COMPLETE SOLUTIONS
cell membrane
all living cells in multicellular organisms have a surrounding
environment
the outer layer of your skin separates your body from its
cell membrane
(also known as the plasma membrane)
the cell membrane
separates the inner contents of a cell from its exterior environment.
cell membrane
provides a protective barrier around the cell and regulates which materials can pass in
or out.
phospholipids
The cell membrane consists of two adjacent layers of
interface
The lipid tails of one layer face the lipid tails of the other layer, meeting at
the____________of the two layers.
outward,
The phospholipid heads face
water in the intracellular fluid.
,Because the phosphate groups are polar and hydrophilic, they are attracted to
Intracellular fluid (ICF)
is the fluid interior of the cell.
Extracellular fluid (ECF)
is the fluid environment outside the enclosure of the cell membrane.
Interstitial fluid (IF)
is the term given to extracellular fluid not contained within blood vessels.
fluid
An important feature of the membrane is that it remains
lipids and proteins in the cell membrane
not rigidly locked in place
tail to tail
The phospholipid bilayer consists of two adjacent sheets of phospholipids, arranged
The hydrophobic tails associate with one another, forming
the_______________interior of the membrane.
The polar heads
contact the fluid inside and outside of the cell.
cell membrane,
The lipid bilayer forms the basis of the
integral proteins and peripheral protein
Two different types of proteins that are commonly associated with the cell membrane
are the
integral protein
,is a protein that is embedded in the membrane.
channel protein
an example of an integral protein that selectively allows particular materials, such as
certain ions, to pass into or out of the cell.
proteins and cholesterol, some with carbohydrate groups attached.
The cell membrane of the cell is a phospholipid bilayer containing many different
molecular components, including
cell recognition proteins
Another important group of integral proteins are
cell recognition proteins
serve to mark a cell's identity so that it can be recognized by other cells
recognition protein
A receptor is a type of__________that can selectively bind a specific molecule outside
the cell, and this binding induces a chemical reaction within the cell.
ligand
he specific molecule that binds to and activates a receptor
receptor and an ion channel
Some integral proteins serve dual roles as both a
dopamine
example of a receptor-ligand interaction is the receptors on nerve cells that bind
neurotransmitters, such as
ions
, When a dopamine molecule binds to a dopamine receptor protein, a channel within the
transmembrane protein opens to allow certain_______to flow into the cell.
Peripheral proteins
typically found on the inner or outer surface of the lipid bilayer but can also be attached
to the internal or external surface of an integral protein
Peripheral proteins
typically perform a specific function for the cell.
digestive enzymes
Some peripheral proteins on the surface of intestinal cells, for example, act
as_________________________________o break down nutrients to sizes that can
pass through the cells and into the bloodstream.
Cell membran
Has the ability to regulate the concentration of substances inside the cell
The membrane's lipid bilayer structure
provides the first level of control
nonpolar
the lipid tails of the membrane are
water-soluble materials—like glucose, amino acids, and electrolytes—
need some assistance to cross the membrane because they are repelled by the
hydrophobic tails of the phospholipid bilayer.
passive transport and Active transport
All substances that move through the membrane do so by one of two general methods.
What are they?