Question 1

How is the stimulus by light terminated so that the initial state is restored?

Accepted Answer

A)  Activated rhodopsin is blocked from activating transducin when metarhodopsin II (R*) is phosphorylated and the inhibitor arrestin binds the R*. 
B)  The level of cGMP is raised to reopen the gated ion channels. 
C)  The GTP bound to the G protein is hydrolyzed, allowing the transducin and the phosphodiesterase to return to their original states. 
D)  All of the above. 
E)  None of the answers is correct. 
A)  Activated rhodopsin is blocked from activating transducin when metarhodopsin II (R*) is phosphorylated and the inhibitor arrestin binds the R*. 
B)  The level of cGMP is raised to reopen the gated ion channels. 
C)  The GTP bound to the G protein is hydrolyzed, allowing the transducin and the phosphodiesterase to return to their original states. 
D)  All of the above. 
E)  None of the answers is correct.

Question 2

What clues indicate that protein receptors are important in detection of smells?

Accepted Answer

Specific anosmias (the inability to dete

Question 3

What evidence is there that sweet receptors are heterodimeric?

Accepted Answer

Studies in knockout mice indic

Question 4

How were genes identified for bitter tastants?

Accepted Answer

A)  A specific taste was genetically linked to a chromosome region and the DNA sequence examined for a sequence similar to 7TM receptors. 
B)  Knockout mice were used to determine the exact sequence. 
C)  A hybridization analysis of all genes expressed in taste buds with 7TM probes was obtained. 
D)  Protein purification and characterization of a family of proteins were conducted. 
E)  Taste tests were conducted with humans deficient in 7TM receptors. 
A)  A specific taste was genetically linked to a chromosome region and the DNA sequence examined for a sequence similar to 7TM receptors. 
B)  Knockout mice were used to determine the exact sequence. 
C)  A hybridization analysis of all genes expressed in taste buds with 7TM probes was obtained. 
D)  Protein purification and characterization of a family of proteins were conducted. 
E)  Taste tests were conducted with humans deficient in 7TM receptors.

Question 5

What protein has been identified as a potential transduction channel for detecting sound from fruit fly experiments?

Accepted Answer

A)  ankyrin repeats 
B)  helix-turn-helix protein 
C)  NompC (No mechanoreceptor potential) 
D)  hear2 
E)  bundl 
A)  ankyrin repeats 
B)  helix-turn-helix protein 
C)  NompC (No mechanoreceptor potential) 
D)  hear2 
E)  bundl

Question 6

The sense of vision is due to the absorption of light by _________________cells in the eye.

Accepted Answer

photorecep

Question 7

Which of the following is a tastant category?

Accepted Answer

A)  acidic 
B)  oily 
C)  fruity 
D)  creamy 
E)  umami 
A)  acidic 
B)  oily 
C)  fruity 
D)  creamy 
E)  umami

Question 8

The _________________ family of receptors is involved in odor and some taste sensations.

Accepted Answer

The answer of The _________________ family of receptors is involved...

Question 9

Which photoreceptors are most closely related in humans?

Accepted Answer

A)  green and blue 
B)  green and red 
C)  red and rhodopsin 
D)  rhodopsin and green 
E)  blue and red 
A)  green and blue 
B)  green and red 
C)  red and rhodopsin 
D)  rhodopsin and green 
E)  blue and red

Question 10

How do taste and odor detection vary?

Accepted Answer

Each neuron detecting odor expresses one

Question 11

How is expression of OR proteins controlled?

Accepted Answer

A)  Expression is controlled by stimuli from the environment. 
B)  Expression is activated by feedback mechanisms from the olfactory sensory system. 
C)  Each olfactory neuron produces only one OR receptor protein. 
D)  All neurons produce the OR proteins, as there is no reason to increase or decrease expression. 
E)  Each neuron produces a subset of related OR proteins, under control of a common stimulus. 
A)  Expression is controlled by stimuli from the environment. 
B)  Expression is activated by feedback mechanisms from the olfactory sensory system. 
C)  Each olfactory neuron produces only one OR receptor protein. 
D)  All neurons produce the OR proteins, as there is no reason to increase or decrease expression. 
E)  Each neuron produces a subset of related OR proteins, under control of a common stimulus.

