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A signalling molecule, epinephrine (adrenaline), is released from the adrenal gland when a human feels threatened - VCE - SSCE Biology - Question 3 - 2013 - Paper 1
Question 3
A signalling molecule, epinephrine (adrenaline), is released from the adrenal gland when a human feels threatened. The molecule is transported in the bloodstream and... show full transcript
Worked Solution & Example Answer:A signalling molecule, epinephrine (adrenaline), is released from the adrenal gland when a human feels threatened - VCE - SSCE Biology - Question 3 - 2013 - Paper 1
Step 1
a. To which group of signalling molecules does epinephrine belong?
Answer
Epinephrine belongs to the group of signalling molecules known as hormones. Hormones are chemical messengers that are produced in glands and released into the bloodstream to regulate various physiological processes in different parts of the body.
Step 2
b. Receptors for epinephrine are found on the exterior surface of the plasma membrane of cells. What does this suggest about the nature of the epinephrine molecule?
Answer
The presence of receptors for epinephrine on the exterior surface of the plasma membrane indicates that epinephrine is likely a polar molecule. This suggests that it cannot easily pass through the lipid bilayer of the plasma membrane and instead relies on binding to specific receptors on the cell surface to initiate its effects.