# Explain why the effects of adrenaline on target cells are short-lived compared with the effects of steroid hormones.

> OCR A-Level Biology A (H420) — 5.4 Hormonal communication · Explain · 4 marks

> Adrenaline is a hormone released from the adrenal medulla in response to stress. Steroid hormones, such as cortisol, are released from the adrenal cortex and also help the body respond to stress, but over a longer timescale.

## Mark scheme (4 marks)

1. Adrenaline cannot enter the cell / is not lipid-soluble, so acts via a membrane-bound receptor and a second messenger system
2. The second messenger (cAMP) is rapidly broken down by phosphodiesterase, so the intracellular signal is quickly terminated
3. Steroid hormones are lipid-soluble so they cross the cell surface membrane and bind to receptors in the cytoplasm or nucleus
4. Steroid hormones directly alter gene expression / act as transcription factors, leading to sustained protein synthesis, prolonging the effect

## Key terms

- [adrenaline](https://www.gradenine.co.uk/glossary/adrenaline)
- [steroid hormones](https://www.gradenine.co.uk/glossary/steroid-hormones)

## Related

- [Revision notes for OCR A-Level Biology A (H420)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-the-effects-of-adrenaline-e0ed622b) · Published by Druglandscape Ltd.