Download Title: Turgor Pressure in Plants - Flipped Out Science with Mrs

Title:
Turgor Pressure in Plants
Write in your journal
Title on one side
Lab here: pre-title now (will glue in
after graded)
Watch the video:
https://www.youtube.com/watch?v=fhsurzE_-J0
In your journal- answer below:
1. What happened to the celery
when water was added?
2. Why? Be as specific as you can.
Recall what you know about plant
cells, cell walls/membranes and
the purpose of vacuoles.

All systems, including ecosystems and the human
body, need a way of maintaining equilibrium, or
balance.

When a system is in equilibrium, it is stable, and all
its parts function smoothly.

All organisms, whether they are humans, bacteria, or
plants, must maintain internal equilibrium no matter
what happens in their environment.

The process by which the body’s internal environment
is kept stable in spite of changes in the external
environment is called homeostasis.
Equilibrium

Like all organisms, plants need to
maintain water equilibrium in spite of
changing conditions.

Many plants obtain water through their
roots (and the cells in those roots).

The cells in a plant’s roots, like all cells,
are bound by a thin, flexible structure
called the cell membrane.
Equilibrium in Plants
Osmosis

Water enters through the cell membrane.
Moving from an area of high
concentration to low concentration.

The structure of plant cells contributes to
a plant’s ability to maintain water balance.

The cell wall is rigid, located outside the
cell membrane

Since cell walls are rigid, they limit the
ability of plant cells to expand.

As water molecules move into a plant cell,
the expanding cell membrane presses
against the rigid cell wall.
 The
pressure of water against
the cell wall of a plant cell is
called turgor pressure.

Animation of Turgor Pressure in a cell
What is Turgor Pressure?

Turgor pressure helps give shape and
firmness to plant stems and leaves.

If the environment outside a plant cell is
dry, more water leaves the plant cell than
enters it.

As a result, turgor pressure inside cells is
reduced.

The cell membranes no longer press
against the cell walls.

The plant then loses its stiffness and wilts.
Turgor Pressure
Read Instructions
 What would be a good hypothesis?

Turgor Pressure Lab
Each section has procedures. Read them
carefully. Do not begin work if you do not
understand them – ask for help!
 At each station all of the supplies are
labelled, make sure you are using the
correct solution!

Demonstration of procedure:
Procedure:
Place a thin sliver of moist
onion tissue (red colored) onto
a glass slide.
Put a drop of water on the slide
and drop a cover slip. Record
your observations.
Now touch the edge of the slide
with a dropper filled with salt
solution. Allow salty water to
draw across the cover slip.
Record the time and record
your observations.
Lab Completion
Lab MUST be clean before you are allowed
to sit down
 Once you are approved to go back to your
seat, finish drawings by adding color
 Lab is not complete until the conclusion
questions are answered.
 If not done in class, they are homework
and due next class.

No salt vs. high salt