j. Lecture 9 Slide Deck (February 3rd) Flashcards
a) What does GPCR stand for?
b) what is it?
a) G Protien-coupled receptors
b) receptors that activate G proteins when a ligand binds to it
ANS the following wrt hydrophobic hormones
a) where are the receptors found
b) does this involve signal transduction pathways? Why?
c) does this lead to long-term or short-term effects? How do you know?
a) in the cytoplasm or nucleus
b) no, bc it can influence what happens in the cell directly
c) long-term b/c it acts a transcription factor that can directly influence the transcription of a certain gene
ANS the following wrt hydrophilic hormones
a) where are the receptors found
b) does this involve signal transduction pathways? Why?
c) does this lead to long-term or short-term effects? How do you know?
a) on the membrane
b) yes, b/c it is unable to directly influence what is happening in the cell thus it needs to use other intracellular proteins
c) short-term, b/c its signal is cascaded and amplified but very short
T or F - both effector enzymes and kinases can be plasma membrane receptors
T
What are the two kinds of changes that occur after;
a) a hydrophobic hormone binds to its receptor?
b) a hydrophilic hormone binds to its receptor?
a) changes in gene expression
b) changes in cellular metabolism
Describe signal transduction
a process of sensing external stimuli and conveying the info to intracellular targets (extracellular signal -> intracellular response)
Dexamethasone is an example of a
a) glucocorticoid receptor
b) hydrophobic hormone
c) hydrophilic hormone
e) chaperone protein
b
Describe the steps involved in hydrophilic signaling including the terms; ligand, plasma membrane receptor, conformational change, signal transduction proteins, second messengers, effector proteins, negative feedback
- the ligand binds to its plasma membrane receptor
- the receptors change conformation activating it
- the receptor activates a cascade of signal transduction proteins and second messengers
- the effector proteins get activated leading to a response
- A negative feedback occurs causing the removal of the ligand
T or F - 1 membrane receptors can bind to many different types of ligands depending on which one is available
F - 1 type of receptor for 1 type of ligand
What are the three types of hydrophilic signaling molecules (ligands). Match them to the following
a) Glucagon
b) insulin
c) adrenaline
a) short peptides
b) long proteins
c) small organic molecules
Describe the 4 types of extracellular signaling.
- endocrine = secreting cell (SC) sends signaling hormones to the target cell (TC) via BV
- paracrine = SC sends signaling hormones to adjacent TC
- autocrine = SC sends signaling hormones to self externally (SC=TC)
- Signaling by plasma membrane-attached proteins = SC directly attaches its mem to the TCs mem via proteins and sends a signal that way
This image is demonstrating which of the following
a) endocrine signaling
b) paracrine signaling
c) autocrine signaling
d) signaling by plasma membrane-attached proteins
a
This image is demonstrating which of the following
a) endocrine signaling
b) paracrine signaling
c) autocrine signaling
d) signaling by plasma membrane-attached proteins
b
This image is demonstrating which of the following
a) endocrine signaling
b) paracrine signaling
c) autocrine signaling
d) signaling by plasma membrane-attached proteins
c
This image is demonstrating which of the following
a) endocrine signaling
b) paracrine signaling
c) autocrine signaling
d) signaling by plasma membrane-attached proteins
d
Describe the following enzymes
a) kinases
b) phosphatases
a) an enzyme that phosphorylates target molecules by adding a phosphate gr
b) an enzyme that dephosphorylates a target molecule by removing a phosphate gr
What does phosphorylation do?
it causes a conformational change due to adding a phosphate gr
T or F - phosphorylating a target protein will always result in its activation
F - it can sometimes result in its inhibition
______ activates _______
a) G-proteins, GPCR
b) GPCR, G-proteins
c) GPCR, hydrophilic homornes
d) hydrophobic hormones, GPCR
b
a) what is the fxn of GTPase
b) what is the fxn of GAPs
c) does this result in activation or inactivation
d) where are these located wrt the G-protein
a) it hydrolyses GTP to GDP
b) GTPase-accelerating protein = proteins that speed up the GTPase process
c) inactivation
d) w/in the G-proteins themselves
a) What does GEF stand for?
b) What is the fxn of GEF?
c) does this result in activation or inactivation?
d) where are these located wrt the G-protein
a) guanine nucleotide exchange factor
b) to swap the GDP w/in a G-protein w/ a GTP
c) activation
d) done by the a protein that binds to the G-protein
Match the following
a) GEF
b) GAP
1. activation
2. inactivation
a) 1
b) 2
Inactive G-proteins are capable of interacting w/ ______. While active G-proteins are capable of interacting w/ __________.
a) upstream effector proteins, downstream activators
b) downstream effector proteins, upstream activators
c) downstream activators, upstream effector proteins
d) upstream activators, downstream effector proteins
d
What are the types of kinases?
- tyrosine
- serine
