62 Questions
What is the primary function of cell transport?
To facilitate the movement of substances across the cell membrane
What type of substances can readily pass through a phospholipid bilayer?
Lipid-soluble substances
Which of the following is a characteristic of the cell membrane?
Semi-permeable barrier
What is the term for the movement of water molecules through the cell membrane?
Osmosis
What is the process of transporting substances out of the cell through the cell membrane?
Exocytosis
What is the role of membrane proteins in cell transport?
To provide an alternative pathway across the lipid bilayer
What is the characteristic of facilitated diffusion?
Rate of transport is directly proportional to the concentration of the diffusing substance
What is the main difference between simple diffusion and facilitated diffusion?
Simple diffusion occurs through the lipid bilayer, while facilitated diffusion occurs through specific proteins
What is the term for the minimum pressure required to stop osmosis?
Osmotic pressure
What is the primary function of aquaporins in the cell?
To facilitate the transport of water across the membrane
What is the characteristic of active transport?
Molecules move against their concentration gradient
What is the primary function of facilitated diffusion proteins?
To allow molecules to pass through the membrane
What is the main characteristic of ion channels?
They are highly selective and allow passage of specific ions or molecules
What is the purpose of aquaporins?
To allow water molecules to cross the membrane rapidly
What is the main difference between voltage-gated and ligand-gated channels?
Voltage-gated channels open in response to changes in voltage, while ligand-gated channels open in response to ligand binding
What is the energy source for primary active transport?
Breakdown of ATP or similar
What is the mechanism of secondary active transport?
The transport of molecules using the energy from the concentration gradient of the driving ion
What is the difference between symport and antiport?
Symport is the transport of two substances in the same direction, while antiport is the transport of two substances in opposite directions
What is the purpose of transcellular transport?
To transport substances across the cell from one ECF compartment to another
What is the mechanism of receptor-mediated endocytosis?
The binding of ligands to specific receptors on the cell surface
What is the difference between constitutive secretion and regulated secretion?
Constitutive secretion does not need a signal, while regulated secretion needs a signal
What is the primary function of the cell membrane as a barrier to substance movement?
To regulate the passage of substances into and out of the cell
Which type of transport does not require energy input to occur?
Passive transport
What determines the permeability of the cell membrane to certain substances?
The lipid solubility of the substance
What is the primary function of osmosis in cell transport?
To maintain the balance of water and solutes within the cell
What is the process by which cells take in external substances?
Endocytosis
Which type of transport does not require the cell to expend energy?
Passive transport
What is the primary function of carrier proteins in facilitated diffusion?
To bind to molecules or ions and facilitate their transport across the membrane
What determines the rate of simple diffusion across a membrane?
The lipid solubility of the substance
Which type of molecules can diffuse directly through the lipid bilayer?
Small hydrophobic molecules
What is the maximum rate of transport achieved by a carrier protein in facilitated diffusion?
Vmax
What is the primary function of carrier proteins in facilitated diffusion?
To bind to specific molecules and facilitate their passage across the membrane
What is the characteristic of ion channels that allows them to be selective?
Their ability to allow only specific ions to pass through
What is the function of aquaporins in the cell membrane?
To allow water molecules to cross the membrane more rapidly
What is the term for the simultaneous transport of two substances across a membrane in the same direction?
Symport
What is the primary function of voltage-gated channels?
To mediate the passage of ions across the plasma membrane in response to changes in voltage
What is the mechanism of transcellular transport?
Active transport through the cell membrane on one side and facilitated diffusion on the other
What is the function of receptor-mediated endocytosis?
To internalize specific molecules bound to receptors
What is the primary function of ion channels in the plasma membrane?
To mediate the passage of ions across the plasma membrane
What is the term for the process of transporting molecules out of the cell through the cell membrane using part of the membrane itself as a carrier?
Exocytosis
What is the primary function of constitutive secretion?
To incorporate proteins into the plasma membrane or extracellular matrix
What is the main function of the cell membrane in terms of substance movement?
To act as a semi-permeable barrier
What is the characteristic of substances that can readily pass through a phospholipid bilayer?
They are lipid-soluble
What is the purpose of the transport of substances across the cell membrane?
To maintain cellular homeostasis
What is the key difference between passive and active transport?
The energy requirement
What is the term for the movement of water molecules from an area of high concentration to an area of low concentration?
Osmosis
What is the primary function of membrane proteins in cell transport?
To act as channels or carriers for molecule transport
What determines the permeability of small hydrophobic molecules across the lipid bilayer?
The lipid solubility of the molecule
What is the characteristic of facilitated diffusion that distinguishes it from simple diffusion?
It is specific to certain molecules or ions
What is the role of aquaporins in the cell membrane?
To act as channels for the transport of water molecules
What is the term for the movement of water molecules from an area of high concentration to an area of low concentration?
Osmosis
What is the maximum rate of transport achieved by a carrier protein in facilitated diffusion?
Vmax
What is the primary mechanism of facilitated diffusion?
Passive transport with the help of carrier proteins
What is the characteristic of ion channels that allows them to be selective?
All of the above
What is the primary function of aquaporins?
To transport water molecules across the cell membrane
What is the primary function of voltage-gated channels?
To transmit information along the length of a neuron
What is the primary mechanism of receptor-mediated endocytosis?
The binding of a ligand to a specific receptor
What is the primary function of facilitated diffusion proteins?
To bind to specific molecules and undergo conformational changes
What is the primary function of secondary active transport?
To couple the movement of an ion down its electrochemical gradient to the uphill movement of another molecule
What is the primary function of ion channels in the plasma membrane?
To regulate the amount of ions in the cell
What is the primary function of transcellular transport?
To transport molecules from one ECF compartment to another
What is the primary function of constitutive secretion?
To transport molecules out of the cell without the need for a signal
Learn about the different types of cell transport, including passive and active transport, osmosis, endocytosis, and exocytosis. Understand how cells move molecules across their membranes and the processes involved.
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