-coupled receptors. 
D)  regulation of transcription by signaling molecules.

Question 3

What role do phosphatases play in signal transduction pathways?

Accepted Answer

A)  They transfer a phosphate group from one protein in the pathway to the next molecule in the series. 
B)  They activate protein kinases by phosphorylation. 
C)  They amplify the second messenger cAMP. 
D)  They inactivate protein kinases to turn off signal transduction. 
A)  They transfer a phosphate group from one protein in the pathway to the next molecule in the series. 
B)  They activate protein kinases by phosphorylation. 
C)  They amplify the second messenger cAMP. 
D)  They inactivate protein kinases to turn off signal transduction.

Question 4

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following?

Accepted Answer

A)  increases glycogen phosphorylase activity in liver cells 
B)  activates adenylyl cyclase in liver cells 
C)  stimulates G protein activity in liver cells 
D)  increases phosphodiesterase activity in liver cells 
A)  increases glycogen phosphorylase activity in liver cells 
B)  activates adenylyl cyclase in liver cells 
C)  stimulates G protein activity in liver cells 
D)  increases phosphodiesterase activity in liver cells

Question 5

Apoptosis involves all but which of the following?

Accepted Answer

A)  fragmentation of the DNA 
B)  cell-signaling pathways 
C)  lysis of the cell 
D)  digestion of cellular contents by scavenger cells 
A)  fragmentation of the DNA 
B)  cell-signaling pathways 
C)  lysis of the cell 
D)  digestion of cellular contents by scavenger cells

Exam 11: Cell Communication

Which of the following statements is true of signal molecules?

Protein phosphorylation is commonly involved with all of the following except

What role do phosphatases play in signal transduction pathways?

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following?

Apoptosis involves all but which of the following?

Evolution, the Themes of Biology, and Scientific Inquiry

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Vascular Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

Filters