Lesson 3: Chemical Signalling

Question 1

Correlation between Body Mass and Speed of Neurone Impulses

Answer 1

Larger body mass correlates with slower neuron impulse speeds due to longer distances signals must travel.

Question 2

what are ligands?

Answer 2

signalling molecules

Question 3

steps of chemical signalling

Answer 3

Release of a ligand from a signaling cell.
Transport of the ligand to the target cell (e.g., via blood).
Binding of the ligand to a receptor on the target cell.
Activation of intracellular reactions.
Cellular response (e.g., gene expression).
Termination of the signal (e.g., ligand degradation).

Question 4

Types of Signaling Molecules

Answer 4

Hormones
Neurotransmitters
Cytokines
Calcium Ions

Question 5

Hormones

Answer 5

Secreted by endocrine glands.
Long-lasting effects.
Can bind to intracellular or surface receptors.

Question 6

Neurotransmitters

Answer 6

Transmit signals between neurons.
Short-lived effects.

Question 7

Cytokines

Answer 7

Small proteins involved in immune responses.

Question 8

Calcium Ions

Answer 8

Act as secondary messengers in processes like muscle contraction.

Question 9

Types of Hormones

Answer 9

Amino Acid/Amine Hormones
Peptide Hormones
Lipid-Based Hormones

Question 10

Amino Acid/Amine Hormones examples

Answer 10

Epinephrine and melatonin

Question 11

Peptide Hormones examples

Answer 11

Insulin and Oxytocin

Question 12

Lipid-Based Hormones examples

Answer 12

Testosterone and oestradiol