The triacylglycerol molecule, common in fat tissue in animals, is composed of three fatty acids (long hydrocarbon chains) and a glycerol molecule. Which of the following statements describes the relationship between the structure and the function of the triacylglycerol molecule? * A. It has a hydrophilic (polar) “head” and two hydrophobic (non-polar) “tails” that allow it to form a phospholipid bilayer in membranes.
B. It has hydrophilic (polar) bonds that allow it to function as the most powerful immediate-energy compound in organisms.
C. It has hydrophobic (non-polar) bonds and hydrophobic hydrocarbon chains that allow it to store energy in a stable chemical compound.
D. It has hydrophobic (non-polar) steroids between the phospholipids that allow it to regulate membrane fluidity.

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).