Quiz 5 Flashcards
Lectures 19 & 20 and Nerve Lab (40 cards)
cells that are talking put out signaling molecules called
ligands
target cells
cells that are listening
what do target cells have
receptor that the ligand attaches to
ligand/receptor complex
transmit a signal into the cell (signal transduction)
signal transduction leads to
a cellular response ex. altered metabolism, altered gene expression, altered cell shape or mobility
what is cell signaling based off of
distance and type of cell
autocrine signaling
cell signaling to itself
ex. immune cells - can amplify their response to infections and injuries
Cancer cells - can stimulate their growth
direct cell-to-cell contact
Direct contact between ligand and receptor
ex. embryonic development and wound healing
paracrine signaling
cells signaling to nearby cells
Ex. embryonic development - development of the spinal cord
endocrine signaling
signaling through the circulatory system
ex. hormones
synaptic signaling
signaling by a nerve cell through a synapse to another cell
hydrophobic ligands
- can diffuse across the plasma membrane
- bind to intracellular receptors (IRs) in the cytoplasm
- have a binding domain that causes the IR to give a signal into the cell
types of membrane-bound receptors
- Ion channel receptors: ligand binding opens the ion channel across the membrane
- Enzymatic (catalytic receptor): ligand binding activates the enzymatic activity of the intracellular signaling domain
- G Protein-Coupled Receptors (GPCRs)
Hydrophilic Ligands
- can’t diffuse across plasma membrane
- need membrane-bound receptor
Agonists
drugs that mimic the action of ligands that would normally bind to the receptor (activate receptors)
antagonist
bind to but do NOT activate receptors
Blocks other ligands from binding to receptor
- ex. naloxone/Narcan
Embryonic development
gene-directed changes that occur after fertilization that lead to the formation of an organism
4 subprocesses
1. Cell division - cleavage
2. Cell differentiation - cells become particular cell types
3. Pattern formation - cells detect positional info in embryo, a body plan takes shape
4. Morphogenesis - development and final shaping of specific anatomical structures
Cleavage
animal embryos have a period of rapid cell division after fertilization called cleavage
Cells in embryo divide but don’t grow
Number of cells ↑, size of cells ↓
Size of embryo doesn’t change
Cell differentiation
In the 1-16 cell stage, human embryonic cells can become any cell type
cells differentiate: commit to becoming particular cell types
What determines a cell’s fate?
Exposure to ligands
Physical contact w/ other cells
