Download Big Plant Cell Foldable – Answer Key

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Big Plant Cell Foldable – Answer Key
What you expect your students to produce will depend on their grade level and their academic level.
The detailed information provided in the answer key is to give you a more thorough understanding
about this topic. You most likely do not require your students to know all the details, so for your ease
of use, highlight which details you would like students to know and use these to guide your lessons.
Highlight the details you would like them to know. Note: Structures with an asterisk * next to it are
not found in animal cells.
Structure
Function
1. *plasmodesma  Plasmodesmata (plural) are channels that exist between neighbouring plant
cells that allow substances to be transported between them. This enables the
exchange of materials between cells as well as cell-to-cell communication.
2. *amyloplast
3. peroxisome
4. Golgi body
5. Golgi vesicles
6. tonoplast
7. *central
vacuole
 Amyloplasts are non-pigmented plastids (membrane bound) that function to
synthesize starch, (through the polymerization of glucose formed during
photosynthesis in chloroplasts) as well as store starch.
 Peroxisomes are membrane bound organelles that contain enzymes that are
responsible for many metabolic reactions. One main type of metabolic
reaction is the catabolism (breakdown) of fatty acids through beta-oxidation.
The products of this breakdown can be converted into carbohydrates. This
function is especially important to plant germination when the stored fats in a
seed are converted into carbohydrates to provide the energy needed for kickstarting and maintaining germination.
 This is a group of membrane sacs in the shape of a stack of pancakes. They
work closely with the RER to process and package molecules (mostly proteins)
and then ship these molecules throughout the cell and outside of the cell
through the use of vesicles.
 These are small membrane bound organelles that originate from the Golgi
when the membrane of the Golgi pinches off. Vesicles contain and transport
substances (enzymes and other molecules that were synthesized and moved
through the ER to the Golgi) throughout the cell.
 The semi-permeable membrane surrounding a vacuole. It helps regulate what
goes into and out of the vacuole.
 The large vacuole found in the center of most plant cells. Often it will be the
largest organelle and push all the other organelles to the periphery of the cell.
 It functions to store water as well as ions and waste.
 The water storage function of the vacuole provides a turgor pressure that
pushes against the inside wall of the cell, thus giving the cell its shape and
rigidity. Dehydrated cells lose turgor pressure and appear deflated.
8. mitochondrion  Often considered the “power-house” of the cell, mitochondria are responsible
for creating cellular energy through the synthesis of ATP (adenosine
triphosphate). They do this through a process called aerobic cellular
respiration whose balanced chemical equation is: C6H12O6 + 6O2  6H2O +
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6CO2
 They have a double membrane, a singular circular strand of DNA, their own
ribosomes and they can self-replicate.
 Endosymbiotic theory (or symbiogenesis) proposes that mitochondria in
eukaryotes have prokaryotic origins. They arose when free-living
proteobacteria were engulfed and survived inside of other cells to form
endosymbionts around 1.5 million years ago.
9. *chloroplast
10. cytoskeleton
11. nuclear pores
12. nuclear
membrane /
envelope
13. DNA in
nucleoplasm
14. nucleolus
 Chloroplasts perform photosynthesis which creates food for plants and other
photoautotrophic eukaryotes. They do this using a green pigment called
chlorophyll which is capable of capturing light energy. The balanced chemical
equation for photosynthesis is: 6H2O + 6CO2  C6H12O6 + 6O2
 Like mitochondria they have a double membrane, but within chloroplasts
there is an additional membrane system (thylakoid membrane system) which
contains the chlorophyll for capturing the light energy. Like mitochondria,
chloroplasts also have their own singular circular strand of DNA, their own
ribosomes and they can also self-replicate.
 Like mitochondria, endosymbiotic theory (or symbiogenesis) proposes that
mitochondria in eukaryotes have prokaryotic origins. They arose when freeliving cyanobacteria were engulfed and survived inside of other cells to form
endosymbionts around 1.5 million years ago.
