The Effect of Temperature on the plasma membrane Cell Proteins Cells">cell membrane of Beetroot Cells
To investigate whether temperature will damage and denature the plasma
cell surface membrane of beetroot cells.
In spite of their many differences in function and appearance, all
cells have a surrounding membrane (called the plasma membrane).
purpose of a cell membrane is to selectively control the movement of
substances into and out of the cell. The membrane is made of 40%
lipids, 0-10% carbohydrate and 50- 60% protein. Lipids tend to liquefy
at high temperatures causing ruptures in the plasma membrane. In
membranes there are intrinsic proteins that act as ‘carriers’ and
channels that assist with movement of molecules through the membrane
and extrinsic proteins that are embedded in the outer phospholipid
layer acting as receptors. Proteins inside the cytoplasm are found in
the ribosomes, rough endoplasmic reticulum and golgi vesicles.
Proteins in plants are more likely to withstand higher temperatures of
50 oC, but once proteins have denatured they are no longer able to
Cells are the basic living units of all plants and animals. The cell is the structural and functional unit of all living organisms. There are a wide variety of cell types, such as nerve, muscle, bone, fat, and blood cells. Each cell type has many characteristics, which are important to the normal function of the body as a whole. One of the important reasons for maintaining hemostasis is to keep ...
carry out there function. The membrane is an extremely thin partially
permeable 7.5 (nm) layer. Lipids belong to a group known as
triglycerides that are made by the combination of three fatty acid
molecules chemically linked to one glycerol molecule. All cells have a
surrounding membrane is some shape or form commonly called the plasma
membrane that contains a rich solution of water called the cytoplasm.
All Eukaryotic cells have nucleus’ that contain DNA, which holds the
genetic information and directs the cell’s activities.
Diffusion is the movement of molecules where they are in high
concentration to where they are in lower concentration, down a
concentration gradient. Energy for the movement comes from the kinetic
energy of the molecules themselves.
* White tile
* Cork borer
* Measuring Cylinder
* 2x boiling tube racks
* Boiling tubes
* Distilled water
I will be applying 7 different temperature ranges, 80 oC, 70oC, 60oC,
50oC, 40oC, 30 oC and 20oC on beetroot pieces to test if the increase
of temperature (the independent variable) does have an effect on the
release of pigment. The beetroot was cut into 5 cylinders using the
cork borer making sure the beetroot cylinders had roughly the same
diameter, length and surface area. The external dye (dependant
variable) was washed off and dried to maintain the accuracy of the
results. A beaker was heated using a Bunsen burner to and 80oC and
measured using a thermometer. The Bunsen burner was turned off and the
beaker allowed to settle. When the bath reached 80oC a piece of
beetroot was placed in the water for 1 minute (dependant variable).
When the minute had elapsed, the beetroot was removed and placed into
a test tube filled with 10cm3 of distilled water. Distilled water is a
... increase in temperature breaks bonds in the (mainly intrinsic) proteins in the cell membranes of the beetroot cells. The a membrane that holds the pigment, ... I gathered the necessary equipment: SS Thermostatically controlled water baths I ceSS ThermometerS S Stop watch Test tubes ... just before I placed the test tubes in the water baths/ Bunsen burners, and ensured that they submerged fully ...
clear liquid that ensures nothing should contaminate the beetroot and
it is possible to detect the slightest deviation in colour. Then, the
fluid in each of the test tubes will be analysed using a colorimeter.
The water bath was cooled to 70oC, 60oC etc repeating the procedure.
The fluid in each of the test tubes was analysed using a colorimeter
and the results were recorded.
I believe that more dye will be released from the beetroot as the
temperature increases. High temperatures may distort the active site
of the carrier affecting the shape of the fluid mosaic model membrane.
The increase of kinetic energy will speed up the diffusion rate of the
red pigment to a point then structural damage of the membrane and the
denatured proteins will increase the amount of red pigment escaping
out of the cells.
Graph showing release of pigment as temperature increases.
My graph shows a general trend that is, as the temperature increases
the amount of pigment released from the beetroot increases to.
My results increased steadily until the steep climb between the
temperature ranges of 60oC and 70oC. This is the point where most of
the proteins in the cells are being denatured allowing gaps to form
and the sudden rush of purple pigment to escape. After that point the
graph ‘tails’ off suggesting some of the denatured proteins are
blocking the holes created in the first place slowing down the release
of the purple pigment.
Basically, it is the input of kinetic energy due to the build up of
temperature that increases the rate of diffusion. This in turn will
damage and denature the plasma membrane causing substances contained
... will result in disrupting the membrane. From 40oC to 60oC, the graph is increasing steadily showing that the leaking of red pigments of the beetroot ... Title: The effect of temperature on beetroot’s cells membrane Objective: To use beetroot to investigate the effect of temperature on cell membranes andrelate the effect observed to ...
within the membrane to leak out. It is the breakdown of phospholipids
in the membrane, which cause gaps to appear allowing fluids (red
pigment in this case) to pass through. As the red pigment particles
move faster, they diffuse out of the membrane at a faster rate,
increasing more as the temperature increases.
The experiment went well but there were areas to the experiment that
could have been improved.
The beetroot cylinders were not always cut accurately, only estimated
which obviously alters the effect of the experiment. The temperature
(independent variable) in the water baths fluctuated, making it
extremely hard to get the desired temperature. The results could have
been made more reliable by repeating the experiment more than once and
by finding the mean value. After I had cut the beetroot pieces and
rinsed them to clean the red pigment leakage I found it hard not to
damage the membrane as I tried to dry the pieces off. I had to
complete the experiment in just over an hour, which I feel wasn’t long
enough. It is safe to say my results are accurate because other
students in my class had results that were similar to mine.
Finally, the beetroot gives a good representation of the theories
behind the plasma membrane and how it behaves but it does not give a
good representation of the whole eukaryotic group because their
behaviour may differ to others.