AP Biology / Unit 4: Cell Communication and Cell Cycle
4.3 Signal Transduction Pathways
Notes
- G protein-coupled receptors activate G proteins, often making second messengers like cAMP.
- Receptor tyrosine kinases phosphorylate themselves and relay proteins.
- Phosphorylation cascades amplify the signal: one signal activates many molecules.
- Mutations in pathway proteins can cause diseases like cancer.
Practice
cAMP is a:
Relays the signal inside the cell.
A phosphorylation cascade lets one ligand:
Each step activates many of the next.
A mutation keeps a relay protein always "on." Likely result:
Constant activation, as in some cancers.
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