EVERYDAY SCIENCE

Detailed explanation-1: -Explanation: Small and simple molecules like water, H2O, can pass through the cell membrane easily as it is partially permeable. The cell membrane can filter out unimportant molecules that the cell does not need to use, and also only lets small molecules pass through.

Detailed explanation-2: -In contrast to carrier proteins, channel proteins simply form open pores in the membrane, allowing small molecules of the appropriate size and charge to pass freely through the lipid bilayer.

Detailed explanation-3: -The membrane is selectively permeable because substances do not cross it indiscriminately. Some molecules, such as hydrocarbons and oxygen can cross the membrane. Many large molecules (such as glucose and other sugars) cannot. Water can pass through between the lipids.

Detailed explanation-4: -The cell membrane is semipermeable (or selectively permeable). It is made of a phospholipid bilayer, along with other various lipids, proteins, and carbohydrates.

Detailed explanation-5: -They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot. Small hydrophobic molecules and gases like oxygen and carbon dioxide cross membranes rapidly. Small polar molecules, such as water and ethanol, can also pass through membranes, but they do so more slowly.