Human Anatomy & Physiology - Chapter 3: Membrane Transport
Which membrane transport process consumes ATP and uses a carrier?
Active
Which carrier transports two or more solutes in opposite directions across a cell membrane?
Antiport
What are the membrane channels that allow the movement of water across a membrane called?
Aquaporins
Water and electrolytes can cross a cell membrane through which of the following?
Channels
Match the direction of particle movement with the term that describes this movement.
Down a gradient: from a region of high to low concentration Up a gradient: from a region of low to high concentration
The general term for the cell process in which the membrane invaginates, forming vesicles that bring extracellular particles or droplets of fluid into the cell, is known as ______ .
Endocytosis
Which form of vesicular transport uses motor proteins to bring fluid and solutes into the cell?
Endocytosis
Which are types of vesicular transport?
Endocytosis and exocytosis
In which process does a secretory vesicle fuse with a cell membrane and release its contents into the extracellular space?
Exocytosis
The vesicular transport process of discharging material from a cell is called _____ .
Exocytosis
What are all body fluids that are located outside of cells called?
Extracellular fluid
The process of using a carrier to passively transport a solute through a membrane down its concentration gradient is known as _______ diffusion.
Facilitated
Which mechanism of carrier-mediated transport moves a solute through a membrane without use of energy?
Facilitated diffusion
The greater or steeper the concentration gradient, the ______ the rate of diffusion.
Faster
The rate of diffusion across the cell membrane is ______ at high temperatures than at low temperatures.
Faster
Smaller molecules diffuse ______ larger molecules.
Faster than
When the concentration of a substance differs from one area to another, this creates a concentration _____.
Gradient
When the concentration of a substance gradually changes from one area to the next, we say it exhibits a concentration ______.
Gradient
The greater the concentration of a nonpermeating solute present in a solution, the ______ the osmotic pressure of that solution.
Higher
The physical force generated by a liquid, such as blood or tissue fluid, is known as _______ pressure.
Hydrostatic
Which pressure allows for the filtration of fluid from blood vessels into the extracellular fluid?
Hydrostatic
A cell placed into which solution will lose water by osmosis?
Hypertonic
A solution that has a lower osmotic pressure than the intracellular fluid of the cell and tends to cause osmotic swelling and lysis of cells is called a(n) ________ solution.
Hypotonic
Cells can ______ the rate of osmosis by installing more aquaporins.
Increase
The rate of diffusion is increased by ______ the surface area of the cell membrane.
Increasing
Tissue fluid is also called ______.
Interstitial fluid
When cells are placed in which solution, there is no change in cell volume or shape?
Isotonic
As the molecular weight of a substance increases, what happens to its diffusion rate?
It decreases.
As a membrane surface area increases, what happens to it's diffusion rate?
It increases.
As temperature increases, what happens to the rate of diffusion?
It increases.
Larger molecules diffuse through the cell membrane ______ than smaller molecules.
More slowly
By what term is the number of milliosmoles of solute per liter of water that is used to express the osmotic concentration of a solution known?
Osmolarity
At tissue capillary beds, fluid leaves the capillaries by filtration while it moves back into the capillaries by which process?
Osmosis
The movement of specifically water from an area of higher concentration to an area of lower concentration across a semipermeable membrane is called _______.
Osmosis
What is the net flow of water down its concentration gradient through a selectively permeable membrane called?
Osmosis
Transport mechanisms like filtration, facilitated diffusion, and osmosis are examples of which of the following forms of transport?
Passive (they don't require ATP)
Neutrophils engulf bacteria by surrounding them with pseudopods and drawing them into the cell by which process?
Phagocytosis
The process of engulfing particles (such as bacteria) by surrounding the particle and drawing it into the cell is referred to as ____ .
Phagocytosis
What drives filtration through a membrane?
Physical pressure
In which process does the plasma membrane dimple (or cave in) and take in droplets of ECF within a vesicle?
Pinocytosis
The process by which a cell can take in large droplets of ECF (water) is called _____ .
Pinocytosis
Which process uses a carrier to move a substance against its concentration gradient using ATP?
Primary active transport
In which process do receptors bind their ligand, cluster together into a pit, and then taken into the cell within a vesicle?
Receptor-mediated endocytosis
Mechanical pressure can be applied to one side of a membrane in order to drive water through the membrane against its concentration gradient. This process is called ______ osmosis.
Reverse
When all carriers have bound ligand and no further ligand can be transported they are said to be what?
