WorksheetsSignal Transduction SSCY 3343 2025/2026 2
Total questions: 15
Worksheet time: 9mins
Name THREE (3) groups of possible ligand molecules that can induce signal transduction
cytokines
hormones
WBC
growth factors
What is the major function of an intracellular receptor?
relaying singal into the intracellular region of a cell
regulators of mRNA synthesis to mediate gene expression
allows the binding of an extracellular signal
Which of these are hydrophilic secondary messengers? I) DAG & IP3 II) cAMP & Ca2+ III)NO IV) IP3 & cGMP
I and II
III and IV
II and III
II and IV
How can the function of cAMP be turned off?
downregulation of IP3
phosphodiesterase
hydrolysis of GTP to GDP
Hydrolysis of cGMP
What is the similarity between PLC, AC & GC
1st messengers
effector proteins
2nd messengers
protein kinases
Which of these is/are correct about Ca2+ signal transduction
activation of of the Calmodulin pathway
relaxation of smooth muscle
2nd messenger
contraction of smooth muscle
What is responsible for the production of NO?
Calmodulin
NO synthase
Ca2+ influx
L-Arginine+O2
Which of the following is NOT a task of receptors?
Receiving ligand
Storing energy
Transferring a signal
A pharmaceutical company is developing a new drug. The drug is an antagonist for pain receptors, and blocks the feeling of pain. The drug works, but the company is concerned that the drug’s affinity for the receptor is too high. Why is this a concern
A high affinity means people will only need to buy one dose
The drug may stay attached to the receptor
It is not a concern
Patients may not be able to feel any sort of pain at all
What signaling component do these characteristics refer to?
-dimer ligand binding for activation
-large extracellular and intracellular domains
- activation of multiple cellular responses
GPCR
Enzyme-linked receptor
PIP2
Intracellular receptor
Activation of PLC would consequently.....
cleave PIP2
activate PKA
activate PKC
leads to opening of ligand gated ion channel-release Ca2+
Smooth muscle relaxation results in...
Rise in Ca2+
Downregulation of IP3
Upregulation of cGMP
PKA activation
GPCR →A→Adenylyl Cyclase→B→C→CREB TF→transcription of target genes. Name the components/activity represented by A, B and C in its ACITVE signaling pathway form.
A: GDP bound Gα-subunit
B: cAMP
C:PKG
A: GTP bound Gα-subunit
B: cGMP
C:PKA
A: GTP bound Gα-subunit
B: cAMP
C:PKA
A: GTP bound Gα-subunit
B: cAMP
C:PKC
NO is synthesized in the_____ while cGMP is synthesized in the _____when NO binds to soluble Guanylyl Cyclase
Smooth muscle cell
Epithelial cells
Endothelial cell
Smooth muscle cell
Epithelial cell
Endothelial cell
Endoplasmic reticulum
Smooth muscle cell
Allosteric binding site on ligand gated ion channels refers to.......
binding of ligand to its receptor
binding of ligand at the channel opening
Binding of ligand away from the channel
Binding of ligand to an effector protein
