Chapter 11 - Cell Communication Flashcards
(37 cards)
The three steps in cell communication
1) Signal reception
2) Signal transduction
3) Cellular response
__________ are converted to responses within the cell
External signals…
Cells _____, ____, and ___ to signals
receive, send, and respond
Definition of Epinephrine (adrenaline)
A hormone secreted by the brain into the blood that stimulates the breakdown of stored polysaccharide glycogen within liver cells & skeletal muscle
Cells in a multicellular organism communicate via ____ targeted for cells that may or may not be adjacent
…signaling molecules…
Local signaling
animal cells communicate by direct contact (w/ cell junctions & cell-surface molecules)
Many animal and plant cells have cell junctions that ____ ____ to the cytoplasm’s/adjacent cells
directly connect
Plasmodesmata definition
Channels that connect plant cells and water & small solutes (and proteins & RNA) pass from cell to cell
Gap junctions provide ___ ___ btwn adjacent cells
cytoplasmic channels
Paracrine signaling
Another method animal cells use to communicate.
- uses secreted messenger molecules that travel only short distances
- ex: Growth factors (stimulate nearby target cells to grow & divide)
Synaptic signaling definition
- neurotransmitters released in response to electric signal
- occurs in animal nervous system
Long distance signaling
Uses hormones (plants & animals)
In ___ ___ (in animals) specialized cells release hormones, which travel to target cells via the circulatory system (bloodstream)
…endocrine signaling…
The ability of a cell to respond to a signal depends on whether it has a ___________
…receptor specific to that signal
3 stages of cell signaling
-Reception, transduction, and response
-A series of steps by which a signal on a cell’s surface is converted into a specific cellular response
Signal reception (general)
The target cell detects a signaling molecule (ligand) coming from outside the cell that binds to a receptor protein on the cell surface
Signal transduction (general)
The binding of the signaling molecule alters the receptor and initiates a signal transduction pathway
Cellular response (general)
The transduced signal triggers a specific response in the target cell
A signaling molecule binds to a receptor protein, causing it to _____ ______
…change shape
The binding btwn a ligand and receptor is _____ ______
highly specific
_______________ is generally the initial transduction of the signal
A shape change in a receptor…
Most signal receptors are _____ _______ proteins, but others are located inside the cell
…plasma membrane…
The 3 main types of plasma membrane:
-G protein-coupled receptors
-Receptor tyrosine kinases (growth factors)
-Ion channel receptors
G protein-coupled receptors (GPCRs)
-Cell-surface transmembrane receptors that work w/ G protein
-Largest family of human cell-surface receptors
-G proteins bind energy-rich GTP (Guanonsine-5’-triphosphate)
-Most water-soluble signal molecules bind to specific sites on receptor proteins that transmit info from extracellular environment to inside of cell
