Summary
Energy sensors AMPK and mTOR balance catabolism and growth according to nutrient availability.
In depth
AMPK is activated by high AMP/ATP, stimulating catabolism and inhibiting anabolism; metformin and exercise activate it. mTORC1 senses amino acids and growth factors to promote protein synthesis; rapamycin inhibits it and extends lifespan in animals.
AMPK is the energy gauge; mTOR is the nutrient sensor. Their balance determines growth versus conservation. Dysregulation is linked to cancer and diabetes.
Example: metformin activates AMPK.
AMP-activated protein kinase (AMPK) senses low energy: when ATP falls and AMP rises, AMPK is switched on, activating catabolic pathways (glucose uptake, fatty acid oxidation, autophagy) and turning off anabolic ones. Metformin, exercise and caloric restriction activate it.
The mTOR complex 1 (mTORC1) senses amino acids, growth factors and energy, and when nutrients are abundant promotes protein and lipid synthesis and cell growth while inhibiting autophagy. Rapamycin inhibits mTOR and extends lifespan in mice. The two kinases work in opposition and are central in ageing, cancer and metabolic disease.
Example: lack of food activates AMPK, which inhibits mTOR.
Key idea: they act like the cell's fuel gauge and growth switch.
Frequently asked questions
What is AMPK and mTOR Signalling?
Energy sensors AMPK and mTOR balance catabolism and growth according to nutrient availability.
Which area of biology covers AMPK and mTOR Signalling, and how advanced is it?
AMPK and mTOR Signalling is one of the 53 topics in Metabolism & Bioenergetics. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Anabolism and Catabolism, Brown Fat Thermogenesis, Hormonal Control of Metabolism.
Can you give an example of AMPK and mTOR Signalling?
Fasting increases AMPK activity.
What should I learn before AMPK and mTOR Signalling?
Work through the Beginner topics in Metabolism & Bioenergetics first, such as Metabolism, Anabolism and Catabolism, ATP, then return to AMPK and mTOR Signalling. Advanced topics assume the Intermediate vocabulary.
What topics are related to AMPK and mTOR Signalling?
The closest topics to AMPK and mTOR Signalling are Anabolism and Catabolism, Brown Fat Thermogenesis, Hormonal Control of Metabolism, Metabolic Syndrome. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand AMPK and mTOR Signalling?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for AMPK and mTOR Signalling. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
How is AMPK and mTOR Signalling different from Anabolism and Catabolism?
AMPK and mTOR Signalling: Energy sensors AMPK and mTOR balance catabolism and growth according to nutrient availability. Anabolism and Catabolism: Anabolic reactions build complex molecules using energy; catabolic reactions break them down to release energy. Read both side by side and note what each one explains.
How should I study AMPK and mTOR Signalling step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Anabolism and Catabolism and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.