CONCEPTS EXPLORED IN THIS LESSON
1) The Discovery of the Cell
2) Cell Theory
3) Cellular Requirements
4) Prokaryotes vs. Eukaryotes
5) Structures in a General Plant Cell
6) Structures in a General Animal Cell
7) Three Important Cell Regions
8) Structures in Plant & Animal Cells
9) The Cell Membrane
10) The Nucleus
11) Mitochondria
12) Endoplasmic Reticula
13) Golgi, Vesicles and Vacuoles
14) Ribosomes
15) Cytoskeleton
16) Lysosomes
17) Peroxisomes
18) Membrane Junctions
19) Centrosomes & Centrioles
20) Flagella and cilia
21) Central Vacuole
22) Cell Wall
23) Chloroplasts
THE DISCOVERY OF THE CELL
Zacharias
Janssen
microscope
• He invented the __________.
• With it he could examine
(circa 1595)
magnification
specimens at a ____________
1000-2000 times their true size.
THE DISCOVERY OF THE CELL
Zacharias
Janssen
Robert
Hooke
• He studied cork
____ slices under a
microscope and saw tiny
structures he ended up calling
cells because the structures
"____",
resembled the chambers
________ of a
monastery.
THE DISCOVERY OF THE CELL
Zacharias
Janssen
Robert
Hooke
Anton van
Leeuwenhoek
lens technology.
• He improved on ____
• He was the first to examine and
microorganisms , like
describe ______________
bacteria, in a drop of water.
(Leeuwenhoek microscopes)
• He called them "little beasties".
THE DISCOVERY OF THE CELL
Zacharias
Janssen
Robert
Hooke
Anton van Matthias
Leeuwenhoek Schleiden
plants
• He established that ______
were composed of cells
____.
THE DISCOVERY OF THE CELL
Zacharias
Janssen
Robert
Hooke
Anton van Matthias Theodore
Leeuwenhoek Schleiden Schwann
animals
• He established that _______
were composed of cells
____.
THE DISCOVERY OF THE CELL
Zacharias
Janssen
Robert
Hooke
Anton van Matthias Theodore
Leeuwenhoek Schleiden Schwann
Rudolph
Virchow
• He established that every cell
other cells
came from _________.
THE DISCOVERY OF THE CELL
Zacharias
Janssen
Robert
Hooke
• The last three
scientists put
together the
principles of
CELL
THEORY
___________.
Anton van Matthias Theodore
Leeuwenhoek Schleiden Schwann
Rudolph
Virchow
CELL THEORY
Zacharias
Janssen
Robert
Hooke
• The last three
scientists put
together the
principles of
CELL
THEORY
___________.
Anton van Matthias Theodore
Leeuwenhoek Schleiden Schwann
Rudolph
Virchow
1) All living things are made up of one or
cells
more ____.
units of living things.
2) Cells form the basic
_________
pre-existing cells.
3) All cells come from __________
CELLULAR REQUIREMENTS
What functions do all cells need to perform?
1) Control: Cells need a way to control and direct
their own processes and functions.
2) Nutrients: Cells need a way to obtain and digest nutrients.
3) Waste: Cells need a way to get rid of waste.
4) Energy: Cells need a way to obtain and use energy.
5) Transport: Cells need a way to
transport substances.
6) Cell Division: Cells need to make more of themselves.
PROKARYOTES vs. EUKARYOTES
two main different types of cells:
• There are ____
1) Prokaryotic Cells
• Any organisms made up of
prokaryotic cells are called
prokaryotes
___________.
2) Eukaryotic Cells
• Any organisms made up of
eukaryotic cells are called
eukaryotes
__________.
• These two types of cells differ in many ways. The following
are some of the most important ones.
PROKARYOTES vs. EUKARYOTES
SIZE
10-100 µm
Does not have a
true nucleus, only
a nucleoid region.
NUCLEUS
Has a true
membrane
bound nucleus.
Has no membrane
bound organelles.
MEMBRANE
BOUND
ORGANELLES
Has membrane
bound organelles.
< than 10µm
Only one circular
piece of DNA with
no proteins.
DNA
Small ribosomes.
RIBOSOMES
All prokaryotes are
unicellular organisms.
Asexual only – through
binary fission.
Eubacteria and
archaebacteria.
NUMBER OF CELLS
REPRODUCTION
KINGDOMS OF LIFE
Many linear
pieces of DNA
with proteins.
Large ribosomes.
Eukaryotes are either
unicellular or multicellular.
Sexual and asexual –
through mitosis & meiosis.
Protists, fungi, plants
and animals.
