Brainscape's Knowledge GenomeTM

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


See full index

POM > Cell signalling > Flashcards

Cell signalling Flashcards

1
Q

Why do cells need to communicate?

A

Process information - sensory stimuli
Self preservation - fight or flight - spinal reflexes for sympathetic nervous system
Voluntary movement
Homeostasis - thermoregulation/glucose homeostasis

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

Hypoglycaemia is an example of?

A

Endocrine communication - leads to glycogen breakdown + gluconeogenesis
Glucagon secreted by a cells in pancreas ; glucagon travels out of pancreas in blood vessels and stimulates both processes within the liver

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

Endocrine signalling

A

When a hormone travels via blood from organ to another organ

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

Insulin

A

Another type of endocrine signalling ; acts on muscle/adipose tissue/liver

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

Adrenaline

A

Acts on trachea - endocrine signalling

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

Hyperglycaemia - mechanism of insulin can also be?

A

PARACRINE SIGNALLING - insulin secretion via b cells and acts on alpha cells next to it to inhibit glucagon secretion (as well as endocrine function in the liver)

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

Paracrine signalling?

A

Hormone acts on adjacent cells

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

Other examples of paracrine signalling

A

Nitric oxide produced by endothelial cellist blood vessels- vasodilation (reduces blood pressure)
Osteoblast activating factors produced by adjacent osteoblasts

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

Osteoblast

A

Cell which secretes the substance of bone

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

Signalling between membrane attached proteins

A

The pathogen is detected by an APC which digests the pathogen and expresses the MHC class II molecule on the surface ; circulating T-lymphocyte engages with MHC through TCR

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

Membrane attached proteins

A

Plasma membrane proteins on adjacent cells interact

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

Examples of membrane attached proteins

A

HIV gp120 glycoprotein with CD4 receptor on T lymphocytes
Bacterial cell wall components detection ; using receptors on heatopoietic cells

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

Autocrine signalling with T cell

A

Activated TCR will initiate a cascade of reactions within T cell and that will express IL-2 receptor on surface
T cell secrete IL-2 molecules which can now bind to IL-2 receptors on the same cell and those on adjacent cells (paracrine)

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

Examples of autocrine

A

Acetylcholine -> presynaptic M2 muscarinic receptors
Growth factors from tumour cells leading to mitogenesis

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

Neurotransmission mechanism

A

Propagation of action potential by VGSCs ; NA+ influx leads to membrane depolarisation and there is then a K+ efflux
AP opens ca2+ channel at presynaptic terminal ; ca2+ influx causes acetylcholine exocytosis
NT binds to receptors on post synaptic neurone
Activation of post synaptic receptor

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

Post synaptic cell

A

Can be muscle neurone whatever

17
Q

4 types of receptors

A

Ionotropic receptor - ligand binding causes ion permeable pore to open
G protein coupled receptor ; ligand binding activates intracellular G-protein
Enzyme linked receptor - ligand binding results in receptor clustering causing activation of internal enzymes
Intracellular receptor - membrane permeable ligand binds to receptor inside cell

18
Q

Iontropic receptors

A

Ligand binds to receptor protein and this changes conformation of channel protein ; pore now allows ions to move in and out of cell (respective to conc gradients)

19
Q

Ionotropic receptor example

A

Nicotinic Acetylcholine ; ligand is Ach ; located in the skeletal muscle and results in muscle conc

20
Q

GABA channels

A

Ion channels

21
Q

G-protein coupled receptors

A

Heterotrimeric G-protein ; alpha beta and gamma ; BETA AND GAMMA ALWAYS STICK TOGHETHER

22
Q

80% of drugs target them

A

G-protein coupled receptors

23
Q

Another word for a g-protein coupled receptor

A

Serpentine receptor

24
Q

Mechanism of action of G protein coupled receptor

A

7-TM receptor and heterotrimeric G-protein are inactive
Ligand binds and changes conformation of receptor
Unassociated G protein binds to the receptor and GDP is exchanged for GTP which allows beta and gamma to separate from alpha and GTP
Alpha and gtp/beta gamma bind to their target proteins
GTPase acts on alpha subunit causing GTP to go to GDP and alpha unit dissociates from target protein to form the inactive heatertrimeric G protein

25
Q

How long does the receptor remain active for in a G protein coupled receptor?

A

Receptor remains active as long as ligand is bound and can activate other heterotrimeric G-proteins tooooo

26
Q

What is the target protein that is often targeted by the components of the heterotrimeric G protein?

A

Adenylyl cyclase

27
Q

Example of a G protein linked receptor that stimulates adenylyl cyclase?

A

b-andrenergic receptor (this is how adrenaline acts on the heart) ; it converts ATP to cAMP which activates your protein kinase

28
Q

G protein linked receptor that inhibits adenylyl cyclase

A

M2 muscarinic receptor (parasympathetic nervous system that is continuously keeping your heart rate down) ; this REDUCES levels of protein kinase A

29
Q

Gs/Gi

A

Stimulatory/inhibitory G protein

30
Q

Gq protein linked receptor

A

Phospholipase C is what GQ is linked to and this c causes an increase in calcium ; example is angiotensin receptor that causes vasoconstriction - so a common drug target is ACE inhibitors for hypertension

31
Q

Enzyme linked receptors

A

Ligand binding externally causes receptors to cluster internally which activates enzymes in the cytoplasm ; these enzymes phosphorylate the receptor (which moves receptors into a high energy state) ; signalling proteins are now bound to the cytoplasmic domain (receptors)

32
Q

Insulin receptor is also known as

A

CD220 antigen

33
Q

Classify insulin receptor?

A

Enzyme-linked receptor with the ligand being insulin and effect being glucose uptake

34
Q

ErbB receptors

A

The ligand is an epidermal growth factor/transforming growth factor which causes cell growth/proliferation

35
Q

Intracellular receptors Type 1 is

A

Cytoplasmic ; receptor in cytosol and associated with heat shock protein ; hsp dissociates and 2 hormone bound receptors form a homodimer which translocates to the nucleus to bind with dNA

36
Q

Intracellular receptor Type 2 is

A

Nuclear ; bind of hormone ligand to receptor in nucleus which now regulates transcription

37
Q

intracellular receptors - glucocorticoid

A

Ligand is cortisol/corticosterone and this decreases immune response and increases gluconeogenesis

38
Q

Intracellular receptors - thyroid hormone receptor

A

Thyroxine and triiodothyronine (T4 and T3) are ligands and the physiological response is growth and development

POM (12 decks)

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