Cell Membrane Transport Flashcards
What is the primary function of the cell membrane?
To regulate the movement of substances in and out of the cell.
True or False: Passive transport requires energy.
False
Fill in the blank: Substances move from an area of _____ concentration to an area of _____ concentration in passive transport.
high, low
What are the two main types of transport mechanisms across the membrane?
Passive transport and active transport.
Name a type of passive transport.
Diffusion.
What is osmosis?
The diffusion of water across a selectively permeable membrane.
True or False: Facilitated diffusion requires a transport protein.
True
What is active transport?
The movement of substances against their concentration gradient, requiring energy.
Which cellular structure is primarily involved in active transport?
Protein pumps.
What is the sodium-potassium pump?
A type of active transport mechanism that moves sodium out of the cell and potassium into the cell.
Fill in the blank: _____ transport does not require energy.
Passive
What is endocytosis?
The process by which cells engulf substances from their external environment.
What is exocytosis?
The process by which cells expel materials to the outside of the cell.
True or False: Bulk transport is a form of active transport.
True
What is the role of carrier proteins in facilitated diffusion?
They help transport specific substances across the membrane.
Multiple Choice: Which of the following is NOT a type of passive transport? A) Diffusion B) Osmosis C) Active transport D) Facilitated diffusion
C) Active transport
What type of molecules typically use simple diffusion to cross the membrane?
Small, nonpolar molecules.
Fill in the blank: The _____ gradient is the difference in concentration of a substance across a membrane.
concentration
What is the main difference between primary and secondary active transport?
Primary active transport uses ATP directly, while secondary active transport uses the energy from the movement of other ions.
True or False: Water can pass through the cell membrane easily without any assistance.
True
What is a common example of a substance that requires facilitated diffusion?
Glucose.
Multiple Choice: Which process involves the formation of vesicles? A) Diffusion B) Osmosis C) Endocytosis D) Facilitated diffusion
C) Endocytosis
What is the function of aquaporins?
To facilitate the transport of water across cell membranes.
Fill in the blank: Active transport often involves the use of _____ to move substances.
ATP
What type of transport uses a concentration gradient as an energy source?
Secondary active transport.
True or False: All types of transport across the membrane occur at the same rate.
False
What is cellular transport?
The movement of substances into and out of cells.
True or False: Cellular transport can occur via passive and active mechanisms.
True
What is passive transport?
The movement of substances across a cell membrane without the use of energy.
Fill in the blank: The primary factor that determines the type of transport used is the __________ of the substance.
concentration gradient
What is active transport?
The movement of substances against their concentration gradient, requiring energy.
Which type of transport moves substances from an area of low concentration to an area of high concentration?
Active transport
Name one factor that affects the rate of diffusion in passive transport.
Temperature
True or False: Facilitated diffusion requires energy input.
False
What role do transport proteins play in cellular transport?
They assist in moving substances across the cell membrane.
Which type of transport is characterized by the use of vesicles?
Bulk transport or vesicular transport
Multiple Choice: Which of the following is NOT a factor influencing cellular transport? A) Size of the molecule B) Membrane permeability C) Color of the molecule D) Concentration gradient
C) Color of the molecule
What is osmosis?
The diffusion of water across a selectively permeable membrane.
Fill in the blank: The cell membrane is described as __________ because it allows certain substances to pass while blocking others.
selectively permeable
True or False: Larger molecules typically require active transport mechanisms.
True
What is the main energy source for active transport?
ATP (adenosine triphosphate)
Which type of transport can occur through ion channels?
Facilitated diffusion
Multiple Choice: Which type of cellular transport would likely be used for glucose? A) Simple diffusion B) Facilitated diffusion C) Active transport D) All of the above
B) Facilitated diffusion
What is the significance of the concentration gradient in cellular transport?
It determines the direction of movement for substances.
Fill in the blank: __________ transport does not require the input of energy.
Passive
True or False: Small, nonpolar molecules pass through the membrane easily via passive transport.
True
What is endocytosis?
The process by which cells engulf substances from the outside environment.
