cell membranes Flashcards
what organelles in eukaryotic cells are surrounded by a cell membrane ?
endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, vacuoles, and plastids
what membranes surround cells ?
cell surface membranes and plasma membrane
what is the role of cell surface membranes ?
They are a barrier between the cell and its environment, controlling which substances enter and leave the cell.
why do cell surface membranes let some molecules through but not others ?
their partially permeable
what type of molecules do cell membranes let in ?
small non polar molecules ,small uncharged polar molecules
what are the methods of transport ?
diffusion ,osmosis and active transport
what do the cell membranes within cells do ?
divide the cell into different compartments — they act as a barrier between the organelle and the cytoplasm
what does the cell membrane surrounding mitochondrion do?
The substances needed for respiration (like enzymes) are kept together inside a mitochondrion by the membrane surrounding the mitochondrion
give an example of cell membranes within cells using the nuclear envelope ?
RNA leaves the nucleus via the nuclear membrane (also called the nuclear envelope).
DNA is too large to pass through the partially permeable membrane, so it remains in the nucleus.
