Ch4/5
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
endocytosis.
Examine the cells below. Cells with a higher concentration of ions than the surrounding medium tend to ________.
expand
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion.
When mixed with water, phospholipids spontaneously form membranes because they ______.
have hydrophilic phosphate groups that are attracted to water and hydrophobic fatty acid tails that avoid water
A plant cell placed in a(n) ________ solution will lose water and plasmolyze.
hypertonic
This cell is in a(n) _____ solution
hypertonic
You know that this cell is in a(n) _____ solution because the cell _____.
hypotonic ... swelled
Endocytosis moves materials _____ a cell via _____.
into ... membranous vesicles
In active transport,
molecules move across the plasma membrane against their concentration gradient.
What name is given to the process by which water crosses a selectively permeable membrane?
osmosis
Facilitated diffusion is a type of _____.
passive transport
A white blood cell engulfing a bacterium is an example of _____.
phagocytosis
________ are the major lipids of plasma membranes
phospholipids
Which of the following is a function of the plasma membrane?
regulate the traffic of chemicals in and out of the cell
Structure B is a _____.
transport protein
Which of the following are the two main components of cellular membranes?
proteins and phospholipids
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
active transport
There is a net diffusion of water out of an animal cell when it is placed in a(n) ________ solution.
hypertonic
You know that this cell is in a(n) _____ solution because it _____.
hypertonic solution ... lost water
An animal cell placed in a(n) ________ solution will gain water, swell, and possibly burst.
hypotonic
The ideal osmotic environment for a plant cell is a(n) ________environment.
hypotonic
The ideal osmotic environment for an animal cell is a(n) ________environment.
isotonic
When molecules move down their concentration gradient, they move from where they are __________ to where they are __________
more and less concentrated
Diffusion across a biological membrane that does not use energy is called _________
passive transport
Water crosses the plasma membrane
through facilitated diffusion or diffusion
