Cell Signaling
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Phosphotases add or remove phosphate groups in a process called what?
remove ; dephosphorylation
What are the three main components of the cytoskeleton
Intermediate filaments
Microtubules
Microfilaments
Microfilaments are also known as
actin filaments
Adenylyl cyclase is activated by
G-protein-coupled receptors (GPCRs)
what are the two types of receptors?
1. membrane
2. intracellular
Microfilaments play what role?
Involvement in cell movement, shape changes, and muscle contraction
What make up cilia and flagella in cells?
microtubules
What does phosphodiesterase do?
converts cAMP → AMP
How does phosphodiesterase regulate cAMP levels in the cell?
it breaks down cAMP into AMP, stopping the signal and preventing overstimulation of pathways.
What types of molecules can pass through gap junctions?
Ions (Ca²⁺, Na⁺, K⁺), small signaling molecules (cAMP, ATP), and small nutrients.
motor What is the role of motor proteins?
facilitating intracellular transport by moving molecules
how does epinephrine induce "fight or flight"?
it activates G-proteins and cAMP production -> activates protein kinases and leads to the mobilization of energy
What does adenylyl cyclase do?
convert ATP → cAMP
These cell junctions provide strong adhesion between adjacent cells, especially in tissues that experience mechanical stress (e.g., skin, heart)
desmosomes
What are cadherins, and what do they do?
calcium dependent proteins that help cells stick together in tissues
How is calcium signaling involved in neurotransmitter release?
When an action potential reaches a neuron’s synapse, voltage-gated calcium channels open, allowing Ca²⁺ influx, which triggers vesicle fusion and neurotransmitter release.
What happens when phosphodiesterase activity is inhibited?
cAMP levels remain elevated, leading to prolonged activation of signaling pathways
What is the difference between tight vs. gap junctions?
tight junctions: seal the space between adjacent cells, preventing the passage of substances between them
gap junctions: channels that allow direct communication between adjacent cells by letting small molecules and ions pass through
How do intermediate filaments provide structural support to cells?
They form a strong, rope-like network that resists mechanical stress and helps maintain cell shape, especially in skin, muscle, and nerve cells.