Exam 3: Cell-cell interactions (Class 2) Flashcards
What are the five categories of signaling?
- direct intercellular signaling
- contact-dependent signaling
- autocrine signaling
- paracrine signaling
- endocrine signaling
What is direct intercellular signaling?
Cell junctions allow signaling molecules to pass from one cell to another at rate of diffusion (via gap junction)
What type of junctions are used in direct intercellular signaling?
Gap junctions
How does contact dependent signaling work?
Receptors on adjacent cells bind to other cell surface molecules
What do the cell surface molecules in contact dependent signaling function as?
Signals
What is the difference between direct intercellular signaling and contact dependent signaling?
Direct intercellular: passed from cytoplasm to cytoplasm
Contact dependent: adjacent cell membranes
What is autocrine signaling?
Cells secrete signaling molecules that bind to its own surface or other neighboring cells
What is paracrine signaling?
Same as autocrine, but no receptors so a cell cannot receive its own signal
Endocrine signaling
Signals travel long distance through blood stream, take a long time to fade
What are the 4 stages of cell signaling?
- Signal reception
- Signal processing/transduction
- Signal response
- Signal deactivation
What occurs in signal reception (step 1)?
Signal receptors are bound
What are the two type of signals
- Hormones
- Other cell-cell signals
The presence of what dictates which cells will be able to respond to a particular hormone
appropriate receptor proteins
What does protein function depend on? (3 factors)
- Binding
- Shape
- Location
When the signal binds to the receptor, what happens to the receptor
It undergoes a conformational change
Signal receptors that bind to lipid-soluble hormones are located where
Inside the cell
Signal receptors that bind to non lipid-soluble hormones are located where
in the plasma membrane
Lipid-soluble steroid hormones are ___ soluble in water
less
Estrogen, progesterone, glucocorticoids, and ecdysone are examples of what
hormone response elements
The hormone receptor complex binds to…
the hormone response elements (HRE)
Where is the hormone-receptor complex transported to and for what
the nucleus, for altering gene expression