Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacy Year 2 TBL 1 > Receptors > Flashcards

Receptors Flashcards

1
Q

Describe signal transduction

A 
Receptor	proteins	bind	“signals”	
i.e.	drugs		&	endogenous	ligands	
with	high	affinity		
Conforma)onal	changes in	the	
structure	of	the	receptor	protein	
then	convert	the	chemical	signal	
into	one	or	more	intra-cellular
signals.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

3 types of naturally occurring chemical messengers

A

Hormones
Neurotransmitters
Local chemical mediators
Not natural - clinically useful drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Receptors are embedded where?

A

Protein membrane/bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

3 families of plasma membrane receptors

A

G protein coupled - associated with GTP
Tyrosine kinase receptors- property of phosphorlyating tyrosine residues
Ligand gated ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Receptor tyrosine kinases are activated by what?

A

cytokines, peptide hormones, growth factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do tyrosine kinase proteins do/regulate?

A

Regulate cell proliferation, differentiation and function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are implicated as oncogenes?

anti cancer drug targets

A

Protein tyrosine kinases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the basic structure of RTK (receptor tyrosine kinase)

A

3 essential components

1) ligand binding site (extracellular domain)
2) transmembrane domain (alpha helix)
3) Domain with tyrosine kinase activity (cytosolic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe RTK in absence of a bound ligand

A
  • generally monomeric

- poorly active kinases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe RTK when there is a bound ligand

A

Conformational change and a formation of a dimer receptor

Phosphorlyation of tyrosine residues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the EGF receptor in one word

epidermal growth factor

A

bivalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the insulin receptor

A

dimer of two identical units
disulphide bond linked
insulin binding activates the kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the process that occurs when insulin binds to its receptor

A

phosphorlyation of activation receptor
activates insulin receptor tyrosine kinase
phosphorylated sites then act as docking sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

IRS-1 binds what?

A

1) phosphotyrosine
2) and IRS-1 is phosphorylated by the receptor
3) PI-3 binds phosphorylated IRS-1… PIP2 phosphorlyated to PIP3
4) PIP3 binds PDK1 which is a kinase. Phosphorylation of Atk1 occurs
5) Movement of GLUT4 to cellular membrane occurs. transport of glucose into cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Kinase activity is implicated in which diseases?

A

rheumatoid arthiritis
asthma
neurological disorders
cancers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can the modulation of kinase activity be achieved?

A

disrupt protein-protein interactions
inhibit phosphorylation activity (prevent ATP binding)
Downregulate kinase gene expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Tell me about a drug that works by blocking ligand binding

TK receptor

A

Bevacizumab binds to growth factors thus preventing their binding to receptors
This interferes with tumour blood vessel development
First line of treatment for colorectal cancers

18
Q

How does imatinib mesylate work? What is it used for?

A

Targets ATP binding

chronic myeloid leukaemia and acute lymphoblastic leukaemia

19
Q

How does Gefitinib work?

A

targets ATP binding to EGFR

EGFR is overexpressed in many solid tumours

20
Q

Ion channels can be controlled by…. (2)

A

Ligands - ligand-gated ion channels

membrane potentials - voltage gated ion channels

21
Q

Describe the general structure and gating of ion channels

A

5 protein subunits with receptor sites on 1 or more subunits
Ligand gated channel or lock/gating mechanism
receptor protein sensitive a chemical messenger
induced fit binding leads to conformational change which allows for ion passage

22
Q

Cationic channels are for which ions?

Give one example of an ion channel of this type

A

Na+, K+, Ca2+

nicotinic acetylcholine receptor (role in synapes)

23
Q

Anionic channels are for which ions?

Give one example of an ion channel of this type

A

Cl-
GABA and glycine gated Cl- channels
associated with many inhibitory synapses

24
Q

How do local anaesthics work?

hint: think about ion channels

A

block conductance of Na+ and reduce pain perception

25
Q

how do benzodiazipines work?

hint: think about ion channels

A

increase the availability of GABA to conduct Cl- across membranes
This drives the membrane potential away from its threshold of activation
this reduces communication between neurones and hence sedation

26
Q

Define receptor

A

a protein which acts as a sensing element of a cell, allowing cells to receive messages to one another

27
Q

Define agonist

A

mimic function of messenger by binding to receptor and causing normal response

28
Q

Define antagonist

A

Binds receptor but fails to produce a response. Acts as an inhibitor for other possible chemicals that may want to bind to the receptor

29
Q

Describe a G protein coupled receptor

A

Family of receptors associated with GTP binding proteins

The receptor has 7 transmembrane helices

30
Q

Give 4 examples of substances that activate G protein coupled receptors

A

GABA, acetylcholine, dopamine, noradrenaline

31
Q

Give 1 example/role of G protein receptors

A

beta-adrenergic receptor

target of beta blocker drugs such as propanolol, which is used to treat heart problems

32
Q

GPCR activates which 2nd messengers? (2)

A

cyclic AMP
The enzyme adenylate cyclase products cAMP which then activates a kinase

phospholipase C
this causes inositol phospholipid cleavage to produce IP3 and DAG

33
Q

What is the main clinical use for beta-adrenergic agonists?

A

ashtma
to relax the smooth muscle of the bronchi
e.g. salbutamol

34
Q

How does cholera mediate use G proteins to mediate its infection of the body?

A

toxin production which stabilises GTP bound form of the G protein subunit
continual activation of protein kinase A
opens Cl- channels
diarrhoea occurs as Cl- escapes into colon, water follows due to osmosis
watery stool

35
Q

epinephrine + beta-adrenergic receptor causes

A

energy store mobilisation

36
Q

insulin + insulin receptor causes

A

increased glucose uptake into cells

37
Q

epidermal growth factor + EGF receptor causes

A

expression of growth-promoting genes

38
Q

Intracellular receptors are also known as

A

nuclear transcription factors

nuclear hormone receptors

39
Q

Describe the basic structure of an intracellular receptor

A

single protein containing a ligand binding site at the C terminal and a binding region for DNA near the centre (zinc fingers)

40
Q

Drug targeting oestrogen receptors

A

Tamoxifen
works via competitive inhibition of oestrogen binding to the receptor
inhibits expression of oestrogen regulated genes
advanced breast cancer treatment and primary breast cancer treatment - FDA approved

Pharmacy Year 2 TBL 1 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions