Page 1
CHAPTER 1 Cellular phagocytosis, to consume and destroy
bacteria and other foreign material.
Biology
B) Cellular Permeability:
Is the ability of the cell to allow passage of some
substances through the membrane, while not
permitting others to enter or exit.
Some substances have free passage in and out of the
cells, including enzymes, glucose, and electrolytes.
Enzymes are proteins that facilitate chemical
reactions in cells, while glucose is a sugar molecule
that provides energy. Electrolytes are chemicals that
are charged conductors when they are dissolved in
water. Failure of these exchange mechanisms can
lead to the development of disease.
Diffusion - is the movement of solutes—that
is, particles dissolved in a solvent—from an
area of higher concentration to an area of
lower concentration. Simple diffusion will
occur until the concentration gradient, which
is the difference in concentrations of
substances on either side of the membrane, is
equal on each side. Solution is made of a
solvent and solutes. Solvents dissolve solutes.
In the human body, the solvent is usually
water, and the solutes are particles such as
sodium, potassium, glucose, urea, and
oxygen.
Active Transport- is the movement of a
substance from an area of lower
concentration to an area of higher
concentration, against a concentration
gradient. This movement involves a carrier
molecule, like facilitated diffusion, but
energy, usually in the form of adenosine
triphosphate (ATP), is required because of
the effort necessary to go against the
gradient.
Endocytosis- is the process of bringing a
substance into the cell that is too large to go
by other mechanisms. Components of the
immune system use endocytosis, particularly
Page 1 of 14
, Page 2
Phagocytosis- or cell eating, occurs when this
process involves solid particles.
Pinocytosis- or cell drinking, takes place when
this process involves a liquid.
Osmosis- is the movement of water or any other
solvent across the cellular membrane from an area
of low solute concentration or high water to an
area of high solute concentration or low water.
Osmotic and hydrostatic pressure - help regulate
fluid balance in the body; an example can be
found in the functioning of the kidneys.
Oncotic pressure- is created by plasma proteins—
particularly albumin—and is similar to osmotic
pressure as higher pressure draws water in.
Hydrostatic pressure- is created by water pushing
against the cellular membrane, forcing the water
out, which is the opposite of osmotic pressure,
which, when higher, draws water in.
Osmolality -is the preferred term when referring to
fluids inside the body. Measured with osmometer.
Normal serum range is 282– 295.
Osmolarity is best used to describe fluids outside
the body.
Osmolal gap- is a difference between the
measured osmolality and the calculated
osmolality.
Exocytosis- is the release of materials (typically
large particles) from the cell onto the cell
membrane, usually with the
Page 2 of 14
CHAPTER 1 Cellular phagocytosis, to consume and destroy
bacteria and other foreign material.
Biology
B) Cellular Permeability:
Is the ability of the cell to allow passage of some
substances through the membrane, while not
permitting others to enter or exit.
Some substances have free passage in and out of the
cells, including enzymes, glucose, and electrolytes.
Enzymes are proteins that facilitate chemical
reactions in cells, while glucose is a sugar molecule
that provides energy. Electrolytes are chemicals that
are charged conductors when they are dissolved in
water. Failure of these exchange mechanisms can
lead to the development of disease.
Diffusion - is the movement of solutes—that
is, particles dissolved in a solvent—from an
area of higher concentration to an area of
lower concentration. Simple diffusion will
occur until the concentration gradient, which
is the difference in concentrations of
substances on either side of the membrane, is
equal on each side. Solution is made of a
solvent and solutes. Solvents dissolve solutes.
In the human body, the solvent is usually
water, and the solutes are particles such as
sodium, potassium, glucose, urea, and
oxygen.
Active Transport- is the movement of a
substance from an area of lower
concentration to an area of higher
concentration, against a concentration
gradient. This movement involves a carrier
molecule, like facilitated diffusion, but
energy, usually in the form of adenosine
triphosphate (ATP), is required because of
the effort necessary to go against the
gradient.
Endocytosis- is the process of bringing a
substance into the cell that is too large to go
by other mechanisms. Components of the
immune system use endocytosis, particularly
Page 1 of 14
, Page 2
Phagocytosis- or cell eating, occurs when this
process involves solid particles.
Pinocytosis- or cell drinking, takes place when
this process involves a liquid.
Osmosis- is the movement of water or any other
solvent across the cellular membrane from an area
of low solute concentration or high water to an
area of high solute concentration or low water.
Osmotic and hydrostatic pressure - help regulate
fluid balance in the body; an example can be
found in the functioning of the kidneys.
Oncotic pressure- is created by plasma proteins—
particularly albumin—and is similar to osmotic
pressure as higher pressure draws water in.
Hydrostatic pressure- is created by water pushing
against the cellular membrane, forcing the water
out, which is the opposite of osmotic pressure,
which, when higher, draws water in.
Osmolality -is the preferred term when referring to
fluids inside the body. Measured with osmometer.
Normal serum range is 282– 295.
Osmolarity is best used to describe fluids outside
the body.
Osmolal gap- is a difference between the
measured osmolality and the calculated
osmolality.
Exocytosis- is the release of materials (typically
large particles) from the cell onto the cell
membrane, usually with the
Page 2 of 14