STRUCTURES IN A GENERAL ANIMAL CELL
G nucleus
Name as many structures as you can.
smooth
endoplasmic L
reticulum
flagellum M
rough
endoplasmic N
reticulum
ribosome O
cytoskeleton P
mitochondrion Q
centriole R
cilium S
peroxisome T
cytoplasm/cytosol U
nuclear
A membrane
B nucleoplasm
C chromosome
D nucleolus
E chromatin
F nuclear pore
H Golgi body
I vesicle
J cell membrane
K lysosome
Which structures are not found in plant cells?
STRUCTURES IN A GENERAL PLANT CELL
G nucleus
Name as many structures as you can.
ribosome N
smooth
endoplasmic O
reticulum
central vacuole P
cytoskeleton Q
chloroplast R
mitochondrion S
cytoplasm/ T
cytosol
plasmodesma U
rough endoplasmic
reticulum
M
A nuclear pore
B nuclear
membrane
C chromosome
D chromatin
E nucleolus
F nucleoplasm
H Golgi body
I vesicle
J cell wall
K cell membrane
L peroxisome
Which are not found in animal cells?
THREE IMPORTANT CELL REGIONS
1) Cell Membrane
2) Nucleus
• This is the outermost
• The control
______ center of the cell that
boundary
________ of the cell.
contains the DNA
____ (deoxyribonucleic acid) which directs
the functioning of the cell.
3) Cytoplasm
• The part between the cell
•
•
membrane and the nucleus.
It contains a liquid called
______.
cytosol
Within the cytosol are
organelles which are special
_________
structures that carry out
different cell functions
________.
THREE IMPORTANT CELL REGIONS
• As well, two other important terms are:
inside of the cell.
1) Intracellular
__________ which refers to the area _____
2) Extracellular
__________ which refers to the area outside
______ of the cell.
STRUCTURES IN PLANT AND ANIMAL CELLS
Animal Cell
Plant Cell
STRUCTURES IN PLANT AND ANIMAL CELLS
Animal Cell
Plant Cell
STRUCTURES IN PLANT AND ANIMAL CELLS
Animal Cell
Plant Cell
nucleus
lysosomes
nucleolus
chromatin/DNA
tight junctions
cell membrane
gap junctions
peroxisomes
extracellular
endoplasmic reticulum
matrix
(smooth & rough)
desmosomes
mitochondria
centrioles
ribosomes
cytoskeleton
flagella
Golgi body
cilia
vesicles
(in very few plants)
cell wall
central vacuole
plasmodesmata
chloroplasts
THE CELL MEMBRANE
• The cell membrane is also known as the
plasma membrane
________________.
• It is composed of two layers
phospholipids
of ____________.
aqueous environment
• It is called the
phospholipid
bilayer
_________________
because it is made of
aqueous environment
• A phospholipid is a these two layers.
phosphate
fat composed of:
type of ___
head
1) A __________
hydrophilic “water loving”
fatty
phosphate head that faces the
acid tails
aqueous environment.
2) Two ___________
hydrophobic “water-fearing” fatty
acid tails which face other fatty acid tails to
avoid being near the water.
THE CELL MEMBRANE
• Besides the phospholipid bilayer, the cell membrane also
sterols and ______
sugars within the bilayer
contains: proteins
_______ , ______
which help it perform specific functions.
Fluid Mosaic Model
• This model of the membrane is called the _________________.
THE CELL MEMBRANE
The cell membrane has several important functions:
1) It forms a physical ______
barrier to protect the inside of the cell
from the outside environment.
2) It controls the transport
________ of
substances into and out of the cell.
This is possible because the
membrane is semi-permeable
______________
meaning only certain substances
are allowed to cross it.
3) It plays a role in cell-to-cell communication
_____________.
4)
Knock,
Knock!
Who's
there?
THE CELL MEMBRANE
The cell membrane has several important functions:
1) It forms a physical ______
barrier to protect the inside of the cell
from the outside environment.
2) It controls the transport
________ of
substances into and out of the cell.
This is possible because the
membrane is semi-permeable
______________
meaning only certain substances
are allowed to cross it.
3) It plays a role in cell-to-cell communication
_____________.
4)
Cows
go.
Cows
go who?
THE CELL MEMBRANE
The cell membrane has several important functions:
1) It forms a physical ______
barrier to protect the inside of the cell
from the outside environment.
2) It controls the transport
________ of
substances into and out of the cell.
This is possible because the
membrane is semi-permeable
______________,
meaning only certain substances
are able to cross it.
3) It plays a role in cell-to-cell communication
_____________.
4) It is an attachment
__________ surface for cell
walls, other cells and the intracellular
cytoskeleton.
NO!
Cows go moo!
