If the cell membrane becomes totally impermeable, water and dissolved gases, most notably oxygen, would no longer be able to enter or leave the cell. The cell membrane is usually permeable to a number of substances, mostly small, nonpolar molecules. Other polar or charged particles are transported across the membrane by special embedded protein structures, and so would not be directly affected by a change in membrane permeability.
The membrane permeability of animal cells and many other organisms is crucial to their survival. The inability to absorb oxygen or release carbon dioxide would quickly be lethal to such organisms. However, other organisms less dependent on oxygen-based metabolism would survive a while longer, although the condition would eventually kill them as well. One example is yeast, which takes in food molecules and generates energy from them without the need for oxygen.
The ability for water to pass through cell membranes is often as much a hindrance to the cell as it is a benefit. Many cells, particularly single-celled organisms, exist in environments with a different amount of solute in the water outside than they have inside. Thus, water tends to move into or out of the cell constantly, which the cell compensates for by expending energy.Learn More
The cytoplasm was discovered in 1835 by three biologists, George E Palade, Albert Claude and Christian de Duve. It was Robert Hooke who discovered the cell in 1831 and laid down the fundamentals for the study of the cell.Full Answer >
The National Science Foundation explains that viruses infect host cells by piercing the cells' outer membranes, digesting the walls and injecting virus DNA into the cells. While many viruses remain dormant under extreme conditions, such as freezing temperatures, they may come to life in the right conditions and enter another organism's cells.Full Answer >
The major difference between active and passive transport is that passive transport does not require the application of external energy, while active transport does. Both processes move molecules across the cell membrane, but passive transport always takes advantage of existing concentration gradients to allow a natural diffusion of molecules.Full Answer >
A sperm cell delivers its DNA to and fertilizes eggs, according to the National Center for Biotechnology Information. The BBC points out that this genetic material is contained in 23 chromosomes, which combine with the 23 chromosomes found in the female sex cell to make 23 pairs of chromosomes that contain all the genes for the new embryo.Full Answer >