Question 1

What is the difference between heterotrimeric G proteins and small G proteins?

Accepted Answer

Heterotrimeric G proteins are composed o

Question 2

The enzyme responsible for induction of the phosphoinositide cascade is

Accepted Answer

A)  phospholipase C. 
B)  phospholipase A. 
C)  C-dependent protein (CDP). 
D)  calmodulin. 
E)  None of the answers is correct. 
A)  phospholipase C. 
B)  phospholipase A. 
C)  C-dependent protein (CDP). 
D)  calmodulin. 
E)  None of the answers is correct.

Question 3

In addition to its range in concentration,what other property of calcium ion makes it a highly suitable messenger?

Accepted Answer

It can bind tightly to proteins because

Question 4

How does binding of epinephrine initiate cAMP production? Discuss briefly in terms of receptor structure and function.

Accepted Answer

Epinephrine binds to a 7TM receptor whic

Question 5

Describe two roles of phosphatidylinositol 4,5-bisphosphate (PIP2)in signal transduction.

Accepted Answer

1.PIP₂ is one of the signal molecules in

Question 6

Advantages of second messengers include

Accepted Answer

A)  the signal can be amplified by making many second messengers. 
B)  second messengers can freely diffuse to other sites within the cell. 
C)  a few common second messengers can be used in multiple signaling pathways. 
D)  All of the answers are correct. 
E)  A and C. 
A)  the signal can be amplified by making many second messengers. 
B)  second messengers can freely diffuse to other sites within the cell. 
C)  a few common second messengers can be used in multiple signaling pathways. 
D)  All of the answers are correct. 
E)  A and C.

Question 7

What enzyme becomes active when bound to Ca2+ and diacylglycerol?

Accepted Answer

A)  calmodulin 
B)  protein kinase A 
C)  protein kinase C 
D)  phospholipase C 
E)  adenylate cyclase 
A)  calmodulin 
B)  protein kinase A 
C)  protein kinase C 
D)  phospholipase C 
E)  adenylate cyclase

Question 8

What are some of the common structural features of the receptors to which signal molecules bind?

Accepted Answer

The molecule must have a signal-binding

Question 9

Why is bound GTP considered a "clock"?

Accepted Answer

A)  It is always produced and degraded in specific time intervals. 
B)  It is regulated by energy. 
C)  The G$\alpha$ receptors have intrinsic GTPase activity, hydrolyzing GTP to GDP and Pi. 
D)  It spontaneously hydrolyzes in the binding site of G proteins. 
E)  None of the answers is correct. 
A)  It is always produced and degraded in specific time intervals. 
B)  It is regulated by energy. 
C)  The G$\alpha$ receptors have intrinsic GTPase activity, hydrolyzing GTP to GDP and Pi. 
D)  It spontaneously hydrolyzes in the binding site of G proteins. 
E)  None of the answers is correct.

Question 10

What is the relationship between monoclonal antibodies,breast cancer,and HER2?

Accepted Answer

HER2 is a membrane protein that is very

Exam 14: Signal-Transduction Pathways

What is the difference between heterotrimeric G proteins and small G proteins?

The enzyme responsible for induction of the phosphoinositide cascade is

In addition to its range in concentration,what other property of calcium ion makes it a highly suitable messenger?

How does binding of epinephrine initiate cAMP production? Discuss briefly in terms of receptor structure and function.

Describe two roles of phosphatidylinositol 4,5-bisphosphate (PIP2)in signal transduction.

Advantages of second messengers include

What enzyme becomes active when bound to Ca2+ and diacylglycerol?

What are some of the common structural features of the receptors to which signal molecules bind?

Why is bound GTP considered a "clock"?

What is the relationship between monoclonal antibodies,breast cancer,and HER2?

Biochemistry: An Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

Oxidative Phosphorylation

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, repair, and Recombination

RNA Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

Describe two roles of phosphatidylinositol 4,5-bisphosphate (PIP₂)in signal transduction.

What enzyme becomes active when bound to Ca²⁺ and diacylglycerol?