Communication || WELL-ENLIGHTENED
Types of Membrane Transport correct answers 1. *Passive transport* of small molecules that
doesn't require energy; it may involve transport proteins; with the gradient
2. *Active transport* of small molecules requires energy and a transport protein; against the
gradient
3. *Bulk transport* moves large molecules; includes *exocytosis* (large molecules are
secreted when a vesicle fuses with the plasma membrane) and *endocytosis* (large
molecules are taken in when the plasma membrane pinches inward, forming a vesicle)
Fluid mosaic model correct answers Structural model of the plasma membrane where
molecules are free to move sideways within a lipid bilayer; depicts the membrane as a mosaic
of protein molecules bobbing in a fluid bilayer of phospholipids
Passive transport correct answers -Requires NO energy,
-Movement of molecules from high to low concentration,
-Moves with the concentration gradient
Active transport correct answers 1. Energy-requiring process that moves material across a
cell membrane against a concentration difference
2. The energy is in the form of ATP hydrolysis
3. All proteins involved are *carrier proteins*
4. Enables cells to maintain solute concentrations that differ from the environment
Bulk transport correct answers The process by which large particles and macromolecules are
transported through plasma membranes; *exocytosis and endocytosis*
Exocytosis correct answers A process by which the contents of a cell vacuole are released to
the exterior through fusion of the vacuole membrane with the cell membrane.
Endocytosis correct answers A process in which a cell engulfs extracellular material through
an inward folding of its plasma membrane.
What determine the functions of a membrane? correct answers The proteins embedded in it;
every cell has a different composition of proteins
Peripheral proteins correct answers The proteins of a membrane that are not embedded in the
lipid bilayer; they are appendages loosely bound to the *surface of the membrane*
Integral proteins correct answers Penetrate the hydrophobic interior of the lipid bilayer