Cell signalling and apoptosis
How cells talk to each other: ligands and receptors, the main receptor families, second messengers and signal amplification, then how a cell dies cleanly (apoptosis) or by accident (necrosis), and what diseases and drugs make of it.
- 32 cards
- 3 topics
- Free
The outline, topic by topic
Each topic is weighted the way the exam weighs it.
- Concepts
- Scenarios
- Understand
A few cards from the deck
Ligand: what is it?
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A signal molecule (hormone, neurotransmitter, growth factor) that binds a receptor specifically.
An agonist drug mimics a ligand, an antagonist blocks its place.
During a heart attack, heart muscle cells starved of oxygen die by…
- Necrosis, with inflammation
- Apoptosis without inflammation
- Mitosis
- Meiosis
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Necrosis, with inflammation
The released enzymes (troponin) enter the blood and are used for diagnosis.
G protein-coupled receptor: what is it?
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A membrane receptor that, once activated, switches on a G protein, which produces second messengers.
It is the target of a large share of drugs, such as beta-blockers.
Why can a single ligand produce a huge effect in the cell?
- The ligand multiplies
- The receptor divides
- It is impossible
- Each step of the cascade activates many molecules at the next: the signal is amplified
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Each step of the cascade activates many molecules at the next: the signal is amplified
One adrenaline molecule can release millions of glucose molecules.
Receptor tyrosine kinase: what is it?
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A membrane receptor that, once activated, adds phosphates to tyrosines and starts a signalling cascade.
It is the receptor for insulin and many growth factors.
In the embryo, the fingers separate as the tissue between them disappears. Through which mechanism?
- Necrosis
- Apoptosis
- An infection
- Meiosis
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Apoptosis
Programmed death sculpts organs without harming them.