Ch. 7 - Membranes Flashcards
What purpose does cholesterol have in plasma membranes?
It acts as a temperature buffer, resisting changes in membrane fluidity.
What kind of proteins span the plasma membrane?
transmembrane proteins
What are six functions of membrane proteins?
- Transport
- Enzymatic activity
- Signal transduction
- Cell-cell recognition
- Intercellular joining
- Attachment to the cytoskeleton and ECM
Channel proteins which facilitate the transport of water.
aquaporins
What are the two kinds of transport proteins?
channel and carrier proteins
What is facilitated diffusion?
It is the passive diffusion of molecules with the aid of transport proteins.
This type of transport protein creates a membrane potential.
electrogenic pump
This mechanism involves an ATP-powered pump that drives the active transport of several other solutes.
cotransport
What are amphipathic molecules?
Molecules with both hydrophilic and hydrophobic regions.
What is the currently accepted design for plasma membranes?
fluid mosaic model
What is passive transport?
The passage of a substance through a biological membrane without the use of energy by the cell.
What is the regulation of water balance by animals in order to survive non-isotonic environments?
osmoregulation
