MSCI 660 INTRACELLULAR MEMBRANE
TRAFFIC AND CELLULAR SORTING 2026
ENDOMEMBRANE SYSTEM WORKBOOK
SOLVED QUESTIONS COMPILATION
◉ True or False: The most important contribution of the citric acid
cycle to energy metabolism is the extraction of high-energy
electrons during the oxidation of acetyl CoA to CO2.
Answer: True. The citric acid cycle extracts high-energy electrons,
which are crucial for ATP production.
◉ True or False: Each respiratory enzyme complex in the electron-
transport chain has a greater affinity for electrons than its
predecessors.
Answer: True. This allows electrons to pass sequentially from one
complex to another until they are transferred to oxygen.
◉ True or False: An average person contains 50 kg of ATP, which is
required to meet their daily energy needs.
Answer: False. An average person does not contain that much ATP;
the body recycles ATP continuously.
,◉ True or False: The chloroplast can be viewed as a greatly enlarged
mitochondrion.
Answer: True. This analogy helps to understand the similarities in
function between the two organelles.
◉ True or False: When chlorophyll absorbs a photon, the excited
electron is rapidly transferred from one chlorophyll molecule to
another until it reaches the photochemical reaction center.
Answer: True. This transfer is essential for the conversion of light
energy into chemical energy.
◉ True or False: The mitochondrial genetic code differs slightly from
the nuclear code but is identical across all species.
Answer: False. The mitochondrial genetic code differs among
species.
◉ What are cytoplasmic contents?
Answer: Contents of a cell that are contained within its plasma
membrane but, in the case of eukaryotic cells, outside the nucleus.
◉ What is the cytosol?
Answer: Contents of the main compartment of the cell, excluding the
nucleus and membrane-bounded compartments such as
endoplasmic reticulum and mitochondria.
, ◉ What is a membrane-enclosed compartment?
Answer: A compartment in a eukaryotic cell that has a distinct
structure, macromolecular composition, and function.
◉ What is a signal sequence?
Answer: A protein sorting signal that consists of a short continuous
sequence of amino acids.
◉ What is a nuclear pore complex?
Answer: A large multiprotein structure forming a channel through
the nuclear envelope that allows selected molecules to move
between the nucleus and cytoplasm.
◉ What is a GTPase?
Answer: A monomeric GTPase present in both cytosol and nucleus
that is required for the active transport of macromolecules into and
out of the nucleus.
◉ What is the nuclear lamina?
Answer: A fibrous meshwork of proteins on the inner surface of the
inner nuclear membrane.
◉ What is a nuclear localization signal?
TRAFFIC AND CELLULAR SORTING 2026
ENDOMEMBRANE SYSTEM WORKBOOK
SOLVED QUESTIONS COMPILATION
◉ True or False: The most important contribution of the citric acid
cycle to energy metabolism is the extraction of high-energy
electrons during the oxidation of acetyl CoA to CO2.
Answer: True. The citric acid cycle extracts high-energy electrons,
which are crucial for ATP production.
◉ True or False: Each respiratory enzyme complex in the electron-
transport chain has a greater affinity for electrons than its
predecessors.
Answer: True. This allows electrons to pass sequentially from one
complex to another until they are transferred to oxygen.
◉ True or False: An average person contains 50 kg of ATP, which is
required to meet their daily energy needs.
Answer: False. An average person does not contain that much ATP;
the body recycles ATP continuously.
,◉ True or False: The chloroplast can be viewed as a greatly enlarged
mitochondrion.
Answer: True. This analogy helps to understand the similarities in
function between the two organelles.
◉ True or False: When chlorophyll absorbs a photon, the excited
electron is rapidly transferred from one chlorophyll molecule to
another until it reaches the photochemical reaction center.
Answer: True. This transfer is essential for the conversion of light
energy into chemical energy.
◉ True or False: The mitochondrial genetic code differs slightly from
the nuclear code but is identical across all species.
Answer: False. The mitochondrial genetic code differs among
species.
◉ What are cytoplasmic contents?
Answer: Contents of a cell that are contained within its plasma
membrane but, in the case of eukaryotic cells, outside the nucleus.
◉ What is the cytosol?
Answer: Contents of the main compartment of the cell, excluding the
nucleus and membrane-bounded compartments such as
endoplasmic reticulum and mitochondria.
, ◉ What is a membrane-enclosed compartment?
Answer: A compartment in a eukaryotic cell that has a distinct
structure, macromolecular composition, and function.
◉ What is a signal sequence?
Answer: A protein sorting signal that consists of a short continuous
sequence of amino acids.
◉ What is a nuclear pore complex?
Answer: A large multiprotein structure forming a channel through
the nuclear envelope that allows selected molecules to move
between the nucleus and cytoplasm.
◉ What is a GTPase?
Answer: A monomeric GTPase present in both cytosol and nucleus
that is required for the active transport of macromolecules into and
out of the nucleus.
◉ What is the nuclear lamina?
Answer: A fibrous meshwork of proteins on the inner surface of the
inner nuclear membrane.
◉ What is a nuclear localization signal?
