Download Afternoon Tea With a Cell

Name:_____________________
Afternoon tea with a cell
Biology is the study of living things. All living
things are made of smaller building blocks called
cells. But what are cells made of? Today you will
become familiar with some of the smaller
structures that make up cells. You will construct
models of some of the structures/organelles found
in plant cells, think about how each model
represents its real life structure/organelle and find
out about the role of each of these structures
within a cell. Then, if you would like to, you can
consume the edible organelles, while you review
with your partner what you have learnt.
What to do:
In this activity you will work with a partner to make model components for your shared plant cell.
You will be given a square foil tray to hold the components. It will represent the cell wall. You will
rotate, as directed, to each site around the room and follow the instructions given to construct
various cell structures. You will label each structure, add it to the cell and fill out its relevant
information in this booklet. As a class we will examine the model cells and discuss weaknesses of
the model. (Note: the 3 dimensional nature of the cell will not be shown in this model).
1)
a. Cell wall
Structure
In plant cells
composed of
_____________
Function
Image
The foil tray is like the
cell wall because:
Permeable to
most molecules
b. Cell membrane (plasma membrane)
Structure
Function
Image
The crepe paper Is
like the cell
membrane because:
c. Vacuole
Structure
Membrane bound
organelle that may
contain food, enzymes
or fluid
In plants the vacuole is
Function
Image
The jelly cup/water
balloon is like a
vacuole because:
d. Nucleus
Structure
Function
Image
Constuction:
Ferrer Roche is like a
Nucleus because:
It is lacking as a
nucleus because:
e. Mitochondrion(pl mitochondria)
Structure
Function
Image
Constuction:
Iced jelly bean is like a
mitochondria
because:
f. Chloroplast
Structure
Function
Image
Constuction:
Foil contained of
stacked smarties is
like a chloroplast
because:
g. Golgi body
Structure
Function
Image
We made lolly snakes
look like a golgi body
by:
Image
The bread has been
made to resemble
rough ER by
h. Rough Endoplasmic reticulum(R.E.R
Structure
Function
i. Ribosome
Structure
Function
Image
A hundred and
thousand is like a
ribosome in a cell
because:
j. Lysosome(found in some plant cells but this is controversial)
Structure
Small membrane
bound structure
containing strong
digestive enzymes
Function
Image
enzymes
Other organelles that we are not including in our model
A chocolate coated
sultana is like a
lysosome in a cell as:
Smooth Endoplasmic reticulum(smooth ER)
Structure
Function
Image
Suggest how this could
have been successfully
modelled?
Function
Image
Suggest how this could
have been successfully
modelled?
Function
Image
Suggest how this could
have been successfully
modelled?
Cytosol
Structure
Centrioles
Structure
We have missed out a few other structures which we will consider later on; cytoskeleton, cilia and
flagella.
2) Examine the diagrams of a photosynthetic plant cell shown.
a) List weaknesses of the model produced and suggest improvments/alternative materials for
each of these.
b)(i) Which structures are found in plant cells but NOT animal cells?
(ii) Of these structures are found in all plant cells ?
3) Write down at least two questions that you have thought of whilst completing this activity.
Investigate to find the answer to these.
CELL WALL
Colour in the cell wall on the image
in your table. It is NOT the black
line but the white section between
the black lines.
Cell wall
Modelling this structure
The foil tray is representing the cell wall. You don’t need to do
anything to it. Think about the struction and function of a real cell wall
and consider how the foil tray is like a real cell wall in the context of
our model. It is chemically very different. The tray is made from
metal whilst the cell wall of a plant cell is composed of cellulose.
Structure
 In plant cells the cell wall is composed of a carbohydrate called
cellulose(fibre)
 Extremely permeable - ie allows most molecules to pass through
Function
 provides structural support
 limits the expansion of the cell
Occurance
All plant cells and no animal cells
(also some protist cells, all fungal and bacterial cells (although different
chemistry to plant cell cell walls
CELL MEMBRANE
Modelling this structure
A square of white crepe paper is provided to
model the cell membrane. Cut the paper as
required to line the foil tray. I suggesting cutting a square from each
corner of the crepe paper provided to enable a better fit. Use the
skewer to make perforations in the crepe paper and line the foil tray
with the tissue paper. Use tape to secure if necessary.
Structure
 A double layer of phospholipids embedded with protein molecules.
(phospholipid bilayer)
 Some membrane proteins form pores or channels which allow some
select particles to cross the membrane
Function
 To enclose cytoplasm
 To control what enters and leaves the cell
 There are other important roles as well that we will explore later.
These include having a role cell communication and cell
recognition.
Occurance
All cells! Yes; plant cells have a cell wall but in addition to this they also
have a cell membrane. The cell membrane pushes hard up against the
wall and it often not distinguishable.
VACUOLE
In plant cells the
vacuole is large
and permanent
The membrane around the vacuole
is called the tonoplast
In animals cells
vacuoles are small
and temporary
Modelling this structure
You can use a fruit jelly cups to model the vacuole or if you would
rather you can fill a water balloon with water, tie it up and pop that in
instead.
Structure
Membrane enclosed comparment in a cell. Enclosing membrane is
called the tonoplast
Function
 Storage
 Structural support inplant cells; assists in a cell becoming turgid.
Occurance
Most cells at some point(not bacterial cells) but vary in size and
permanency . All plant cells have a large permanent vacuole.
