Carbohydrates, proteins, and lipids are important molecules that make up the structure of the cell membrane. They help move materials into and out of the cell through the cell membrane In what way is the cell membrane like a security guard?

The cell membrane only alows certian materials to move through the membrane. Just like a security guard the membrane sorts through the good stuff and lets it past, but if someone or something bad comes along the security guard stops it. Just like the cell membrane.  

scientists have discovered that hiv does not cause aids by the virus's direct effect on the host's immune cells, but rather through the cells' lethal influence on one another. researchers from the gladstone institutes have revealed that hiv does not cause aids by the virus's

the animal that would be cutest if scaled down to the size of a cat? elephant