BIO 612 EXAM 1 QUESTIONS AND ANSWERS
100% VERIFIED
Homeostasis refers to maintaining a relatively stable internal environment. The "internal
environment" is: - ANSWER plasma, interstitial fluid, and transcellular fluid
Example of a positive feedback: - ANSWER During a blood clot, platelets release ADP,
which stimulates platelet aggregation, causing platelets to release more ADP
The ________ acts as the primary integrating center for the thermoregulatory system in
the body. - ANSWER hypothalamus
In ____________, blood pressure has dropped as a result of excessive sweating and
over-taxing the body's heat loss mechanisms. - ANSWER heat exhaustion
True of the cell membrane: - ANSWER - cholesterol influences how fluid the membrane
is
- carbohydrates associate with proteins and lipids on the extracellular side of the
membrane
- there are many different kinds of membrane proteins
The asymmetry of the surfaces of epithelial cells is due to the presence of _______
between the cells in the tissue. - ANSWER tight junctions
In some cases, signals originating within one cell can diffuse directly to a neighboring
cell's cytoplasm through: - ANSWER gap junctions
Anesthetics cross the cell membranes in nerve tissue relatively easily. Therefore,
anesthetics have a: - ANSWER high partition coeficient
,Potassium and Sodium true statement - ANSWER The potassium ion's nucleus has a
larger radius, so therefore the radius of the hydrated ion will be smaller
Which of the following transport processes is the least like to get saturated?
a) channel protein
b) facilitated diffusion
c) primary active transport
d) secondary active transport - ANSWER a) channel protein
Which of the following does NOT directly determine the rate at which an ion will move
passively across a membrane?
a) magnitude of the driving force
b) permeability of the membrane
c) membrane surface area
d) amount of ATP available
e) concentration gradient - ANSWER d) amount of ATP available
To bring glucose into the cell, the cell uses facilitated diffusion through GLUT carrier.
However, liver cells are able to convert glycogen to glucose, thereby making the
intracellular glucose concentration higher than the extracellular glucose concentration.
What would happen to the facilitated diffusion of glucose when this occurs? - ANSWER
The movement of glucose will reverse directions, and glucose will leave the cell through
the GLUT carriers
A distinction between channel proteins and carrier proteins is that: - ANSWER Carrier
proteins are never open to both the ECF and the ICF simultaneously, whereas channel
proteins can be open to both fluids at the same time.
True for the three transport mechanisms (facilitated diffusion, primary active transport,
secondary active transport) - ANSWER - the transport mechanism is specific for a
particular solute
, - the transport mechanism requires a transmembrane protein
- there is a limit to the total number of molecules that can be transported per unit of time
- the transport can be increased by increasing the number of transport molecules in the
plasma membrane
True statements about the Na+/K+ pump - ANSWER - three sodium ions are moved out of
the cell per ATP
- it is a form of primary active transport
- the pump is also an enzyme
- two potassium ions are move into the cell per ATP
The concentration of an anion inside a cell is 0.3%. The concentration of this anion
outside the cell is 0.1%. How would the cell obtain more of this ion inside the cell? -
ANSWER active transport
Ouabain, an inhibitor of the Na+/K+ pump, cannot pass through cell membranes. What
would happen to glucose uptake in the small intestine if ouabain were applied to the
apical side of the epithelium? - ANSWER Glucose uptake will not change
The nonselective process whereby extracellular fluid can enter the cell in vesicle is: -
ANSWER pinocytosis
Assume that a membrane separated side A (pure water) from side B (a solution
containing a solute to which the membrane is not permeable). What would happen? -
ANSWER - net water movement will be from side A to side B
- side B has a higher osmotic pressure than side A
- water will diffuse until stopped by an opposing hydrostatic pressue
Two compartments are separated by a membrane that is permeable only to water and to
yellow dye molecules. Compartment A is filled with an aqueous solution of yellow dye,
and compartment B is filled with an aqueous solution of an equal concentration of blue
dye. Given that yellow plus blue makes green, what color will compartment A be if the
