25 Questions
What type of molecules can easily diffuse through the membrane?
Gases and hydrophobic molecules
What facilitates the diffusion of water through the membrane?
Aquaporins
What provides selectivity and facilitates transport across the membrane?
Transporters and channels
Which type of membrane protein forms tiny hydrophilic pores across the membrane to allow substances to pass via diffusion?
Channels
How do transporters shift small organic molecules or small inorganic ions from one side to another?
By changing shape and having binding sites for solutes
What determines exactly which solutes can pass in and out of a cell or organelle?
Each type of membrane's set of transports and channels
What represents the chemical potential caused by a barrier, and results in a unidirectional process?
Difference in concentration gradient
Which type of transport occurs down the concentration gradient without requiring energy?
Simple diffusion
Which type of transporter uses previously established gradients to transport molecules against the concentration gradient?
Secondary coupled transporters
What powers the active transport against the concentration gradient by binding or hydrolysing ATP?
ABC transporter
Which transporter only transports a single molecule?
Uniport
What is the result of the combination of electrical and chemical potentials?
Electrochemical gradient
What is used to establish and maintain ion gradients such as Na+ and K+?
Secondary coupled transporters
What causes the depolarization of the membrane potential by allowing the influx of Na+?
Gated ion channels
What percentage of total ATP is used by pumps like the sodium and potassium pump to establish and maintain gradients?
30-70%
Membrane permeability is highly efficient for large, charged molecules to pass through.
False
Aquaporins facilitate the diffusion of water through the membrane.
True
Transporters and channels are not selective and do not facilitate the transport of specific molecules.
False
Channels form hydrophobic pores across the membrane to allow substances to pass via diffusion.
False
Concentration gradient represents chemical potential caused by a barrier, and the process is bidirectional.
False
Passive transport always requires energy to move molecules across the membrane
False
F-type proton pumps use ATP as an energy source to transport molecules against the concentration gradient
False
Uniport transporters can move multiple molecules in different directions simultaneously
False
The combination of electrical and chemical potentials results in the electrochemical potential
True
The Nernst equation is used to calculate the electrical potential based on temperature, charge of ion, and concentrations
True
Test your knowledge on membrane permeability and transporters with this quiz. Learn about the diffusion of gases, hydrophobic molecules, small polar molecules, and water through membranes, as well as the role of transporters and channels in providing selectivity.
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