*groan*
THE NUCLEUS
THE NUCLEUS
• The nucleus is composed of:
1)
2)
3)
4)
Nuclear Membrane
Nucleoplasm
Nucleolus
Chromatin or Chromosomes
THE NUCLEUS
• The nucleus is composed of:
1) Nuclear Membrane
• This is a double
______ membrane
and it contains nuclear
___________
pores .
TEM micrograph of nuclear pores.
two lipid
bilayers
nuclear
pores
• It surrounds and protects
_______ the
contents of the nucleus.
• It controls the transport
________ of
nucleus
substances between the _______
cytoplasm , especially
and the _________
through the nuclear pores.
THE NUCLEUS
• The nucleus is composed of:
2) Nucleoplasm
liquid within the nucleus.
• The _____
• It is similar to the cytosol
______ within the cytoplasm.
THE NUCLEUS
• The nucleus is composed of:
3) Nucleolus
TEM micrograph of nucleus and nucleolus.
• Made up of a combination of
RNA and proteins
____
_______.
synthesis
• Site of ribosome
________________.
THE NUCLEUS
• The nucleus is composed of:
DNA wrapped around
• Strands of ____
proteins called histones
_______ create
4) Chromatin & Chromosomes _________
chromatin .
• Chromatin forms chromosomes
____________
chromosome
chromatin
histones
DNA
when it condenses
_________ into easily
visible strands during cell division.
THE NUCLEUS
center for
• The main function of the nucleus is to be the control
____________
the cell.
proteins
• The _____
DNA contains all the instructions needed to make _______
cell division and direct all the ________
activities of
for the cell, to control __________
the cell.
Animal Cell Division
MITOCHONDRIA
mitochondrion
• The singular for mitochondria is _____________.
• A mitochondrion is composed of:
outer membrane (smooth)
double
inner membrane
membrane
(folded)
intermembrane space
(liquid between membranes)
matrix
(liquid within
christae
inner membrane) (folds of the inner
membrane)
TEM micrograph of a mitochondrion.
• Each one also has a singular circular chromosome
___________ as well as its
ribosomes which allow it to self-replicate
own _________
___________.
MITOCHONDRIA
energy for the
• The main function of mitochondria is to produce ______
cellular respiration
cell in a chemical process called ________________.
oxygen as reactants.
• It uses glucose
______ and ______
dioxide and water
• It produces carbon
____________
_____ as products, as well as
energy in the form of a molecule called ATP
___ (adenosine
______
triphosphate).
carbon dioxide
glucose
water
oxygen
energy (ATP)
Chemical formula for cellular respiration:
+
+
+
ENDOPLASMIC RETICULUM
• The endoplasmic reticulum is formed from a
membranes which form sac
___-like
network of __________
tube -like structures.
and ____
Rough
Endoplasmic Reticulum
• Rough E.R. is called "rough"
because it is embedded with
ribosomes
_________.
• It is found extending from
nuclear membrane
the ________________
surrounding the nucleus.
ENDOPLASMIC RETICULUM
• The endoplasmic reticulum is formed from a
membranes which form sac
___-like
network of __________
tube -like structures.
and ____
Rough
Endoplasmic Reticulum
• Rough E.R. is called "rough"
because it is embedded with
ribosomes
_________.
Smooth Endoplasmic Reticulum • It is found extending from
nuclear membrane
the ________________
• Smooth E.R. is called "smooth"
surrounding the nucleus.
because does not contain
ribosomes
_________.
TEM micrograph of S.E.R. and R.E.R.
ENDOPLASMIC RETICULUM
• The endoplasmic reticulum is formed from a
membranes which form sac
___-like
network of __________
tube -like structures.
and ____
Rough
Endoplasmic Reticulum
• Rough E.R. is called "rough"
because it is embedded with
ribosomes
_________.
Smooth Endoplasmic Reticulum • It is found extending from
nuclear membrane
the ________________
• Smooth E.R. is called "smooth"
surrounding the nucleus.
because does not contain
• Functions to synthesize
ribosomes
_________.
proteins
_______.
fats
• Functions to synthesize ____.
GOLGI BODY, VESICLES and VACUOLES
Golgi Body
• Also called the
Golgi
apparatus
_____________.
• It resembles a stack
pancakes
of membrane "________".
Golgi body
TEM micrograph of Golgi body.
GOLGI BODY, VESICLES and VACUOLES
Golgi Body
• Also called the
Golgi
apparatus
_____________.
R.E.R.
• It resembles a stack
pancakes
of membrane "________".
receiving
• It is responsible for ________
vesicle
Golgi body
lysosome
vesicle
vacuole
vesicles containing _______
proteins from
processing these
the R.E.R.
