IONS!
If you were a protein destined to reach the plasma membrane and you were making your way through the Golgi when suddenly Golgi trafficking was blocked at the trans face, what would happen to you?
Small, nonpolar molecules such as oxygen and carbon dioxide would likely move through the lipid bilayer of a plasma membrane most rapidly due to their ability to dissolve in the hydrophobic core of the membrane.
During depolarization, sodium (Na) rushes into the neuron through Na channels (at the Nodes of Ranvier between the bundles of myelin "insulation"). Less Na in the extracellular fluid would mean there would be less to rush in. So, the neuron would not be depolarized as well. The resting membrane potential would be more positive on the inside.
A cell membrane is in every plant and animal and it lets in water, nutrients, and food to the cell. The membrane MUST be permeable because then it wouldn't of let the in water, nutrients, and food into the cell. If the membrane was stiff, the molecules of water, nutrients, and food would not be able to fit into the cell.
Small, non-polar molecules like oxygen and carbon dioxide would most easily pass through a cell membrane.
If you were a protein destined to reach the plasma membrane and you were making your way through the Golgi when suddenly Golgi trafficking was blocked at the trans face, what would happen to you?
ions and polar molecules
If a membrane is permeable to a substance, it means that there are gaps/holes/pores in the membrane large enough for that substance to pass through. Starch molecules are bigger that sugar molecules. So if the membrane is not permeable to sugars, the gaps/holes/pores will not be big enough for starch molecules to pass through either.
The cell would dissolve in water.
The cell would dissolve in water.
The cell would dissolve in water.
Globular proteins
The process by which large molecules enter a cell through pouches in the membrane is called endocytosis. During endocytosis, the cell membrane forms a pouch around the molecule, encloses it, and brings it into the cell as a vesicle. This allows the cell to take in larger molecules that would not be able to pass through the membrane on their own.
Small, nonpolar molecules such as oxygen and carbon dioxide would likely move through the lipid bilayer of a plasma membrane most rapidly due to their ability to dissolve in the hydrophobic core of the membrane.
Let trans-membrane transport of molecules be either passive, or facilitated, or active: the plasma [bi-lipid layer] membrane has the power to exclude molecules It selects from passage through the Membrane into the Cell's interior.
Molecules that do not pass through the cell membrane easily are typically large, polar, or charged, such as glucose, ions (like Na⁺ and K⁺), and proteins. In contrast, small, nonpolar molecules, such as oxygen and carbon dioxide, can easily diffuse through the lipid bilayer of the membrane. Additionally, water can pass through the membrane via specialized channels called aquaporins, though its small size would otherwise allow some diffusion.
During depolarization, sodium (Na) rushes into the neuron through Na channels (at the Nodes of Ranvier between the bundles of myelin "insulation"). Less Na in the extracellular fluid would mean there would be less to rush in. So, the neuron would not be depolarized as well. The resting membrane potential would be more positive on the inside.