ap bio chapters 5 and 6 test questions

here you go, rats.

what is the plasma membrane?

a phospholipid bilayer with embedded proteins that surrounds both cells and organelles

what are the functions of the plasma membrane?

1) isolates cell cytoplasm from external environment

2) regulates exchange of essential substances between cytoplasm and external environment

3) communicates with other cells

4) identifies cells as belonging to a particular species and a particular member of that species

what is the fluid mosaic model?

developed by S.J. Singer and Garth L. Nicolson in 1972 to explain the structure of cell membranes

what are the four general types of membrane proteins based on function?

enzymes and recognition, receptor, and transport proteins

what are the two general types of membrane proteins based on position?

peripheral proteins and integral proteins

why is the plasma membrane described as “selectively or differentially permeable”?

it allows some things to cross the membrane but prevents others