Question 12

How were initial matches made to link specific odors to receptors?

Accepted Answer

A)  overexpression of genes in rats 
B)  binding of odors to receptor molecules 
C)  studying the effect of odors on rats 
D)  sequence comparison to other known proteins 
E)  isolation and characterization of OR proteins 
A)  overexpression of genes in rats 
B)  binding of odors to receptor molecules 
C)  studying the effect of odors on rats 
D)  sequence comparison to other known proteins 
E)  isolation and characterization of OR proteins

Question 13

In which sensory systems do 7TM receptors play a role?

Accepted Answer

A)  hearing 
B)  olfaction 
C)  vision 
D)  hearing and olfaction 
E)  olfaction and vision 
A)  hearing 
B)  olfaction 
C)  vision 
D)  hearing and olfaction 
E)  olfaction and vision

Question 14

What characteristics were sought in cDNA libraries to identify the G proteins involved in olfactory systems?

Accepted Answer

The cDNAs sought had to be exp

Question 15

What structural features are important in the light-detecting function of the chromophore 11-cis-retinal?

Accepted Answer

A)  It is a polyene with alternating single and double bonds forming an unsaturated electron network. 
B)  It is easily ionized to carry a charge. 
C)  It has several linked cyclic rings. 
D)  It is very water soluble. 
E)  It is highly colored. 
A)  It is a polyene with alternating single and double bonds forming an unsaturated electron network. 
B)  It is easily ionized to carry a charge. 
C)  It has several linked cyclic rings. 
D)  It is very water soluble. 
E)  It is highly colored.

Question 16

Which ions signal a sour taste as they pass through ion channels?

Accepted Answer

A)  hydrogen 
B)  sodium 
C)  potassium 
D)  chloride 
E)  ammonium 
A)  hydrogen 
B)  sodium 
C)  potassium 
D)  chloride 
E)  ammonium

Question 17

Because the major clue to the mechanism of hearing is speed,sounds are detected through

Accepted Answer

A)  7TM receptors. 
B)  amiloride-sensitive ion channels. 
C)  chemical receptors. 
D)  mechanosensory ion channels. 
E)  None of the answers is correct. 
A)  7TM receptors. 
B)  amiloride-sensitive ion channels. 
C)  chemical receptors. 
D)  mechanosensory ion channels. 
E)  None of the answers is correct.

Question 18

What visual pigment is found in rods?

Accepted Answer

A)  chlorophyll 
B)  phycocyanin 
C)  carotene 
D)  rhodopsin 
E)  anthrocyanin 
A)  chlorophyll 
B)  phycocyanin 
C)  carotene 
D)  rhodopsin 
E)  anthrocyanin

Question 19

How is olfactory detection maximized?

Accepted Answer

Most receptors can detect more than one

Question 20

Capsaicin is a chemical found in _______________.

Accepted Answer

The answer of Capsaicin is a chemical found in _______________....

Exam 33: Sensory Systems

How is the stimulus by light terminated so that the initial state is restored?

What clues indicate that protein receptors are important in detection of smells?

What evidence is there that sweet receptors are heterodimeric?

How were genes identified for bitter tastants?

What protein has been identified as a potential transduction channel for detecting sound from fruit fly experiments?

The sense of vision is due to the absorption of light by _________________cells in the eye.

Which of the following is a tastant category?

The _________________ family of receptors is involved in odor and some taste sensations.

Which photoreceptors are most closely related in humans?

How do taste and odor detection vary?

How is expression of OR proteins controlled?

How were initial matches made to link specific odors to receptors?

In which sensory systems do 7TM receptors play a role?

What characteristics were sought in cDNA libraries to identify the G proteins involved in olfactory systems?

What structural features are important in the light-detecting function of the chromophore 11-cis-retinal?

Which ions signal a sour taste as they pass through ion channels?

Because the major clue to the mechanism of hearing is speed,sounds are detected through

What visual pigment is found in rods?

How is olfactory detection maximized?

Capsaicin is a chemical found in _______________.

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

Signal-Transduction Pathways

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

The Immune System

Molecular Motors

Drug Development

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