What distinguishes exocytosis from endocytosis?
Exocytosis is the process of expelling substances from the cell.
Name a type of active transport mechanism.
Sodium-potassium pump
Which factor can change membrane permeability?
Presence of specific proteins or lipids
True or False: All cells use the same type of transport mechanisms.
False
What is the function of carrier proteins in facilitated diffusion?
They bind to specific substances and help them cross the membrane.
Multiple Choice: What is the primary driving force for passive transport? A) Energy from ATP B) Concentration gradient C) Ion channels D) Vesicles
B) Concentration gradient
What is passive diffusion?
The movement of molecules across a cell membrane without the need for energy.
What is facilitated diffusion?
The process of transporting molecules across a membrane via specific carrier proteins, without energy.
True or False: Passive diffusion requires energy input.
False
What type of molecules typically use passive diffusion?
Small, nonpolar molecules such as oxygen and carbon dioxide.
Fill in the blank: Facilitated diffusion uses __________ to help transport molecules.
carrier proteins or channel proteins
Which type of diffusion is faster: passive or facilitated?
Facilitated diffusion is generally faster due to the help of proteins.
What is the main driving force behind passive diffusion?
The concentration gradient.
True or False: Facilitated diffusion can occur against a concentration gradient.
False
What is an example of a molecule that undergoes facilitated diffusion?
Glucose.
Which type of diffusion is selective: passive or facilitated?
Facilitated diffusion is selective.
What happens to the rate of passive diffusion as temperature increases?
The rate of passive diffusion generally increases with temperature.
Fill in the blank: In facilitated diffusion, the direction of movement is always __________ the concentration gradient.
down
What role do membrane proteins play in facilitated diffusion?
They provide a pathway for specific molecules to cross the membrane.
True or False: Both passive and facilitated diffusion can reach a saturation point.
False; only facilitated diffusion can reach saturation.
What type of transport is passive diffusion classified as?
Passive transport.
Which type of diffusion would be affected by the presence of a membrane protein?
Facilitated diffusion.
What is the primary difference between passive and facilitated diffusion?
Passive diffusion does not require proteins, while facilitated diffusion does.
Fill in the blank: Passive diffusion occurs through the __________ of the phospholipid bilayer.
lipid
What is the significance of the concentration gradient in passive diffusion?
It drives the movement of molecules from high to low concentration.
True or False: Facilitated diffusion can transport ions.
True
What type of energy does facilitated diffusion utilize?
Facilitated diffusion does not utilize any energy; it is still a passive process.
What happens to molecules during passive diffusion?
They move freely across the membrane until equilibrium is reached.
Fill in the blank: Facilitated diffusion is essential for transporting __________ molecules.
polar or large
What happens to the rate of facilitated diffusion when all carrier proteins are occupied?
The rate of facilitated diffusion reaches a maximum and cannot increase further.
True or False: Both passive and facilitated diffusion occur in living cells.
True
What is one major advantage of facilitated diffusion over passive diffusion?
It allows for the transport of larger or polar molecules that cannot diffuse freely.
What is primary active transport?
The process of moving ions or molecules against their concentration gradient using energy directly from ATP.
What is secondary active transport?
The process of moving ions or molecules against their concentration gradient using the energy from the electrochemical gradient established by primary active transport.
True or False: Primary active transport requires ATP.
True
Fill in the blank: In primary active transport, ATP is hydrolyzed to ______.
ADP
Which ion is commonly involved in primary active transport through the Na+/K+ pump?
Sodium (Na+)
What is the main function of the Na+/K+ pump?
To maintain the electrochemical gradient by pumping sodium out of and potassium into the cell.
Multiple Choice: Which of the following is an example of secondary active transport? A) Na+/K+ pump B) Glucose transport C) Calcium ATPase
B) Glucose transport
True or False: Secondary active transport can be symport or antiport.
True
Define symport in the context of secondary active transport.
A transport mechanism where two substances are moved in the same direction across the membrane.
Define antiport in the context of secondary active transport.
A transport mechanism where two substances are moved in opposite directions across the membrane.
