0:01
tenicity tenicity is the effect of
0:03
osmotic pressure gradient between
0:05
solutions separated by a semi-permeable
0:07
membrane when two solutions are
0:10
separated by a semi-permeable membrane
0:12
their relative solute concentrations
0:14
determine the direction of water flow
0:17
solution A has a higher concentration of
0:19
solutes compared to solution B water
0:22
molecules move from areas of lower
0:24
solute concentration to areas of higher
0:26
solute concentration in an attempt to
0:37
concentrations tenicity is a fundamental
0:40
concept in cell biology it regulates
0:43
cell volume affects cellular functions
0:45
and is critical for survival in
0:47
different environments understanding
0:49
tenicity is essential for explaining how
0:52
cells interact with their surrounding
0:55
environment hypotonic solutions have a
0:57
lower solute concentration than the
0:59
inside of cells in a hypotonic
1:02
environment the concentration of
1:04
dissolved substances outside the cell is
1:06
lower than inside the cell due to
1:08
osmosis water molecules move from the
1:11
area of lower solute concentration to
1:13
the area of higher solute concentration
1:15
into the cell let's see how animal cells
1:18
respond to hypotonic solutions in a
1:21
hypotonic environment animal cells
1:23
absorb water and swell without a rigid
1:26
cell wall continued water uptake causes
1:28
the cell to burst a process called lis
1:31
plant cells respond differently to
1:33
hypotonic solutions unlike animal cells
1:37
plant cells have a rigid cell wall when
1:40
water enters the cell in a hypotonic
1:42
environment the cell becomes turgid and
1:44
firm but doesn't burst let's take a
1:46
closer look at how water molecules move
1:48
across the cell membrane in a hypotonic
1:51
environment water molecules move through
1:54
specialized channels called aquaporins
1:57
or directly through the cell membrane
1:59
this movement is driven by the
2:00
concentration gradient with water
2:03
flowing from the hypotonic solution into
2:05
the cell this process continues until
2:07
equilibrium is reached or in the case of
2:10
animal cells until the cell membrane
2:13
ruptures unlike plant cells animal cells
2:16
lack a rigid cell wall and possess only
2:18
a flexible plasma membrane this makes
2:21
animal cells particularly vulnerable to
2:23
changes in environmental tenicity as
2:25
they can easily swell or shrink based on
2:29
movement in hypotonic environments water
2:33
flows into the cell causing it to swell
2:35
and potentially burst a process called
2:37
lis in isotonic environments there is no
2:40
net movement of water keeping the cell
2:42
in a normal and stable state in
2:45
hypertonic environments water flows out
2:47
of the cell causing it to shrink and
2:49
wrinkle a process called
2:52
cration animal cells utilize various
2:54
mechanisms to regulate tenity and
2:56
maintain proper cell volume the sodium
2:59
potassium pump actively transports
3:01
sodium ions out of the cell and
3:03
potassium ions in helping to maintain
3:06
ion balance ion channels allow specific
3:09
ions to move across the membrane based
3:10
on concentration gradients aquaporins
3:13
are specialized channels that allow
3:15
water molecules to move efficiently
3:19
membrane many animal cells are
3:22
specialized to function in environments
3:24
with different tenicity levels red blood
3:27
cells function in the isotonic
3:28
environment of blood plasma this balance
3:31
prevents them from swelling or shrinking
3:34
which would compromise their ability to
3:36
oxygen kidney tubule cells must function
3:39
in environments with varying tenicity as
3:42
they help concentrate urine they have
3:45
specialized membrane proteins to handle
3:47
these changing conditions marine animals
3:50
have cells adapted to hypertonic
3:52
saltwater environments with mechanisms
3:54
to prevent excessive water loss from
3:58
to summarize the key points about
4:14
cells that helps predict water movement
4:17
between solutions the mathematical
4:19
formula for calculating osmotic pressure
4:22
pi= let's break down what each variable
4:28
let's work through an example to
4:34
pressure sodium chloride solution at 25°
4:38
or 298 Kelvin we can calculate the
4:45
follows this osmotic pressure of 4.89 89
4:49
atmospheres drives water movement from
4:51
an area of lower concentration to higher
4:54
concentration across a semi-permeable
4:56
membrane the osmotic pressure relates
4:58
directly to tenicity solutions with
5:00
higher osmotic pressure are hypertonic
5:03
lower are hypotonic and equal pressures
5:05
are isotonic scientists and medical
5:08
professionals use osmotic pressure
5:10
calculations in various applications
5:12
these calculations are essential for
5:15
preparing cell culture media formulating
5:17
intravenous fluids and predicting how
5:20
cells will respond in different