_____ , _________
packaging
proteins, and then _________
them either within:
1) Vesicles for transport
________.
2) Vacuoles for storage
______ .
3) Lysosomes for…Find out later.
RIBOSOMES
protein
• Each ribosome is composed of two _______
subunits mixed with _____.
rRNA
large subunit
• In prokaryotes, they are found
____
free in the cytoplasm.
• They have what are
called 70S
___ ribosomes.
free
• In eukaryotes, they are found ____
in the cytoplasm as well as bound
rough endoplasmic reticulum
to _________________________.
• They have what are called 80S
___
ribosomes which are larger
_____ than
those of prokaryotes.
small subunit
RIBOSOMES
large subunit
free ribosomes
small subunit
ribosomes on R.E.R.
TEM micrograph of bound
and unbound ribosomes.
free
• In eukaryotes, they are found ____
in the cytoplasm as well as bound
rough endoplasmic reticulum
to _________________________.
• They have what are called 80S
___
ribosomes which are larger
_____ than
those of prokaryotes.
RIBOSOMES
amino acids together in order to
• They function to assemble ___________
proteins
make ________.
amino acids
protein
ribosome
CYTOSKELETON
scaffolding found within all cells and made
• It is the network of __________
proteins . (The cytoskeleton in prokaryotes
from different types of _______
is newly discovered and not well understood. We will focus on the
eukaryotic cytoskeleton.)
membrane
• It is attached to the cell
_____________
mitochondrion
Rough E.R.
organelles within the
as well as to _________
cytoplasm.
cell
membrane
intermediate
filaments
microfilaments
microtubules
CYTOSKELETON
• It is composed of _____
three types of _______
protein fibers grouped
according to size
___.
1) Microfilaments
• Thinnest: 7nm
2) Intermediate
Filaments
• Medium size: 10nm
mitochondrion
Rough E.R.
cell
membrane
3) Microtubules
• Thickest: 25nm
intermediate
filaments
microfilaments
microtubules
CYTOSKELETON
• The cytoskeleton is responsible for the movements
__________ of the cell like:
1) Movement of Organelles
2) Cytoplasmic Streaming
mitochondrion
Rough E.R.
3) Movement of Cilia and Flagella
4) Movement of Chromosomes
during Mitosis and Meiosis
cell
membrane
intermediate
filaments
microfilaments
microtubules
CYTOSKELETON
• The cytoskeleton is responsible for the movements
__________ of the cell like:
1) Movement of Organelles
• The cytoskeleton is
responsible for moving
vesicles, vacuoles,
ribosomes and other
organelles around the cell.
mitochondrion
Rough E.R.
cell
membrane
intermediate
filaments
microfilaments
microtubules
CYTOSKELETON
• The cytoskeleton is responsible for the movements
__________ of the cell like:
2) Cytoplasmic Streaming
cytoplasm
• The bulk movement of the _________.
• In amoeba, the streaming
mitochondrion
Rough E.R.
produces pseudopods
__________ – “fake
feet” – which help it move
and capture food.
cell
membrane
Cytoplasmic Streaming in Amoeba
intermediate
filaments
microfilaments
microtubules
CYTOSKELETON
• The cytoskeleton is responsible for the movements
__________ of the cell like:
3) Movement in Cilia and Flagella
4) Movement of Chromosomes
during Mitosis and Meiosis
mitochondrion
Rough E.R.
cell
membrane
Animal Cell Mitosis
intermediate
filaments
microfilaments
microtubules
LYSOSOMES
body
• Lysosomes are formed from the Golgi
_________.
enzymes that can break
• These membrane sacs contain hydrolytic
________________
down (digest) various substances.
lysosome
Golgi
body
LYSOSOMES
• They have several important functions:
1) Digestion • Food particles are
engulfed by the cell
vacuole
into a food
___________.
• Lysosome fuses with vacuole and
the enzymes
_______ digest the food.
mitochondrion
peroxisome
TEM micrograph of lysosome digesting
a mitochondrion and a peroxisome.
organelles are
2) Autophagy • Damaged _________
digested by lysosomes.
3) Autolysis
enzymes mix
with food
• Cell self-destruction
_____________
through the rupture of all phagocytosis
of food
lysosomes.
blood cells
• Used by white
______________
food
to kill many engulfed
vacuole
bacteria at once. food
enzymes
digest
organelle
organelle
lysosome
Golgi
body
PEROXISOMES
• Peroxisomes resemble _________
lysosomes because they are membrane
bound organelles containing enzymes
_______ . However, there are very
important differences.
