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Bio 411: Exam 4 Questions with Answers (100% Correct
Answers)
What does Cell signaling require? Answer: Signaling Cell, Signaling
molecule, responding cell, and receptor.
Four Steps of Cell Signaling Answer: receptor activation, signal
transduction, cellular response, and signal termination.
Endocrine Signaling Answer: long distance, uses the circulatory system
Paracrine Signaling Answer: close distance
Autocrine Signaling Answer: occurs when the same cell makes and
responds to the signal
Contact-Dependent Signaling Answer: signaling between two touching
cells
Signaling Molecule Answer: ligand; receptor binding site = ligand-
binding site
Receptors Answer: Exist as either 'on' or 'off'
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Intracellular Receptors Answer: reside inside the cell and bind ligands
that can pass through the plasma membrane. Some are in the nucleus
and regulate transcription.
Cell Surface Receptors Answer: typically bind polar molecules since they
can't pass through the plasma membrane
An Indivdual Cell Answer: Can have thousands of different receptors
Surface Receptor Categories Answer: G-protein coupled receptors,
receptor kinases, and ligand-gated ion channels.
G-Protein Coupled Receptors Answer: receptor that: interacts with g
proteins on the membrane, has three subunits (Alpha, Beta and
Gamma), are active with GTP bound and inactive with GDP bound,
subunits join together when GDP is bound ect.
Receptor Kinases Answer: ligand binds to two receptors, which causes
them to dimerize, dimerization activates kinase domains inside the cell,
kinase domains phosphorylate each other ect.
© 2025 All rights reserved
Bio 411: Exam 4 Questions with Answers (100% Correct
Answers)
What does Cell signaling require? Answer: Signaling Cell, Signaling
molecule, responding cell, and receptor.
Four Steps of Cell Signaling Answer: receptor activation, signal
transduction, cellular response, and signal termination.
Endocrine Signaling Answer: long distance, uses the circulatory system
Paracrine Signaling Answer: close distance
Autocrine Signaling Answer: occurs when the same cell makes and
responds to the signal
Contact-Dependent Signaling Answer: signaling between two touching
cells
Signaling Molecule Answer: ligand; receptor binding site = ligand-
binding site
Receptors Answer: Exist as either 'on' or 'off'
© 2025 All rights reserved
, 2
Intracellular Receptors Answer: reside inside the cell and bind ligands
that can pass through the plasma membrane. Some are in the nucleus
and regulate transcription.
Cell Surface Receptors Answer: typically bind polar molecules since they
can't pass through the plasma membrane
An Indivdual Cell Answer: Can have thousands of different receptors
Surface Receptor Categories Answer: G-protein coupled receptors,
receptor kinases, and ligand-gated ion channels.
G-Protein Coupled Receptors Answer: receptor that: interacts with g
proteins on the membrane, has three subunits (Alpha, Beta and
Gamma), are active with GTP bound and inactive with GDP bound,
subunits join together when GDP is bound ect.
Receptor Kinases Answer: ligand binds to two receptors, which causes
them to dimerize, dimerization activates kinase domains inside the cell,
kinase domains phosphorylate each other ect.
© 2025 All rights reserved
