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WorksheetsBIOG 240 Cell Bio Exam 1 Review
Total questions: 10
Worksheet time: 20mins
Which of the following best describes how neurotransmitters are released?
Calcium ions enter the neuron and activate synaptotagmins which displaced complexins from the vesicle SNARE proteins and the vesicle fuses to the membrane, releasing the neurotransmitters.
Sodium ions enter the neuron and the resulting depolarization causes the neurotransmitter containing vesicles to release their contents into the synaptic cleft.
Exportin proteins are activated by GTP which causes ion channels to open, allowing for diffusion of neurotransmitters into the cleft.
Where is the ER signal sequence located?
Carboxy terminus (C-terminus)
Wherever there is a long chain of aromatic amino acids.
Amine terminus (N-terminus)
Wherever there is a short region of hydrophobic amino acids.
How would a loss-of-function mutation in a t-SNARE protein affect vesicle fusion?
It will have no effect.
Vesicles will not be able fuse to the membrane.
v-SNARE proteins will still function and thus vesicle fusion will still occur.
All endosomes become lysosomes due to the proton pumps located in the endosome membranes.
True
False
Which of the following would lead to a stronger muscle contraction?
Decreased frequency of action potentials to the muscle.
Increased frequency of action potentials to the muscle.
Stronger depolarization with each action potential to the muscle.
Proteins pass through the nuclear pore in what state?
Unfolded state.
Folded state.
They pass through the nuclear pore co-translationally and in their folded state.
They pass through the nuclear pore co-translationally and in their unfolded state.
How would removing an ER signal sequence affect the trafficking of an extracellular protein?
The protein will diffuse through the membrane and into the extracellular fluid.
The protein will remain in the cytosol.
The protein will become embedded in the ER membrane.
The protein will end up being trafficked into the golgi and exocytosed.
K+ ions are associated with what event of the action potential?
Depolarization of the membrane.
Repolarization of the membrane.
Repolarization and hyperpolarization of the membrane.
Which kind of lipid is the most prevalent in the lipid bilayer?
Phospholipids
Cholesterol.
Sphingosides.
Acetylcholine.
Eurypharynx pelecanoides is an eel that lives in the deep sea, where there is little sunlight and the water is frigid. What type of membrane composition would you expect to see in this eel?
High levels of cholesterol and unsaturated fatty acids.
High levels of cholesterol and saturated fatty acids.
Low levels of cholesterol and high levels of unsaturated fatty acids.
Low levels of cholesterol and high levels of saturated fatty acids.
