Signalling Molecules

Question 1

What does the regulation of flow mean?

Answer 1

Getting molecules and energy flowing together:
Right place
Right amount
Right time

Question 2

What are the different types of signalling molecules?

Answer 2

Endogenous (within the body)
Exogenous I (natural based)
Exogenous II (Synthetic)

Question 3

What are the requirements for cell homeostasis?

Answer 3

Substrate supply system
Product distribution system
Waste removal system
Stable physiochemical environment
Responsive control system

Question 4

What are examples of physiochemical parameters under homeostatic control?

Answer 4

Temperature
pH
Concentration of ions inside/outside cells
O2, CO2, H2O
Glucose

Question 5

Describe the type of systems in the environments of our bodies?

Answer 5

External environment: open (variable, wide-ranging)
Extracellular space: closed (tight limits)
Intracellular space: closed (limits)

Question 6

How does homeostasis control the physiochemical environment and what are the steps involved?

Answer 6

Negative Feedback Loop -
Change in environment
Change in system
Sensor produces error signal
Error signal is processed by controller
Controller produces an actuating signal (SP - SO)
Actuating signal causes change in system

Question 7

What is pharmacology?

Answer 7

Study of molecular signallers regulating physiological function

Question 8

What are the main Extracellular signalling groups?

Answer 8

Endocrine
Paracrine
Autocrine

Question 9

What are the three types of endocrine signalling molecules?

Answer 9

Catecholamines
Peptides - Proteins
Steroid Hormones

Question 10

Describe the following characteristics of catecholamines:
Solubility:
Plasma half-life:
Action time:
Receptor location:
Mechanism:

Answer 10

Solubility: hydrophillic
Plasma half-life: seconds
Action time: milliseconds - seconds
Receptor location: membrane
Mechanism: change membrane potential

Question 11

Describe the following characteristics of peptides-proteins:
Solubility:
Plasma half-life:
Action time:
Receptor location:
Mechanism:

Answer 11

Solubility: hydrophillic
Plasma half-life: minutes
Action time: minutes - hours
Receptor location: membrane
Mechanism: produce secondary messengers

Question 12

Describe the following characteristics of steroid hormones:
Solubility:
Plasma half-life:
Action time:
Receptor location:
Mechanism:

Answer 12

Solubility: lipophillic
Plasma half-life: hours
Action time: hours - days
Receptor location: cytosol/nuclear
Mechanism: affect production of proteins

Question 13

What are major type of paracrine signalling molecules?

Answer 13

Neurotransmitters

Question 14

What are the major types of neurotransmitters and examples?

Answer 14

ACh

Monoamines: Adrenaline, Nor-adrenaline, Dopamine, Serotonin

Amino acids: Glutamate, Glycine, G-amino Butyric Acid (GABA)

Question 15

Are the major neurotransmitters excitatory or inhibitory?

Answer 15

ACh - Exc
Adrenaline - Exc
Nor-adrenaline - Exc
Dopamine - Exc + Inh
Serotonin - Exc
Glutamate - Exc
Glycine - Inh
GABA (G-amino Butyric Acid) - Inh

Question 16

What are the 4 types of drug targets?

Answer 16

Receptors
Ion channels (regulate cell membrane potential)
Transporters (active transport of substances)
Enzymes (change activity of enzyme)

Question 17

What are the 4 types of receptors?

Answer 17

Ligand-gated (ionotropic) - allows flow of ions
GPCR (metabotropic) - activate G-Proteins
Kinase-linked - phosphorylate Proteins
Nuclear - change protein production