GabbieMichael's UMich Bio 272 Exam 3
Review: Blue Key Concepts Questions
and Answers
Large and hydrophilic signals bind to - Correct Answers -cell-surface receptors
Small, hydrophobic signal molecules bind to - Correct Answers -intracellular receptors
Small, hydrophobic signal molecule examples - Correct Answers -hormones; can diffuse
across the plasma membrane
Hormones - Correct Answers -small, hydrophobic; diffuse through plasma membrane
Hormones bind to ? - Correct Answers -intracellular receptor proteins = nuclear receptor
superfamily
Hormone binding alters the ability of the nuclear receptor superfamily proteins to ? -
Correct Answers -regulate transcription of specific genes
When are nuclear receptors present in an inactive form? - Correct Answers -in
unstimulated cells (without any signals)
When hormone (cortisol) binds, the nuclear receptor undergoes a ? - Correct Answers -
conformational change that actives the nuclear receptor
What does the conformational change of the nuclear receptor reveal? - Correct Answers
-a nuclear localization signal (NLS)
Activated nuclear receptors are ? - Correct Answers -transcription factors
What do activated nuclear receptors do? - Correct Answers -They are transcription
factors and bind to specific DNA regulatory sites to promote/inhibit the transcription of
specific target genes
Nuclear receptor proteins act as both the ? - Correct Answers -receptor and effector
protein
, Intracellular signaling pathway with a large, hydrophilic signal molecule: - Correct
Answers -extracellular signal
receptor
intracellular signaling proteins and "second messengers"
effector proteins
Molecular switch - Correct Answers -When signaled, these proteins switch from one
conformation to another conformation until another process turns them off
Molecular switch examples we learned about ? - Correct Answers -Signaling by protein
phosphorylation,
signaling by GTP-binding proteins
What does signaling by protein phosphorylation include? - Correct Answers
-serine/threonine kinases and tyrosine kinases
What does signaling by GTP-binding proteins include? - Correct Answers -large trimeric
GTPases (~300 amino acids) & small monomeric GTPases (~170 amino acids)
Three main classes of cell-surface receptors - Correct Answers -Ion-channel-coupled
receptors,
G-protein-coupled receptors,
Enzyme-coupled receptors
Many hormones and neurotransmitters signal through ? - Correct Answers -GPCRs;
our senses of sight and smell work through GPCRs
GPCRs - Correct Answers -are the largest family of cell-surface receptors,
have seven transmembrane alpha helices,
bind to trimeric G proteins
G proteins - Correct Answers -called heterotrimeric because they're made up of 3
different subunits: alpha, beta, gamma,
alpha and gamma have a covalently attached lipid molecule that attaches to the plasma
membrane,
beta and gamma function as a unit,
only the alpha subunit has GTPase activity
When GPCR is activated by ligand binding, what happens? - Correct Answers -it
undergoes a conformational change, allowing it to activate a G protein
The activated GPCR acts like a ? - Correct Answers -GEF - it induces the alpha subunit
of the trimeric G protein to release GDP, which is exchanged for GTP
GTP binding induces a conformational change in the ___ subunit - Correct Answers -
alpha
Review: Blue Key Concepts Questions
and Answers
Large and hydrophilic signals bind to - Correct Answers -cell-surface receptors
Small, hydrophobic signal molecules bind to - Correct Answers -intracellular receptors
Small, hydrophobic signal molecule examples - Correct Answers -hormones; can diffuse
across the plasma membrane
Hormones - Correct Answers -small, hydrophobic; diffuse through plasma membrane
Hormones bind to ? - Correct Answers -intracellular receptor proteins = nuclear receptor
superfamily
Hormone binding alters the ability of the nuclear receptor superfamily proteins to ? -
Correct Answers -regulate transcription of specific genes
When are nuclear receptors present in an inactive form? - Correct Answers -in
unstimulated cells (without any signals)
When hormone (cortisol) binds, the nuclear receptor undergoes a ? - Correct Answers -
conformational change that actives the nuclear receptor
What does the conformational change of the nuclear receptor reveal? - Correct Answers
-a nuclear localization signal (NLS)
Activated nuclear receptors are ? - Correct Answers -transcription factors
What do activated nuclear receptors do? - Correct Answers -They are transcription
factors and bind to specific DNA regulatory sites to promote/inhibit the transcription of
specific target genes
Nuclear receptor proteins act as both the ? - Correct Answers -receptor and effector
protein
, Intracellular signaling pathway with a large, hydrophilic signal molecule: - Correct
Answers -extracellular signal
receptor
intracellular signaling proteins and "second messengers"
effector proteins
Molecular switch - Correct Answers -When signaled, these proteins switch from one
conformation to another conformation until another process turns them off
Molecular switch examples we learned about ? - Correct Answers -Signaling by protein
phosphorylation,
signaling by GTP-binding proteins
What does signaling by protein phosphorylation include? - Correct Answers
-serine/threonine kinases and tyrosine kinases
What does signaling by GTP-binding proteins include? - Correct Answers -large trimeric
GTPases (~300 amino acids) & small monomeric GTPases (~170 amino acids)
Three main classes of cell-surface receptors - Correct Answers -Ion-channel-coupled
receptors,
G-protein-coupled receptors,
Enzyme-coupled receptors
Many hormones and neurotransmitters signal through ? - Correct Answers -GPCRs;
our senses of sight and smell work through GPCRs
GPCRs - Correct Answers -are the largest family of cell-surface receptors,
have seven transmembrane alpha helices,
bind to trimeric G proteins
G proteins - Correct Answers -called heterotrimeric because they're made up of 3
different subunits: alpha, beta, gamma,
alpha and gamma have a covalently attached lipid molecule that attaches to the plasma
membrane,
beta and gamma function as a unit,
only the alpha subunit has GTPase activity
When GPCR is activated by ligand binding, what happens? - Correct Answers -it
undergoes a conformational change, allowing it to activate a G protein
The activated GPCR acts like a ? - Correct Answers -GEF - it induces the alpha subunit
of the trimeric G protein to release GDP, which is exchanged for GTP
GTP binding induces a conformational change in the ___ subunit - Correct Answers -
alpha
