Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

YEAR 2 S1 BIOCHEM > Ian receptors and cell signalling > Flashcards

Ian receptors and cell signalling Flashcards

(42 cards)

Start Studying
1
Q

survival signals are generated by what what type of cell signalling?

A

cell cell contact

- esp with ECM and through adherence junctions

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

grow and divide signals are generated by what what type of cell signalling?
what are exceptions?

A
  • tends to be PARACRINE

- exceptions are Growth Hormone, Oestrogen and Testosterone

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

differentiate signals are generated by what what type of cell signalling?

A
  • local progenitor cells are the ones that have the abilityt to still divide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

apoptosis signals are generated by what what type of cell signalling?

A
  • extrinsic or intrinsic pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe contact dependent signalling?

A
  • molecules on the surface of one cells are recognised by receptors onthe adjacent cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe paracrine signalling? give 3 examples

A

signal released from a cell has an effect on neighbouring cell

  • fibroblast growth factor (prolif and diff)
  • transforming growth factor (growth, diff, prolif, apoptosis)
  • Wnt signalling (embroyo)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is chemotaxis?

A

movement of an immune cell along a concentration gradient

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

describe synaptic signalling?

A

nerve cells release the signal (NT) which binds to receptors on nerby cells

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

why can it take even days for the function of a cell to change?

A

function is dictated by the proteins within the cell

  • proteins will remain until they are degraded
  • O they remain doing their function until they are degraded
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe endocrine signalling?

A
  • hormones released act on other cells throughout body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

give examples of how the same NT can have different effects depending on which target it is acting on

A
  • Acetylcholine
    heart: acts on muscarinic receptors and causes a descrease in rate and force of contraction
    skeletal muscle cell: causes contraction
    salivary gland: granulation and release of saliva and enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which 2 enzymes are used in virtually all signalling pathways?

A

kinases and phosphatases

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

give an example of a kinase?

how does it work?

A

serine or serine-threonine kinase

  • a phosphate is taken from ATP by the kinase and added to the protein
  • phosphate is a -vely charged molecule O will affect aa R groups (pull away or closer so shape of mol changes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a secondary messenger?

A

they diffuse into the cell and activate other proteins

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

give an example of a secondary messenger

A

eg cAMP

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

what makes cAMP?

A

adenylate cyclase

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

what does GEF stand for?

Study These Flashcards
A

Guanine nucleotide exchange factor

18
Q

what does GAP stand for?

Study These Flashcards
A

GTPase accelerating protein

19
Q

do all cells have the same intracellular signalling mechanisms?

Study These Flashcards
A

yes, the parts that are different are the receptor at the top and effector protein at the bottom

20
Q

what is the function of cAMP?

Study These Flashcards
A

it activates protein kinase A

21
Q

cGMP is made by what? what is its function?

Study These Flashcards
A

guanylate cyclase

function: activate protein kinase G

22
Q

how is protein kinase C activated?

Study These Flashcards
A
  • Phospholipase C takes a phosphatidylinositol-bisphosphate and REMOVES THE HEAD GROUP leaving behind DIACYLGLYCEROL
  • hydrophilic head group (INOSITOL-TRISPHOSPHATE) DIFFUSES INTO CELL
  • binds intracellular receptors (IP3 receptors) on SER
  • IP3 receptors are CALCIUM channels and allow Ca release into cytoplasm
  • at membrane: DIACYLGLYCEROL binds to PROTEIN KINASE C, making it partially active
  • once the Ca released reaches PROTEIN KINASE C it becomes SUPERACTIVE
23
Q

where is protein kinase A and protein kinase G found?

Study These Flashcards
A

they are soluble and exist in cystoplasm

24
Q

where is protein kinase C found?

Study These Flashcards
A

in the membrane

25
describe how extracellular signals are amplified
- a SINGLE/small amount of signalling molecule which binds to a small number of receptors - to AMPLIFY signal, the receptors activate for eg anenylate cyclase which go on to activate a MUCH GREATER NUMBER of cAMP - the cAMP activates a greater number of enzymes, thus forming a greater amount of PRODUCT
26
describe an ion channel
- ligand gated hole in the membrane | - opens in response to an agonist
27
what are the 2 ways in which a hole can be formed in a membrane? what kinds of proteins form these channels?
- barrel of beta sheets - single transmembrane/ multi-transmembrane domains ALPHA helices formed from MULTIMERIC PROTEINS (quarternery proteins)( 3, 5 or 7 subunits)
28
GABA A and nicotinic Ach receptors have how many subunits?
- 5 subunit | - each subunit has 4 transmembrane domains
29
how do GABA A and nicotinic Ach receptors work?
- ligand binds | - protein conformation changes, ligand can O enter
30
how is variation in how tissues respond to the same NT created?
- DIFFERENT SUBUNIT expression
31
why are G protein coupled receptors so important?
because ~70% of drugs are made to bind to a G protein coupled receptor
32
G protein coupled receptors all share what?
- all have a TERTIARY protein receptor with 7 transmembrane domains - TRIMERIC G protein ( three parts- alpha, beta-gamma, target enzyme)
33
responses to activation of ion channel receptors tend to be what?
rapid, immediate changes
34
what is a metabotropic receptor?
a membrane receptor that acts through a SECONDARY messenger
35
how do G protein coupled receptors work?
- receptor activated when ligand BINDS - receptor chages SHAPE - shape change transmitted THROUGH the membrane to G protein alpha subunit which also changes shape - GDP is exchanged for GTP - G protein DISSOCIATES and becomes FUNCTIONAL - GTP BINDS to ALPHA subunit, and it diffuses within membrane and affects activity of target enzyme (activate or inhibit)
36
the N terminus and C terminus of the receptor are found WHERE
N terminus is EXTRACELLULAR | C terminus is INTRACELLULAR
37
the extracellular loops are called E1,2,3 etc, which loops does the ligand attach to?
E2 or E3
38
the intracellular (cytosolic) loops are called C1,2,3 etc, which loops does the G protein attach to?
C3 or C4
39
which subunits of the G protein are able to be attached to the membrane?
alpha and gamma (with beta inside it)
40
where is the beta subunit found?
INSIDE the gamma subunit, they function as one, they are never separate
41
which G protein subunit has a GTPase function?
only ALPHA subunit | beta-gamma subunit can act as INHIBITORY subunit
42
how are effector proteins associated with G protein coupled receptors ACTIVATED?
-

YEAR 2 S1 BIOCHEM (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions