Most small non polar molecules can diffuse across the membrane. Water is polar but diffuses across the cell through aquaporins. There are also proteins that actively transport substances across the cell membrane such as ions (ex.The Na/K pump). It can get a little confusing. I tried to be as simple as possible. I don't know if this is what you were looking for.
Water molecules freely diffuse across a semipermeable membrane.
selectively permeable
Large polar molecules such as proteins and glucose, as well as ions like sodium and potassium, will not diffuse directly across the lipid bilayer due to their size or charge. These molecules require specific transport proteins or channels to facilitate their movement across the membrane.
osmotically active
Gases diffuse most efficiently across a thin membrane or barrier. This is because a thin membrane allows for quicker movement of gas molecules from an area of high concentration to an area of low concentration.
Ions can't diffuse across membranes, they must used channels to transport across
Water molecules freely diffuse across a semipermeable membrane.
No, oxygen cannot directly diffuse across a cell membrane. Instead, it crosses the cell membrane with the help of specific transport proteins, such as aquaporins and oxygen channels. These proteins facilitate the movement of oxygen from areas of high concentration to low concentration.
Oxygen molecules diffuse across the membrane.
selectively permeable
selectively permeable
Large polar molecules such as proteins and glucose, as well as ions like sodium and potassium, will not diffuse directly across the lipid bilayer due to their size or charge. These molecules require specific transport proteins or channels to facilitate their movement across the membrane.
osmotically active
CO2, H2O, and O2 can all diffuse across a cell membrane. Also, small polar molecules (uncharged) and hydrocarbons easily diffuse across.
Gases diffuse most efficiently across a thin membrane or barrier. This is because a thin membrane allows for quicker movement of gas molecules from an area of high concentration to an area of low concentration.
Its too large
Nonpolar molecules like lipid-soluble substances (e.g., steroid hormones, oxygen, and carbon dioxide) are most likely to passively diffuse across the plasma membrane by dissolving in the lipid bilayer. This type of diffusion does not require a specific transport protein and can occur directly through the phospholipid bilayer due to the molecules' hydrophobic nature.