BIOL 1201 EXAMS: LATEST A+ GUIDE WITH ESSENTIAL
QUESTIONS AND ANSWERS
local signaling
animal cells may communicate by direct contact, or cell-cell recognition (paracrine and synaptic
signaling)
cell junctions
Animal and plant cells; directly connect the cytoplasm of adjacent cells
paracrine signaling
the target cells lie near the secreting cells
synaptic signaling
a nerve cell releases neurotransmitter molecules into a synapse, stimulating the target cell
endocrine (hormonal) signaling
Specialized endocrine cells secrete hormones into body fluids, often blood. Hormones reach
virtually all body cells, but are bound only by some cells.
cell-cell recognition
two cells in an animal may communicate by interaction between molecules protruding from
their surfaces
three stages of cell signaling
reception, transduction, response
reception
The target cell's detection of a signal molecule coming from outside the cell.
transduction
the binding of the signaling molecule alters the receptor and initiates a signal transduction
pathway; occurs in a series of steps
response
the transduced signal triggers a specific response in the target cell
signal transduction pathway
A series of steps linking a mechanical or chemical stimulus to a specific cellular response
, ligand
Signal molecule that binds to the receptor
three main types of membrane receptors
-G protein-coupled receptors
-Receptor tyrosine kinases
-Ion channel receptors
G protein-coupled receptors (GPCRs)
cell-surface transmembrane receptors that work with the help of a G protein
Receptor Tyrosine Kinases (RTKs)
membrane receptors that transfer phosphate groups from ATP to another protein
ligand-gated ion
acts as a gate that opens and closes when the receptor changes shape
intracellular receptors
receptors located inside the cell rather than on its cell membrane
phosphorylation
the addition of a phosphate group to a molecule
dephosphorylation
removal of a phosphate group from a molecule
second messengers
Small, non-protein water soluble molecules or ions that send messages throughout the cells by
diffusion.
common second messengers
cyclic AMP and calcium ions
cyclic AMP (cAMP)
A compound formed from ATP that acts as a second messenger; one of the most commonly
used
adenylyl cyclase
an enzyme in the plasma membrane, converts ATP to cAMP in response to an extracellular
signal
QUESTIONS AND ANSWERS
local signaling
animal cells may communicate by direct contact, or cell-cell recognition (paracrine and synaptic
signaling)
cell junctions
Animal and plant cells; directly connect the cytoplasm of adjacent cells
paracrine signaling
the target cells lie near the secreting cells
synaptic signaling
a nerve cell releases neurotransmitter molecules into a synapse, stimulating the target cell
endocrine (hormonal) signaling
Specialized endocrine cells secrete hormones into body fluids, often blood. Hormones reach
virtually all body cells, but are bound only by some cells.
cell-cell recognition
two cells in an animal may communicate by interaction between molecules protruding from
their surfaces
three stages of cell signaling
reception, transduction, response
reception
The target cell's detection of a signal molecule coming from outside the cell.
transduction
the binding of the signaling molecule alters the receptor and initiates a signal transduction
pathway; occurs in a series of steps
response
the transduced signal triggers a specific response in the target cell
signal transduction pathway
A series of steps linking a mechanical or chemical stimulus to a specific cellular response
, ligand
Signal molecule that binds to the receptor
three main types of membrane receptors
-G protein-coupled receptors
-Receptor tyrosine kinases
-Ion channel receptors
G protein-coupled receptors (GPCRs)
cell-surface transmembrane receptors that work with the help of a G protein
Receptor Tyrosine Kinases (RTKs)
membrane receptors that transfer phosphate groups from ATP to another protein
ligand-gated ion
acts as a gate that opens and closes when the receptor changes shape
intracellular receptors
receptors located inside the cell rather than on its cell membrane
phosphorylation
the addition of a phosphate group to a molecule
dephosphorylation
removal of a phosphate group from a molecule
second messengers
Small, non-protein water soluble molecules or ions that send messages throughout the cells by
diffusion.
common second messengers
cyclic AMP and calcium ions
cyclic AMP (cAMP)
A compound formed from ATP that acts as a second messenger; one of the most commonly
used
adenylyl cyclase
an enzyme in the plasma membrane, converts ATP to cAMP in response to an extracellular
signal
