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Non-polar molecules (such as fatty acids, steroid hormones and O2) pass freely through the cell membrane.
Small uncharged molecules (such as H2O) also pass freely, but are slower.
Large, polar molecules and ions (such as Na+ and K+) do not pass freely.
Macromolecules (such as proteins and polysaccharides) do not pass through the cell membrane.
Molecules and ions that cannot pass freely through the cell membrane rely on other means, such as protein transporters, to move in to the cell.
What else can I help you with?
What is cell membrane permeability?
It is the ability of the membrane to allow ions and/or particles to cross.
What receptor has a ligand that can cross the cell membrane that binds?
Intracellular
What molecules will move easily across the cell membrane: large proteins, starch, water, or DNA?
Water is the molecule that will move easily across the cell membrane. It can cross the membrane through special channels called aquaporins. Large proteins, starch, and DNA are too large to pass through the membrane without assistance.
What is the process where in the diffusion of water cross a cell membrane?
Osmosis
What are two structures that a material would have to cross to enter the cytoplasm of a plant cell?
In order to enter the cytoplasm of a plant cell, a material would have to cross the plasma membrane and then the cell wall. The plasma membrane regulates what enters and exits the cell, while the cell wall provides structural support and protection.
Can small hydrophobic molecules cross the cell membrane?
Yes, small hydrophobic molecules can cross the cell membrane.
Can nonpolar molecules cross the cell membrane?
Yes, nonpolar molecules can cross the cell membrane through simple diffusion.
Why can hydrophobic molecules cross the membrane?
Hydrophobic molecules can cross the cell membrane because the membrane is made up of a double layer of lipids, which are also hydrophobic. This allows hydrophobic molecules to pass through the membrane easily, while hydrophilic molecules have a harder time crossing.
What ions are positively charged and can cross back and forth across neuron and cell membrane?
There are two ions that can cross the cell membrane. The positively charged sodium and potassium ions can cross back and forth across the neuron cell membrane.
Why can small hydrophobic molecules cross the membrane?
Small hydrophobic molecules can cross the cell membrane easily because the membrane is made up of a lipid bilayer that repels water but allows non-polar molecules, like hydrophobic ones, to pass through.
Can polar molecules cross the cell membrane?
Yes, polar molecules can cross the cell membrane through facilitated diffusion or active transport.
What is cell membrane permeability?
It is the ability of the membrane to allow ions and/or particles to cross.
Can small polar molecules cross the cell membrane?
Yes, small polar molecules can cross the cell membrane through a process called passive diffusion.
What type of molecules can easily go through your cell membrane or are permeable to the cell membrane?
Substances with a hydrophillic-lipophillic balance are permeable through the cell membrane.
What receptor has a ligand that can cross the cell membrane that binds?
Intracellular
What molecules will move easily across the cell membrane: large proteins, starch, water, or DNA?
Water is the molecule that will move easily across the cell membrane. It can cross the membrane through special channels called aquaporins. Large proteins, starch, and DNA are too large to pass through the membrane without assistance.
What substance in the cell membrane keeps it from breaking too easily?
Cholesterol is a substance in the cell membrane that helps stabilize and strengthen the membrane, preventing it from breaking too easily. It helps maintain the fluidity and integrity of the cell membrane.
