Transcript Turgor pressure File - Galena Park ISD Moodle

CELLS: Plants
 TEKS 7.13B- Describe and relate responses in organisms that may
result from internal stimuli such as wilting in plants …that allow them to
maintain balance
TEKS 7.7C- Demonstrate and illustrate forces that affect motion in
everyday life such as emergence of seedlings, turgor pressure, and
geotropism
PLANT CELLS: Vacuole
• A vacuole is a membrane-bound
sac found in plant and animal cells.
• Vacuoles tend to be large in plant
cells and play several roles: storing
nutrients and waste products,
helping increase cell size during
growth, and even acting much like
lysosomes of animal cells.
• The plant cell vacuole also regulates
turgor pressure in the cell.
• Water collects in cell vacuoles,
pressing outward against the cell
wall and producing rigidity (stiffness)
in the plant.
• Without sufficient water, turgor
pressure drops and the plant wilts
(droops)
ANIMATION
• http://www.kscience.co.uk/animations/turgor.htm
Reviving Celery
Materials:
• wilted stalk of celery
• glass of water
• blue food coloring
• knife
Procedure:
• Slice off a large piece
of the bottom of the
stalk of celery. Put
five drops of blue food
coloring in the glass
of water. Place the
celery in the water
and let it stand
overnight.
What’s your hypothesis?
• Record your
observations in their
science journals, and
make a prediction
about what you think
will happen in a few
days.
What happened?
 Slicing off the bottom off of the celery
stalk made sure that none of the celery
cells were not closed off of dried out.
 The blue water then entered in the
water-conducting tubes called
xylem. These tubes follow the whole
length of the stalk of the celery.
 Water leaves the xylem tubes and
enters the cells up and down the celery
stalk.
 When you slightly bend a plant, you
notice that it stands up straight again
after you let go. This is because every
single plant cell is full of water. The
water makes each cell firm, and all the
cells combined give the plant a rigid
feeling.
 A plant wilts when it doesn't get enough
water. The cells lose water and
become limp. Then, the plant droops.
 The pressure of the water inside the
vacuoles of the plant is called turgor
pressure
The picture shows a turgor pressure demonstration
using celery. Place the pictures of the celery in
order of least amount of pressure to the greatest
amount of pressure.
A)
B)
C)
D)
Q, R, S, T
S, R, Q, T
Q, R, T, S
S, T, Q, R