Diffuses when water is needed inside of the cell. It usually happens by a hyper-tonic or hypo-tonic solution. Wherever there is a high and low.. water diffuses. Water usually diffuses high to low.
Water or any substance that has the ability to diffuse always diffuses from a high concentration to a low concentration. Through a cell memrane, it's the same thing. When we drink water, we gulp down a whole mouthfull. When it's time for it to diffuse, it goes into different cells. We drink in a high c. and the water goes in the cells in low concentration. Same thing when the water wants to come out. It goes to another place that needs it.
Water molecules freely diffuse across a semipermeable membrane.
selectively permeable
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.
osmotically active
Water molecules diffuse across the cell membrane during osmosis. Osmosis is the movement of water from an area of high concentration to an area of low concentration, across a semi-permeable membrane. This process helps maintain the balance of water inside and outside the cell.
Water molecules freely diffuse across a semipermeable membrane.
Ions can't diffuse across membranes, they must used channels to transport across
Oxygen molecules diffuse across the membrane.
Small, nonpolar molecules like oxygen, carbon dioxide, and ethanol can easily diffuse across the cell membrane due to their ability to pass through the lipid bilayer. Water can also diffuse across the membrane, albeit at a slower rate, through specialized channels called aquaporins.
selectively permeable
selectively permeable
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.
H2O CO2 O2 hope this helps
osmotically active
Osmosis. This is the movement of water molecules from an area of high water concentration to an area of low water concentration across a semi-permeable membrane.
Many gasses, water and lipids to name a few.
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.