Chapter 17: Cell Signaling Flashcards
what are the 4 steps in cell signaling?
- ligand/receptor binding
- activation of signal transduction
- relay of signal to the interior of the cell
- cellular responses/changes in gene expression
what are the 2 modes of cell signaling?
- direct cell-to-cell-signaling
- signaling by secreted molecules
explain direct cell-to-cell signaling
direct interaction of a cell w/ its neighbor or the cell matrix
what type of cell signaling is important in early development?
direct cell-to-cell
what are the 3 types of signaling by secreted molecules?
- endocrine signaling
- paracrine signaling
- autocrine signaling
describe endocrine signaling
- signaling molecules are secreted by specialized endocrine cells & carried through the circulatory system
endocrine signaling acts on target cell at
distant body sites
what is an example of endocrine signaling molecule
hormones
describe paracrine signaling
signaling molecules act locally & affect the behavior of nearby cells
what is an example of a paracrine signaling molecule?
neurons via neurotransmitters
describe autocrine signaling
cells respond to their own signaling molecules
what is an example of an autocrine signaling molecule?
T lymphocytes & cancer cells
what are the 2 types of signaling molecules?
- non-surface receptor-binding ligands
- cell surface receptor ligands
give some examples of non-surface receptor-binding ligands
- steroid hormones
- thyroid hormone
- retinoic acid
- vitamin D3
- nitric oxide
- carbon monoxide
steroid hormones are synthesized from
cholesterol
steroid hormones are VERY
hydrophobic
give 3 examples of steroid hormones
- sex steroids
- mineralocorticoids
- corticosteroids
give 3 examples of sex steroids
- testosterone
- estrogen
- progesterone
what is an example of corticosteroids
glucocorticoids
what is considered to be a very important signaling molecule?
nitric oxide
steroid hormone receptors are typically found on the
inside of the cell
with non-surface receptor-binding ligands, after the intracellular receptors bind to the ligands they
diffuse across the membrane
what are the 4 main examples of cell surface receptor ligands
- neurotransmitters
- peptide hormones
- growth factors
- eicosanoids
give 5 examples of a neurotransmitter
- acetylcholine
- dopamine
- epinephrine
- serotonin
- GABA