E109 MIDTERM 1 EXAM QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026
Hyperosmotic - Answers solution that has a higher solute concentration
Hypoosmotic - Answers Solution that has a lower solute concentration
4 primary functions of membrane proteins - Answers Transport, structural proteins, enzymatic
activity, membrane receptors
Carrier protein - Answers undergo conformational changes. never forms an open channel between
two sides of the membrane
Channel protein - Answers create a water-filled pore. may be gated, opening and closing in response
to signals
simple diffusion - Answers the movement of molecules from high to low concentration through the
membrane
facilitated diffusion - Answers requires a transport protein to move molecules from high to low
concentration
secondary active transport - Answers does not use ATP directly. it uses the energy stored in an ion
gradient that was created by primary active transport (potential energy)
primary active transport - Answers directly hydrolyzes ATP to pump molecules against concentration
gradient
Definition + local or long communication?
Gap Junctions - Answers LOCAL: form direct cytoplasmic connections between adjacent cells
Definition + local or long communication?
Contact-dependent signals - Answers LOCAL: require interaction between membrane molecules on
two cells
Definition + local or long communication?
Autocrine/Paracrine Signals - Answers LOCAL:
autocrine- act on the same cell that secreted them
paracrine- are secreted by one cell and diffuse to adjacent cell
Definition + local or long communication?
Endocrine system (hormones) - Answers LONG: hormones are secreted by endocrine glands or cells
into the blood. only target cells with receptors for the hormone respond to the signal
Definition + local or long communication?
Nervous system (neurotransmitters) - Answers LONG: chemicals secreted by neurons that diffuse
across a small gap to the target cell
agonists - Answers mimic the signal and activates a receptor leading to a response
antagonists - Answers bind to the receptor and block activity, resulting in no response
synergism - Answers combined effects is greater than the simple addition of effects
additive - Answers adds effects
anterior endocrine cells - Answers receives a neurohormone (releasing) from the hypothalamus ->
triggers synthesis of trophic hormones that are then released to other target organs that release their
own hormones
posterior: extension of brain - Answers stores and secretes neurohormones made in the
hypothalamus
Endocrine pathologies: Target cell pathologies - Answers mutation in or down regulation of target cell
receptor
Endocrine pathologies: Hypersecretion - Answers too much! loss of inhibitory feedback, excess
hormone production
Endocrine pathologies: Hyposecretion - Answers too little! deficiency in hormone synthesis, over
inhibition of release
Nernst Equation - Answers for single ion. calculates equilibrium potential
Goldman-Hodgkin-Katz equation - Answers for multiple ions. calculates resting potential, taking into
account many ions' permeabilities
Resting membrane potential is closer to the ___ potential - Answers Potassium potential because of
potassium leak channels. At rest, permeability of K+ is higher than that of Na+
Concentration gradients are upheld by the ___ - Answers Na+/K+ ATPase pump (2 sodium out, 2
potassium in)
What affects AP propogation rates? - Answers resistance of axon to current loss:
- larger diameter=less current flow resistance
Hyperosmotic - Answers solution that has a higher solute concentration
Hypoosmotic - Answers Solution that has a lower solute concentration
4 primary functions of membrane proteins - Answers Transport, structural proteins, enzymatic
activity, membrane receptors
Carrier protein - Answers undergo conformational changes. never forms an open channel between
two sides of the membrane
Channel protein - Answers create a water-filled pore. may be gated, opening and closing in response
to signals
simple diffusion - Answers the movement of molecules from high to low concentration through the
membrane
facilitated diffusion - Answers requires a transport protein to move molecules from high to low
concentration
secondary active transport - Answers does not use ATP directly. it uses the energy stored in an ion
gradient that was created by primary active transport (potential energy)
primary active transport - Answers directly hydrolyzes ATP to pump molecules against concentration
gradient
Definition + local or long communication?
Gap Junctions - Answers LOCAL: form direct cytoplasmic connections between adjacent cells
Definition + local or long communication?
Contact-dependent signals - Answers LOCAL: require interaction between membrane molecules on
two cells
Definition + local or long communication?
Autocrine/Paracrine Signals - Answers LOCAL:
autocrine- act on the same cell that secreted them
paracrine- are secreted by one cell and diffuse to adjacent cell
Definition + local or long communication?
Endocrine system (hormones) - Answers LONG: hormones are secreted by endocrine glands or cells
into the blood. only target cells with receptors for the hormone respond to the signal
Definition + local or long communication?
Nervous system (neurotransmitters) - Answers LONG: chemicals secreted by neurons that diffuse
across a small gap to the target cell
agonists - Answers mimic the signal and activates a receptor leading to a response
antagonists - Answers bind to the receptor and block activity, resulting in no response
synergism - Answers combined effects is greater than the simple addition of effects
additive - Answers adds effects
anterior endocrine cells - Answers receives a neurohormone (releasing) from the hypothalamus ->
triggers synthesis of trophic hormones that are then released to other target organs that release their
own hormones
posterior: extension of brain - Answers stores and secretes neurohormones made in the
hypothalamus
Endocrine pathologies: Target cell pathologies - Answers mutation in or down regulation of target cell
receptor
Endocrine pathologies: Hypersecretion - Answers too much! loss of inhibitory feedback, excess
hormone production
Endocrine pathologies: Hyposecretion - Answers too little! deficiency in hormone synthesis, over
inhibition of release
Nernst Equation - Answers for single ion. calculates equilibrium potential
Goldman-Hodgkin-Katz equation - Answers for multiple ions. calculates resting potential, taking into
account many ions' permeabilities
Resting membrane potential is closer to the ___ potential - Answers Potassium potential because of
potassium leak channels. At rest, permeability of K+ is higher than that of Na+
Concentration gradients are upheld by the ___ - Answers Na+/K+ ATPase pump (2 sodium out, 2
potassium in)
What affects AP propogation rates? - Answers resistance of axon to current loss:
- larger diameter=less current flow resistance