100% VERIFIED
Homeostasis refers to maintaining a relatively stable internal environment. The "internal
environment" is: - ANSWER plasma, interstitial fluid, and transcellular fluid
Example of a positive feedback: - ANSWER During a blood clot, platelets release ADP,
which stimulates platelet aggregation, causing platelets to release more ADP
The ________ acts as the primary integrating center for the thermoregulatory system in
the body. - ANSWER hypothalamus
In ____________, blood pressure has dropped as a result of excessive sweating and
over-taxing the body's heat loss mechanisms. - ANSWER heat exhaustion
True of the cell membrane: - ANSWER - cholesterol influences how fluid the membrane
is
- carbohydrates associate with proteins and lipids on the extracellular side of the
membrane
- there are many different kinds of membrane proteins
The asymmetry of the surfaces of epithelial cells is due to the presence of _______
between the cells in the tissue. - ANSWER tight junctions
In some cases, signals originating within one cell can diffuse directly to a neighboring
cell's cytoplasm through: - ANSWER gap junctions
Anesthetics cross the cell membranes in nerve tissue relatively easily. Therefore,
anesthetics have a: - ANSWER high partition coeficient
,Potassium and Sodium true statement - ANSWER The potassium ion's nucleus has a
larger radius, so therefore the radius of the hydrated ion will be smaller
Which of the following transport processes is the least like to get saturated?
a) channel protein
b) facilitated diffusion
c) primary active transport
d) secondary active transport - ANSWER a) channel protein
Which of the following does NOT directly determine the rate at which an ion will move
passively across a membrane?
a) magnitude of the driving force
b) permeability of the membrane
c) membrane surface area
d) amount of ATP available
e) concentration gradient - ANSWER d) amount of ATP available
To bring glucose into the cell, the cell uses facilitated diffusion through GLUT carrier.
However, liver cells are able to convert glycogen to glucose, thereby making the
intracellular glucose concentration higher than the extracellular glucose concentration.
What would happen to the facilitated diffusion of glucose when this occurs? - ANSWER
The movement of glucose will reverse directions, and glucose will leave the cell through
the GLUT carriers
A distinction between channel proteins and carrier proteins is that: - ANSWER Carrier
proteins are never open to both the ECF and the ICF simultaneously, whereas channel
proteins can be open to both fluids at the same time.
True for the three transport mechanisms (facilitated diffusion, primary active transport,
secondary active transport) - ANSWER - the transport mechanism is specific for a
particular solute
, - the transport mechanism requires a transmembrane protein
- there is a limit to the total number of molecules that can be transported per unit of time
- the transport can be increased by increasing the number of transport molecules in the
plasma membrane
True statements about the Na+/K+ pump - ANSWER - three sodium ions are moved out of
the cell per ATP
- it is a form of primary active transport
- the pump is also an enzyme
- two potassium ions are move into the cell per ATP
The concentration of an anion inside a cell is 0.3%. The concentration of this anion
outside the cell is 0.1%. How would the cell obtain more of this ion inside the cell? -
ANSWER active transport
Ouabain, an inhibitor of the Na+/K+ pump, cannot pass through cell membranes. What
would happen to glucose uptake in the small intestine if ouabain were applied to the
apical side of the epithelium? - ANSWER Glucose uptake will not change
The nonselective process whereby extracellular fluid can enter the cell in vesicle is: -
ANSWER pinocytosis
Assume that a membrane separated side A (pure water) from side B (a solution
containing a solute to which the membrane is not permeable). What would happen? -
ANSWER - net water movement will be from side A to side B
- side B has a higher osmotic pressure than side A
- water will diffuse until stopped by an opposing hydrostatic pressue
Two compartments are separated by a membrane that is permeable only to water and to
yellow dye molecules. Compartment A is filled with an aqueous solution of yellow dye,
and compartment B is filled with an aqueous solution of an equal concentration of blue
dye. Given that yellow plus blue makes green, what color will compartment A be if the
