MSCI 660 INTRACELLULAR MEMBRANE
TRAFFIC AND CELLULAR SORTING 2026 CELL
BIOLOGY ASSESSMENT TEST PAPER
QUESTIONS SOLUTIONS GRADED A+
◉ Cytoplasm.
Answer: Contents of the main compartment of the cell, excluding the
nucleus and membrane-bounded compartments such as
endoplasmic reticulum and mitochondria.
◉ Organelle.
Answer: Membrane-enclosed compartment in a eukaryotic cell that
has a distinct structure, macromolecular composition, and function.
◉ Signal peptide.
Answer: Protein sorting signal that consists of a short continuous
sequence of amino acids.
◉ Nuclear transport signal.
Answer: Sorting signal contained in the structure of macromolecules
and complexes that are transported from the nucleus to the cytosol
through nuclear pore complexes.
, ◉ Nuclear pore complex.
Answer: Large multiprotein structure forming a channel through the
nuclear envelope that allows selected molecules to move between
nucleus and cytoplasm.
◉ Ran.
Answer: Monomeric GTPase present in both cytosol and nucleus
that is required for the active transport of macromolecules into and
out of the nucleus through nuclear pore complexes.
◉ Nuclear lamina.
Answer: Fibrous meshwork of proteins on the inner surface of the
inner nuclear membrane.
◉ Importin.
Answer: Protein that binds nuclear localization signals and
facilitates the transport of proteins with these signals from the
cytosol into the nucleus through nuclear pore complexes.
◉ Nuclear localization signal.
Answer: Sorting signal found in proteins destined for the nucleus
and which enable their selective transport into the nucleus from the
cytosol through the nuclear pore complexes.
TRAFFIC AND CELLULAR SORTING 2026 CELL
BIOLOGY ASSESSMENT TEST PAPER
QUESTIONS SOLUTIONS GRADED A+
◉ Cytoplasm.
Answer: Contents of the main compartment of the cell, excluding the
nucleus and membrane-bounded compartments such as
endoplasmic reticulum and mitochondria.
◉ Organelle.
Answer: Membrane-enclosed compartment in a eukaryotic cell that
has a distinct structure, macromolecular composition, and function.
◉ Signal peptide.
Answer: Protein sorting signal that consists of a short continuous
sequence of amino acids.
◉ Nuclear transport signal.
Answer: Sorting signal contained in the structure of macromolecules
and complexes that are transported from the nucleus to the cytosol
through nuclear pore complexes.
, ◉ Nuclear pore complex.
Answer: Large multiprotein structure forming a channel through the
nuclear envelope that allows selected molecules to move between
nucleus and cytoplasm.
◉ Ran.
Answer: Monomeric GTPase present in both cytosol and nucleus
that is required for the active transport of macromolecules into and
out of the nucleus through nuclear pore complexes.
◉ Nuclear lamina.
Answer: Fibrous meshwork of proteins on the inner surface of the
inner nuclear membrane.
◉ Importin.
Answer: Protein that binds nuclear localization signals and
facilitates the transport of proteins with these signals from the
cytosol into the nucleus through nuclear pore complexes.
◉ Nuclear localization signal.
Answer: Sorting signal found in proteins destined for the nucleus
and which enable their selective transport into the nucleus from the
cytosol through the nuclear pore complexes.
