Biological signalling molecules

Question 1

What is an endogenous signalling molecule?

Answer 1

Found within the body

Question 2

What is an exogenous I signalling molecule?

Answer 2

Natural, plant based

Question 3

What is an exogenous II signalling molecules?

Answer 3

Synthetic (man made)

Question 4

What are some parameters under homeostatic control?

Answer 4

Temperature
pH
Oxygen
Carbon dioxide
Glucose
Ions
Water

Question 5

Below what temperature is considered hypothermic?

Answer 5

35 degrees Celsius

Question 6

At what temperature does cardiac fibrillation occur?

Answer 6

26-28 degrees

Question 7

At what temperature range is regulation of own temperature impaired?

Answer 7

30-34 degrees

Question 8

Where are the receptors for amines and peptides to proteins found?

Answer 8

On the plasma membrane (not lipid soluble)

Question 9

Where are the receptors for lipophilic molecules eg steroids found?

Answer 9

Intracellular/nuclear

Question 10

What do amine endocrine signalling molecules do?

Answer 10

Cause change in membrane potential

Question 11

What do peptide to protein signalling molecules do?

Answer 11

Triggers synthesis of second messengers and protein kinase synthesis

Question 12

What do steroid signalling molecules do?

Answer 12

Controls transcription and stability of mRNAs

Question 13

Over what distance do paracrine signalling molecules operate?

Answer 13

20nm

Question 14

Which type of signalling molecules are neurotransmitters?

Answer 14

Paracrine

Question 15

What are some examples of local chemical mediators?

Answer 15

Cytokines eg histamine

Prostaglandins

Question 16

What is propanolol used for?

Answer 16

Treatment of hypertension - antagonises adrenaline/noradrenaline

Question 17

What is used to treat Parkinsonism?

Answer 17

Dopamine precursors and agents to inhibit its breakdown

Question 18

Name one example of an antidepressant

Answer 18

Fluoxetine - slows reuptake of serotonin

Question 19

What can be used to treat epilepsy?

Answer 19

GABA receptor modulators

Question 20

What can be used to treat migraines?

Answer 20

Serotonin agonists

Question 21

What can be used to treat inflammation?

Answer 21

Steroids - block inflammatory signal of local mediators

Question 22

What can be used to treat moderate pain?

Answer 22

NSAIDs block local mediator pain signal

Question 23

What can be used to treat respiratory inflammatory responses?

Answer 23

Adrenergic agonists

Leukotriene antagonists

Question 24

What does the mnemonic RITE stand for?

Answer 24

Receptors
Ion channels
Transporters
Enzymes

(Signalling molecule targets)

Question 25

What does the mnemonic KING stand for?

Answer 25

Types of receptors Kinase-linked receptors Ion channels (ligand gated) Nuclear/intracellular G-protein coupled receptors

Question 26

What do kinase linked receptors do?

Answer 26

Act via phosphorylation of certain groups

Question 27

What do ionotropic receptors do?

Answer 27

Ligand binds, allow ions currents and voltage change driving or modulating action potential generation in neurones and contraction in muscle

Question 28

What do nuclear/intracellular receptors do?

Answer 28

Ligand needs to be lipid soluble eg steroids | Can bind to gene transcription factor to activate/inactivate genes