Cell membranes Flashcards
(24 cards)
What is active transport?
The movement of particles from an area of low concentration to an area of high concentration using ATP.
What is bulk transport?
A form of active transport involving the movement of large molecules e.g. enzymes or hormones.
What role do carrier proteins play?
They play an important role in passive transport and active transport, often involving a change in the shape of the protein.
What are channel proteins?
Proteins that provide a hydrophilic channel allowing the passive movement of polar molecules and ions down a concentration gradient through membranes.
What is cytolysis?
The term used to describe the bursting of a cell.
What is diffusion?
The net movement of particles from an area of high concentration to an area of low concentration.
What is endocytosis?
The bulk transport of material into cells (phagocytosis for solids and pinocytosis for liquids).
What is exocytosis?
The bulk transport of material out of cells.
What are extrinsic proteins?
Proteins that are present on one side of the phospholipid bilayer.
What is facilitated diffusion?
Diffusion that occurs across a membrane through protein channels.
What is the fluid mosaic model?
A plasma membrane model where phospholipids are free to move within the layer relative to each other, with proteins embedded varying in shape, size, and position.
What are glycolipids?
Lipids with a carbohydrate chain attached.
What are glycoproteins?
Intrinsic proteins that have a carbohydrate chain attached.
What is hydrostatic pressure?
The pressure created by water in an enclosed system.
What are intrinsic proteins?
Integral/transmembrane proteins that are embedded through both layers of the membrane.
What are membrane proteins?
Proteins that are associated with the membrane.
What is osmosis?
The net movement of water molecules from an area of high water potential to an area of low water potential, across a partially permeable membrane.
What does partially permeable mean?
A membrane that allows some substances to cross but not others.
What is passive transport?
Transport that does not require energy from cellular respiration.
What is a phospholipid bilayer?
Membranes formed from a phospholipid bilayer where hydrophilic heads form both the inner and outer surface, sandwiching the fatty acid tails.
What is the plasma membrane?
The cell surface membrane which separates the cell from its external environment.
What are receptors?
Extrinsic glycoproteins that bind chemical signals, triggering a response by the cell.
What is turgor?
The pressure exerted against a cell wall.
What is water potential?
The pressure exerted by water molecules as they collide with a membrane or container.
