BIOL 150 Exam 3 Questions with
complete solution (9 pgs)
Sunlight absorbed by chlorophyll is used to energize electrons, which are
passed from high energy electron acceptors, through the electron transport
system, and is eventually used to reduce NADPH. From what molecules were
the electrons obtained? - correct answer ✔Water
Both chloroplasts and mitochondria use chemiosmosis to phosphorylate ADP.
Where are the ATPsynthases located in chloroplasts? - correct answer
✔thylakoid membranes
Photosynthesis is a process that captures light energy and converts it into
chemical energy that can be used to make sugars. What happens when a
plant cell is placed in the dark? - correct answer ✔The plant will metabolize
glucose using glycolysis and oxidative phosphorylation.
RUBISCO (ribulose bis phosphate carboxylase oxygenase) is an important
enzyme in chloroplasts. What does RUBISCO do? - correct answer ✔It is a
Calvin cycle enzyme that captures carbon dioxide and fixes it on ribulose bis
phosphate
Most of the ATP produced in chloroplasts during photosynthesis is used -
correct answer ✔to assemble sugar
Bacteria that associate with Hawaiian bobtail squid can produce light but only
under certain conditions. What are these conditions? - correct answer
✔Bacteria must grow to a certain concentration that promotes their signaling
to each other to produce
light.
, GLUT4 is a channel in muscle and liver cells that can allow facilitated diffusion
of glucose across the plasma membrane. GLUT4 normally is located in the
membranes of secretory vesicles in the cytoplasm. The display of GLUT4 is
stimulated when the cells are exposed to insulin.
What would you predict would happen if GLUT4 proteins lacked ER signal
sequences? - correct answer ✔The cell would be unable to take up glucose
even if insulin is present.
What do protein kinases do in a cell? - correct answer ✔Protein kinases add
phosphate groups to proteins.
How is cyclic AMP (cAMP) produced in a cell? - correct answer ✔When
activated, adenylyl cyclases produce cAMP from ATP
Protein phosphatases are a family of enzymes that specifically remove
phosphate groups from proteins that were added by protein kinases.
Vanadate is an inhibitor of phosphatases in eukaryotic cells. What effect
would vanadate have on the response of cells to signals received by receptor
kinases? - correct answer ✔The response of the cell would last longer than it
normally would
How does a G-protein become inactivated? - correct answer ✔G-proteins
hydrolyze the GTP to form GDP and release phosphate. The G-protein with
GDP bound
can no longer bind and activate the downstream molecule.
Where would you expect to find a receptor for a protein hormone like insulin? -
correct answer ✔on the plasma membrane
complete solution (9 pgs)
Sunlight absorbed by chlorophyll is used to energize electrons, which are
passed from high energy electron acceptors, through the electron transport
system, and is eventually used to reduce NADPH. From what molecules were
the electrons obtained? - correct answer ✔Water
Both chloroplasts and mitochondria use chemiosmosis to phosphorylate ADP.
Where are the ATPsynthases located in chloroplasts? - correct answer
✔thylakoid membranes
Photosynthesis is a process that captures light energy and converts it into
chemical energy that can be used to make sugars. What happens when a
plant cell is placed in the dark? - correct answer ✔The plant will metabolize
glucose using glycolysis and oxidative phosphorylation.
RUBISCO (ribulose bis phosphate carboxylase oxygenase) is an important
enzyme in chloroplasts. What does RUBISCO do? - correct answer ✔It is a
Calvin cycle enzyme that captures carbon dioxide and fixes it on ribulose bis
phosphate
Most of the ATP produced in chloroplasts during photosynthesis is used -
correct answer ✔to assemble sugar
Bacteria that associate with Hawaiian bobtail squid can produce light but only
under certain conditions. What are these conditions? - correct answer
✔Bacteria must grow to a certain concentration that promotes their signaling
to each other to produce
light.
, GLUT4 is a channel in muscle and liver cells that can allow facilitated diffusion
of glucose across the plasma membrane. GLUT4 normally is located in the
membranes of secretory vesicles in the cytoplasm. The display of GLUT4 is
stimulated when the cells are exposed to insulin.
What would you predict would happen if GLUT4 proteins lacked ER signal
sequences? - correct answer ✔The cell would be unable to take up glucose
even if insulin is present.
What do protein kinases do in a cell? - correct answer ✔Protein kinases add
phosphate groups to proteins.
How is cyclic AMP (cAMP) produced in a cell? - correct answer ✔When
activated, adenylyl cyclases produce cAMP from ATP
Protein phosphatases are a family of enzymes that specifically remove
phosphate groups from proteins that were added by protein kinases.
Vanadate is an inhibitor of phosphatases in eukaryotic cells. What effect
would vanadate have on the response of cells to signals received by receptor
kinases? - correct answer ✔The response of the cell would last longer than it
normally would
How does a G-protein become inactivated? - correct answer ✔G-proteins
hydrolyze the GTP to form GDP and release phosphate. The G-protein with
GDP bound
can no longer bind and activate the downstream molecule.
Where would you expect to find a receptor for a protein hormone like insulin? -
correct answer ✔on the plasma membrane
