Cell Membranes Flashcards
What do cell membranes on the cell surface do?
Barrier between cell and environment.
Control what enters and leaves the cell.
What do membranes within the cell do?
Barrier between organelle and cytoplasm.
Control what substances enter and leave the organelle.
What is compartmentalisation?
Organelles have membranes so that they contain different environmental conditions for separate reactions going on.
What is the structure of the cell membrane represented as?
Fluid Mosaic Model.
Explain why the membrane is described as;
Fluid?
Mosaic?
Phospholipids are constantly moving around so it is fluid.
Protein molecules are studded through the bilayer, like tiles in a mosaic.
What are the carbohydrate chains called that are attached to;
Proteins?
Lipids?
Glycoproteins.
Glycolipids.
What role do the phospholipids play in the cell membrane?
They act as a barrier to stop water-soluble substances entering.
What role does cholesterol play in the cell membrane?
Makes the membrane more rigid and adds stability.
What role do proteins play in the cell membrane?
Channel proteins- allow small/charged particles through.
Carrier proteins- transport molecules and ions across the membrane.
What role do glycoproteins/lipids play in the cell membrane?
They act as receptors for messenger molecules.
How do cells communicate with eachother to control processes?
By using messenger molecules (cell signalling).
What are membrane-bound receptors?
Proteins that act as receptors for messenger molecules.
Only receptors that have a specific ______ and messenger molecules that are _________ can bind together. Fill in the blanks.
Shapes.
Complementary.
What is a target cell?
A cell that responds to a particular messenger molecule.
How can drugs prevent a receptor from working?
They bind to the cell membrane receptors and block it.