What is the role of glucose in the sodium-glucose cotransporter (SGLT)?
To be transported into the cell along with sodium ions, utilizing the sodium gradient established by primary active transport.
Fill in the blank: Secondary active transport relies on the _______ established by primary active transport.
electrochemical gradient
What condition can result from a malfunction of the Na+/K+ pump?
Cell swelling and potential cell lysis due to inability to maintain osmotic balance.
In which organ is the Na+/K+ pump particularly crucial for function?
The kidneys
Which type of transport is primarily responsible for nutrient uptake in intestinal epithelial cells?
Secondary active transport
True or False: Primary active transport can be influenced by the concentration gradient of the transported substance.
False
What does the term ‘electrogenic pump’ refer to?
A pump that generates a difference in charge across a membrane, such as the Na+/K+ pump.
Multiple Choice: Which of the following is NOT a characteristic of primary active transport? A) Direct use of ATP B) Movement against concentration gradient C) Involves symport mechanism
C) Involves symport mechanism
What is the clinical significance of understanding active transport mechanisms?
It helps in the development of drugs that target specific transport proteins in various diseases.
Fill in the blank: The proton pump in the stomach is an example of _______ active transport.
primary
True or False: Secondary active transport can occur without primary active transport.
False
What type of transport mechanism is utilized by the calcium-sodium exchanger?
Antiport secondary active transport
Which type of active transport is most energy-efficient?
Primary active transport
What is the primary energy source for secondary active transport?
The electrochemical gradient created by primary active transport.
Fill in the blank: In the renal tubules, sodium reabsorption is an example of _______ active transport.
primary
True or False: Both primary and secondary active transport can transport large molecules.
False
What is a uniporter?
A uniporter is a type of transport protein that moves a single type of molecule across a membrane in one direction.
True or False: A symporter transports two different molecules in the same direction across a membrane.
True
Fill in the blank: An antiporter moves two different molecules across a membrane in ________ directions.
opposite
Which type of transporter is primarily responsible for glucose and sodium ion transport?
Symporter
What is the main function of a uniporter?
To facilitate the passive transport of a specific molecule across a membrane.
True or False: Antiporters can use the energy from one molecule moving down its concentration gradient to move another molecule against its gradient.
True
What is the key difference between symporters and antiporters?
Symporters transport molecules in the same direction, while antiporters transport them in opposite directions.
Give an example of a molecule commonly transported by a uniporter.
Glucose
Multiple Choice: Which of the following is NOT a characteristic of a symporter? A) Moves two molecules B) Moves in the same direction C) Always requires ATP D) Can be powered by ion gradients.
C) Always requires ATP
True or False: All transport proteins are specific to the molecules they transport.
True
What role do antiporters play in cellular homeostasis?
They help maintain ion balance by exchanging ions or molecules across the membrane.
Fill in the blank: The transport process of a uniporter is typically ________ transport.
passive
Which transporter type would be involved in the exchange of sodium ions for potassium ions?
Antiporter
True or False: Symporters can be driven by the electrochemical gradient of one of the transported molecules.
True
What type of transport does a uniporter facilitate?
Facilitated diffusion
Multiple Choice: Which of the following statements is true about antiporters? A) They require energy input. B) They can only move ions. C) They move molecules in the same direction. D) They do not require any protein.
A) They require energy input.
What is the primary energy source for symporters?
The electrochemical gradient of an ion.
Fill in the blank: Uniporters are typically involved in the transport of ________ molecules.
small
True or False: All symporters are dependent on the concentration gradient of one of the solutes.
True
What happens to the concentration of a molecule when a symporter moves it into the cell?
It increases.
Fill in the blank: Antiporters are crucial for maintaining ________ balance in cells.
ion
What type of transport mechanism do uniporters utilize?
Passive transport
True or False: Symporters can transport solutes against their concentration gradient if coupled with a favorable gradient.
True
Name a common example of a symporter in human cells.
Sodium-glucose symporter
What is the main advantage of using antiporters in cellular transport?
They allow for the exchange of different ions or molecules, helping to regulate cellular conditions.
