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Questions and Answers
What type of molecules move through the lipid bilayer membrane in simple diffusion?
What type of molecules move through the lipid bilayer membrane in simple diffusion?
In active transport, what type of transport is linked to the hydrolysis of ATP or a high energy molecule?
In active transport, what type of transport is linked to the hydrolysis of ATP or a high energy molecule?
What drives secondary active transport across the membrane?
What drives secondary active transport across the membrane?
What is the main factor that determines the rate at which molecules diffuse across a membrane?
What is the main factor that determines the rate at which molecules diffuse across a membrane?
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Which molecule is more likely to undergo rapid diffusion across a membrane?
Which molecule is more likely to undergo rapid diffusion across a membrane?
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What happens to the concentration of a diffusing substance on either side of the membrane after simple diffusion?
What happens to the concentration of a diffusing substance on either side of the membrane after simple diffusion?
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What type of molecules is simple diffusion primarily feasible for?
What type of molecules is simple diffusion primarily feasible for?
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Which integral membrane proteins act as selective gates for certain molecules during facilitated diffusion?
Which integral membrane proteins act as selective gates for certain molecules during facilitated diffusion?
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What type of flow from high to low concentration is thermodynamically favorable during simple diffusion?
What type of flow from high to low concentration is thermodynamically favorable during simple diffusion?
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Which proteins assist in increasing the rate of transport via facilitated diffusion?
Which proteins assist in increasing the rate of transport via facilitated diffusion?
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What is the primary function of aquaporins in facilitated transport through pores?
What is the primary function of aquaporins in facilitated transport through pores?
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What structural feature in aquaporins prevents protons from entering the channel during water transport?
What structural feature in aquaporins prevents protons from entering the channel during water transport?
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Study Notes
Simple Diffusion
- Small, nonpolar molecules like oxygen, carbon dioxide, and lipids readily move through the lipid bilayer.
- The rate of diffusion is determined by the concentration gradient.
- The concentration of a diffusing substance will become equal on both sides of the membrane.
- Simple diffusion is a passive process driven by the concentration gradient, moving from a region of high concentration to low concentration.
Active Transport
- In active transport, the hydrolysis of ATP or a high energy molecule provides the energy for the movement of molecules across the membrane. This energy can be used to move molecules against their concentration gradient, from low to high concentration.
Secondary Active Transport
- Secondary active transport is driven by the electrochemical gradient established by primary active transport.
- The movement of one molecule down its concentration gradient provides the energy for the movement of another molecule against its concentration gradient.
Facilitated Diffusion
- Facilitated diffusion involves the assistance of integral membrane proteins called transport proteins.
- These proteins act as selective gates for specific molecules, allowing for the facilitated movement of larger or polar molecules that would otherwise struggle to cross the membrane.
- Aquaporins are a type of transport protein that facilitates the transport of water through a channel within the membrane.
- Aquaporins contain a narrow channel that excludes protons, ensuring only water molecules pass through.
- Facilitated diffusion can greatly increase the rate of transport for certain molecules.
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Description
Test your knowledge on the different types of cellular transport mechanisms. Learn about simple diffusion where small non-polar molecules move through the lipid bilayer, facilitated diffusion with the help of channel proteins, and active transport which moves substances against a concentration gradient using primary or secondary methods.
