The lipids that compose the cell membrane are arranged with "heads" and "tails" such that:
A) The "heads" are in contact with extracellular and intracellular fluid and the "tails" oriented away from these fluids
B) The "tails" are in contact with extracellular and intracellular fluid and the "heads" oriented away from these fluids
C) Half of all "heads" and "tails" are in contact with extracellular fluid
D) Both "heads" and "tails" are in contact with intracellular fluid
A
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Indicate whether the statement is true or false
The bone that is attached to the eardrum is called the ________; the bone that is connected to the oval window is called the ________
a) anvil (incus); stirrup (stapes) b) hammer (malleus); anvil (incus) c) stirrup (stapes); hammer (malleus) d) hammer (malleus); stirrup (stapes)
Despite its dangers, a young man continues to take cocaine because of the feelings of euphoria it produces for him. This powerful arousal of his nervous system is probably due to cocaine's ability to ______
a. inhibit enzymes that break down neurotransmitters b. increase the release of neurotransmitters c. block the receptor sites for neurotransmitters d. prevent neurotransmitters from being reabsorbed into the synaptic vesicles
A ternary receptor model suggests that:
a. only ligands with a high affinity for a receptor can activate a receptor. b. a G-protein can prevent a ligand from binding to a receptor. c. receptor actions depend on an interaction between a ligand, receptor, and G-protein. d. receptor efficacy only pertains to metabotropic receptors.