Saturated
Sodium-glucose transporters do not directly use ATP. Their ability to move glucose is due to the previous active removal of sodium from the cell. The sodium gradient that resulted from active transport "drives" the transporter, bringing both sodium and glucose into the cell. This is an example of which of the following?
Secondary active transport
Which membrane type allows some things through and restricts the passage of others?
Selectively permeable
Which of the following assures that the ECF concentration of sodium remains much higher than the ICF concentration?
Sodium-potassium pump
Plasma membranes are selectively permeable. What does this mean?
Some compounds can permeate (pass through) the membrane while others cannot.
A carrier protein binds and transports only its particular ligand. What quality does this demonstrate?
Specificity
Which type of carrier moves two solutes through a plasma membrane in the same direction at the same time?
Symport
Which of the following correctly defines tonicity?
The ability of a solution to cause osmosis, affecting volume and pressure in the cell
As a solute concentration rises, its rate of transport through a membrane increases up to the point where all the carriers are saturated. This point of saturation is called what?
The transport maximum
The concentration of solutes in a cell affects the fluid volume and pressure within the cell. This is referred to as the _______ of the solution.
Tonicity
A process in which a substance is taken up at one side of a cell and released from the other side is called ______ . This allows substances to be transported across an entire cell.
Transcytosis
When all carriers are saturated, the transport of the molecule levels off at a rate called what?
Transport maximum
What is a carrier that carries only one type of solute called?
Uniport
Which of the following moves large particles and fluid droplets across the cell membrane?
Vesicular transport
A hydration sphere consists of a solute particle surrounded by ______ molecules.
Water
Reverse osmosis uses a mechanical pressure to drive water through a membrane ______ its concentration gradient.
against
If an antiport carrier moves solutes in opposite directions across a cell membrane, this is called _____ .
countertransport
Passive mechanisms of membrane transport ______.
do not require ATP
In blood capillaries, blood pressure forces fluid through gaps in the capillary wall in a process called _______.
filtration or capillary filtration
A solution that has a higher osmotic pressure than the intracellular fluid of cells and tends to cause the cells to undergo osmotic shrinkage is called a(n) _______ solution.
hypertonic
Cells placed in a(n) ______ solution will swell and burst due to water moving into the cell.
hypotonic
Consider two solutions of different sodium concentrations separated by a selectively permeable membrane. The net movement of water across the membrane will be from the area of ______ sodium concentration to the area of ______ sodium concentration.
lower, higher
The number of milliosmoles per liter of solution is the ______ of a solution.
osmolarity
In which process do receptors bind their ligand, cluster together into a pit, and then taken into the cell within a vesicle?
receptor-mediated endocytosis
The type of carrier protein that moves two solutes, such as glucose and sodium, in the same direction across a membrane is a(n) ______ .
symport or contransport
A carrier that transports only one type of solute at a time is called a(n) ______ .
uniporter
What are three mechanisms of carrier-mediated transport?
- facilitated diffusion - secondary active transport - primary active transport
Which factors would increase the rate of diffusion?
-Increased concentration difference -Increased cell surface area -Decreased molecular weight of diffusing compound
Which of the following molecules can readily diffuse through a cell membrane?
-Nonpolar molecules -Hydrophobic molecules -Lipid-soluble molecules
Mechanisms for moving substances across the plasma membrane that require the use of cellular ATP include ______.
-vesicular transport -active transport
Which salt solution would be isotonic to human red blood cells?
0.9%
The Na+-K+ pump moves ______ Na+ ions from the ICF to the ECF while simultaneously moving ______ K+ ions from the ECF into the ICF.
3, 2
What is a protein that participates in transmembrane transport called?
A carrier
Water molecules can form a loose reversible relationship with a solute particle by assembling into what?
A hydration sphere.
In which process does a solute bind to a carrier in the plasma membrane that then changes shape and releases the solute to the other side of the membrane?
Carrier-mediated transport
What is the net movement of particles from a region of higher concentration to a region of lower concentration called?
Diffusion
The heart generates pressure that drives fluid out of the capillaries and into the spaces between cells. What is this process called?
Capillary filtration
Facilitated diffusion, primary, and secondary active transport are all mechanisms of which of the following?
Carrier-mediated transport
Movement of gas molecules (oxygen and carbon dioxide) between the air in the lungs and the blood or between the blood and the tissues is by which process?
Diffusion