Nucleus
Nucleus
Nuclear
membrane
nucleolus
Chromatin
(DNA and
protein)
DNA
chromosome
Modelling this structure
Unwrap the Ferrero Roche. Use a sharp knife to
cut through the centre of the chocolate, exposing
a cross section. Examine the cross section. What
might the hazel nut inside represent?
.
Structure
 Relatively large organelle;seen with light
microscope
 Surrounded bya double membrane
 contains chromosomes
Function
 controls cellular activity
Occurance
Found in plant, animal, protist and fungal cells.(eukaryotic cells)
Not found in bacteria(prokaryotic cells)
MITOCHONDRIA
Inner membrane is highly folded
Modelling this structure
In our model we will show sectioned mitochondria. Cut a jelly bean in
half lengthways. The hard sugar coating represents the outer
membrane. Use icing tubes to apply icing to represent the highly
folded internal membrane.
Each person should use one jelly bean and ice each side.
Structure
 cigar shaped or circular in cross section(depending on the
section)
 consists of a double membrane (outer membrane and highly
folded inner membrane)
 contains its own DNA and ribosomes
Function
 Produces usable energy(ATP) by the process of cellular
respiration
Occurance
Not found in bacterial cells but present in plant cells, animal cells, fungal
cells and protists. (a few cell types do loose mitochondria during their
development)
CHOROLOPLAST
Modelling this structure
Use a layered rectangle of foil to form a small, boat shaped container.
Use sticky tape to secure. Into this container place three stacks of 3
green smarties. These represent the grana(stacks of thylakoids)
side view
from above
Structure
 surrounded by a double membrane
 contains its own DNA and ribosomes
 green in colour due to the pigment chlorophyll which traps light
energy
Function
 site of photosynthesis(produces glucose)
Occurance
Some plant cells, some protist cells
GOLGI BODY
(and vesicles)
Modelling this structure
Cut a snake lollly into 3 of 4 pieces. Cut the head off and cut it into
small circles. Use toothpicks to secure the snake pieces to resemble
the membraneous stacks of the golgi body and place the small round
head peices around the edge to represent vesicles.
Structure
 stacks of short membranous disks(usually 5-8 disks); often
surrounded by vesicles
Function
 Stores and modifies proteins and packages them into vesicles for
transport around the cell or export from the cell
Occurance
Plant, animal, protist and fungal cells(eukaryotic cells)
NOT bacterial cells (prokaryotic cells)
ROUGH ENDROPLASMIC RETICULUM
Modelling this structure
Butter a piece of bread and sprinkle some hundreds and thousands
onto it.(these represent ribosomes embedded in the membrane of the
ER. Cut bread into strips and arrange these to resemble the ER. Use
toothpicks to secure. Place in model so it is in contact with the
nucleus. There is enough bread to use up to 1 ½ slices per PAIR if
needed.
Structure
 a network of intracellular membranes with its surface covered in
ribosomes
Function
 transport proteins from ribosomes to the smooth endoplasmic
reticulum
Occurance
Plant and animal cells
(also protist cells and fungal cells)
RIBOSOME
Two subunits
Messenger RNA
Modelling this structure
The hundreds and thousands on the bread represent ribosomes.
These can also be free floating in the cytosol, so sprinkle a few into
the cell.
Structure
 smallest organelle (only seen with electron microscope)
 Can be freely suspended in cytosol or attached to ER
 Compose of two units but is NOT membrane bound
Function
 site of protein synthesis
Occurance
ALL cells
LYSOSOME
STRONG DIGESTIVE ENZYMES
Modelling this structure
The chocolate coated sultana is representing the lysosomes. You
don’t need to do anything to it.
Structure
 membrane bound vesicles that contain digestive enzymes
Function
 digest foreign substances, materials no longer needed in the cell
and play a role in organised cell death(apoptosis)
Occurance
Most animal cells and some plant (although there is some debate about
this)
SMOOTH ER
Structure
 a network of intracellular membranes that do not have embedded
ribosomes
Function
 transport proteins from rough endoplasmic reticulum to Golgi body
 involved in the synthesis of lipids (fats and phospholipids) and
steroids
Occurance
Found in plant, animal, protist and fungi cells. Not found in bacteria
Cytosol
11: cytosol
Structure
 the fuild inside the cell in which the cell structures are supended.
 mainly composed of water, and contains ions, salts, enzymes, food
molecules
Function
 Many cell processes occur here
 Suspension of oranelles
Occurance
Found in all living cells
Materials per class (24 students)
12 scissors
12 foil trays
12 square sheets of crepe paper(to fit foil tray)
12 skewers
Site 1: nucleus
12 x ferrer Roche or lidnt balls(if a nut alergy in
class)
1 x sharp knife
1 x plate
Site 2 Rough ER
Loaf of sandwich bread
Spreadable butter or similar
Hundreds and thousands
2 x bread and butter knife
1 x large board
2 x plates
1 sharp knife
50 tooth picks
Site 3 ribosomes
Site 4 mitochondria
Small container of Hundreds and thousands
25 jelly beans
2 x icing writing tubes
Cutting board
Sharp knife
Foil
Tape
Green smarties
Site 5 Chloroplast
Site 6 Golgi body
Site 7 lysosomes
Site 8 Vacuole
25 snakes
2 x sharp knives
2 x chopping board
25 x toothpicks
25 x chocolate coated sultanas
25 x jelly cups
25 x water balloons