 This is a network of fibrous and interconnected proteins that functions as a
cellular scaffold to position, secure and move organelles around within the
cell. It also helps to give a cell it shape and provides structural supports for
the cytoplasm. The cytoskeleton is made of three types of components:
microfilaments, microtubules and intermediate filaments.
 These are channels through the nuclear membrane that allow certain
substances to be transported between the nucleoplasm (the contents within
the nuclear membrane) and the cytoplasm outside of the nucleus.
 They are large enough to allow mRNA and ribosomal units to leave the nucleus
(while keeping the longer DNA strands inside) and they also allow important
proteins and molecules from the cytoplasm to enter the nucleus
 This is the semipermeable double membrane (it has two lipid bilayers instead
of one layer like that found in the cell membrane) that surrounds and protects
the nuclear contents. Its selectively permeable nature also controls the traffic
of substances across the nuclear membrane. It contains nuclear pores.
 The DNA within the nucleus is found coiled around proteins called histones.
Together the proteins + DNA form long strands called chromatin (which when
condensed form chromosomes). The DNA itself contains some important
sections called genes, these code for all the genetic traits of each organism.
However, much of the DNA is non-coding, though these sections can still serve
regulatory roles that control gene expression.
 This dense section within the nucleus serves as the center for ribosome
synthesis and assembly. It forms the protein subunits needed to make the
ribosomes as well as the rRNA (ribosomal RNA) that is incorporated into these
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subunits.
15. nucleus
16. rough
endoplasmic
reticulum
(RER)
 This is often called the “control center” of the cell. It is made of a
semipermeable double membrane system (nuclear membrane) which
surrounds a nucleoplasm (nuclear contents). The following are its functions:
1) store and protect the DNA (genetic information) within it, 2) it is the site of
ribosomal assembly (within nucleolus) and 3) RNA synthesis.
 RER is called “rough” because it has ribosomes embedded on its membrane
surface. The sacs of the RER are called cisternae and the space within each sac
is called the lumen. Within the RER are the protein products synthesized by
the ribosomes embedded in the RER membrane.
 The RER forms vesicles that contain their protein products, and sends these
vesicles to the Golgi for further processing.
 The RER is often found continuous with and extending from the surface of the
nuclear envelope of the nucleus. This facilitates the transport of mRNA from
the nucleus to the ribosomes of the RER to be used for protein synthesis.
 SER is called “smooth” because it lacks ribosomes. The cisternae of SER look
17. smooth
more tubular than sac-like. They function to synthesize and store lipids and
endoplasmic
steroids.
reticulum (SER)
 They are the organelles responsible for protein synthesis through a process
18. ribosomes
called translation. They decode the mRNA (which directs which amino acids
are assembled in which order) and assemble proteins according to the code on
the mRNA.
 Ribosomes can be found either freely floating in the cytoplasm or bound to
the rough endoplasmic reticulum surrounding the nuclear membrane. (The
“rough” in RER refers to the bumpy appearance of the RER due to its bound
ribosomes.)
 Ribosomes are not membrane bound organelles and disassemble into two
smaller protein subunits when not translating mRNA.
19. cytoplasm
20. *cell wall
21. cell / plasma
membrane
 This is the area that exists between the cell membrane and the nucleus. It
contains the cytosol (the liquid and dissolved contents of the cytoplasm) as
well as all the organelles (minus the nucleus). It is where the cellular
machinery (organelles) is stored and where the metabolism and specialized
functions of the cell are carried out.
 This is the outermost coating of the plant cell. It is rigid and tough and its
main role is that of structural support and physical protection. The rigidity of
the wall prevents the cell from over-expanding and helps the cell keep its
shape when water enters the cell.
 In plant cells, the cell wall is composed mostly of a polysaccharide called
cellulose.
 The semipermeable membrane that surrounds the cytoplasm of the cell. It
separates the interior contents of the cell from the external environment, and
its semipermeable nature allows for the selective traffic of substances into and
out of the cell.
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Created by Anh-Thi Tang – Tangstar Science
Copyright © 2015 Anh-Thi Tang (a.k.a. Tangstar Science)
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