Dose Response Curve
Introduced| English |
|---|
| dose-response curve/dəʊs rɪˈspɒns kɜːv/ |
| response/rɪˈspɒns/ |
| threshold/ˈθreʃəʊld/ |
How much harm from how much?
- A tiny dose of a chemical may do nothing.
- A large dose of the same chemical may kill.
- To show this, scientists draw a dose-response curve 剂量反应曲线.
- It plots the effect against the dose.
Reading the curve
- The dose goes along the bottom; the response 反应 goes up the side.
- As the dose rises, the effect usually gets stronger.
- The curve starts low and climbs upward.
- At high doses the harm can become severe or lethal.
A dose-response curve shows how…
A dose-response curve plots the response (effect) against the dose of a substance.
The threshold
- Many substances have a threshold 阈值 dose.
- Below the threshold, there is no visible effect.
- Above it, the effect begins and grows.
- Finding the threshold helps set safe exposure limits.
Little effect or strong effect?
Sort each dose by the size of the response it causes on the curve.
On most dose-response curves, as the dose increases, the effect…
Generally, more dose means more effect — the curve rises as the dose increases.
The dose below which there is no visible effect is called the ____.
The threshold is the lowest dose that starts to cause a measurable effect.
The dose makes the poison
- Almost any substance can harm you at a high enough dose.
- Even water is deadly if you drink far too much.
- And a "poison" may be harmless in a tiny amount.
- So it is the dose, not just the substance, that decides the harm.
"The dose makes the poison" - even a safe substance can harm you at a high enough dose.
Almost anything - even water - becomes harmful at a high enough dose. The dose is what matters.
Select all true statements about dose-response curves.
The curve links dose to effect and helps set safe limits. The effect very much depends on the dose.
The big idea is centuries old: "the dose makes the poison." There's no such thing as a substance that is simply "toxic" or "safe" — it depends entirely on how much. Water, oxygen, even vitamins become harmful at high enough doses; deadly chemicals may be harmless in trace amounts. The dose-response curve is how scientists pin down exactly where "safe" turns into "harmful".
Reading a real curve:
- At a very low dose (below the threshold), the test animals show no effect — the curve sits flat at the bottom.
- As the dose climbs, more and more show harm, and the curve rises.
- Past a high dose, nearly all are affected — the curve levels off near the top.
- Regulators read the threshold off this curve to set a legal "safe" limit.
A dose-response curve plots the response (effect) against the dose of a substance. Usually the effect grows as the dose rises. Many substances have a threshold dose below which there is no visible harm. The core principle is "the dose makes the poison" — almost anything is harmful at a high enough dose, and the curve shows where safe becomes harmful.