All GRE Subject Test: Biochemistry, Cell, and Molecular Biology Resources
Example Questions
Example Question #1 : Cellular Junctions
What is the main purpose of gap junctions?
Allows molecules and ions to travel between cells
Prevents cells from separating from one another
Allows large molecules to move between cells
Prevents water from moving between cells
Allows molecules and ions to travel between cells
Gap junctions can be thought of as small tunnels between cells. They allow for the immediate transport of ions and molecules between the cells. Gap junctions are prominent in cardiac myocytes, and help spread action potentials via electrical synapses to coordinate the contraction of the heart.
Example Question #2 : Signals, Communication, And Junctions
Which cellular junction will be most useful in preventing the movement of material between cell membranes?
Hemidesmosomes
Tight junctions
Gap junctions
Desmosomes
Tight junctions
The movement of substances between cells is most commonly controlled by tight junctions. These junctions can be regulated, which can alter how strongly they resist the movement of material between cells, like those in the digestive tract during absorption.
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