• Peroxisomes come from the ___________
endoplasmic
________ while lysosomes come from
reticulum
body
the Golgi
_________.
TEM micrograph of peroxisome.
peroxisome
lysosome
PEROXISOMES
• Peroxisomes have several important functions:
1) They contain enzymes called oxidases
_______ which are vital to the
fatty acids and amino
acids
metabolism of _________
__________.
2) They produce ________________
hydrogen peroxide which is
a toxic by-product of their metabolic
activities. To get rid of this, they
catalase
use an enzyme called _______
to break down the hydrogen
peroxide into harmless _____
water
and oxygen
______.
3)
catalase
+
peroxisome
lysosome
PEROXISOMES
• Peroxisomes have several important functions:
1) They contain enzymes called oxidases
_______ which are vital to the
fatty acids and amino
acids
metabolism of _________
__________.
2) They produce ________________
hydrogen peroxide which is
a toxic by-product of their metabolic
activities. To get rid of this, they
catalase
use an enzyme called _______
to break down the hydrogen
peroxide into harmless _____
water
and oxygen
______.
3) In plant seeds, they convert
_________
____________
fatty acids to carbohydrates
to aid germination.
peroxisome
lysosome
MEMBRANE JUNCTIONS
multicellular organisms, cells are connected to one another
• In ___________
by various membrane junctions.
1) Tight Junctions
2) Desmosomes
animal cells
3) Gap Junctions
4) Plasmodesmata
plant cells
MEMBRANE JUNCTIONS
1) Tight Junction
• Made from a network of
protein sealing strands
______ .
prevents passage of
• It ________
substances between cells.
holds
• ItTEM
_____
two cells together.
micrograph of
2) Desmosome
tight junctions.
adhesion proteins
• Made of ________
attached to intermediate
___________
filaments
________ on each side.
• It attaches
_______ two cells together.
3) Gap Junction
TEM micrograph of
a desmosome.
• Made up of proteins called
connexins which form
_________
cylindrical channels
________.
allows
• ItTEM
_____
the passage of ions and
micrograph of
gap junctions
.
small
molecules
between cells.
MEMBRANE JUNCTIONS
TEM micrograph of
plasmodesmata.
4) Plasmodesmata
channels that cross cell walls between plant cells.
• These are ________
reticulum .
• They originate from the endoplasmic
___________________
transport and communication
• They enable ________
_____________ between cells.
Plasmodesma is the singular form.
• ____________
CENTROSOMES and CENTRIOLES
Centrosome
• Centrosomes are considered MTOCs, or microtubule
__________ organizing
synthesized .
centers. This is where microtubules are __________
Centrioles
• Within the centrosome, there are a pair
___ of cylindrical-shaped
centrioles that are made from triplets
______ of microtubules. They are
oriented ____________
perpendicular to one another.
centriole pair
centriole
centriole 2
microtubule
TEM micrograph of centriole pair.
triplet
centriole 1
CENTROSOMES and CENTRIOLES
Centrosome
• Centrosomes are considered MTOCs, or microtubule
__________ organizing
synthesized .
centers. This is where microtubules are __________
Centrioles
• Within the centrosome, there are a pair
___ of cylindrical-shaped
centrioles that are made from triplets
______ of microtubules. They are
oriented ____________
perpendicular to one another.
• Each non-dividing cell has one
___
pair of centrioles. However, for
cell division, the centrosome
replicates
________ the pair, and the two
pairs are responsible for the
spindle
formation of the mitotic
____________
which is used to move
chromosomes during cell division.
____________
FLAGELLA and CILIA
• In animals and protists, both flagella and cilia
are composed of microtubules
___________. Prokaryotes have no cilia and
flagellin
their flagella are composed of a protein called _______.
cell membrane and the main
• Both extend from the surface of the _____________
difference between the two depend on size
___ and quantity
_______.
Cilia
numerous
• They are smaller
______ and _________.
• The singular form is cilium
_____.
Flagella
fewer
• They are longer
_____ and _____.
• The singular form is
flagellum
________.
FLAGELLA and CILIA
• In unicellular
_________ organisms, both flagella and cilia
function to produce locomotion
__________ or to move food
____ towards the
organism.
Climacostomum Ciliate Protozoan
Swimming Human Sperm
FLAGELLA and CILIA
• In unicellular
_________ organisms, both flagella and cilia
function to produce locomotion
__________ or to move food
____ towards the
organism.
multicellular organisms, certain cells contain cilia to help
• In ___________
surfaces .
move substances across tissue
____________
Cilia Move Debris out of Trachea
Cilia Move Egg through Fallopian Tube
CENTRAL VACUOLE
largest organelle within a plant cell, and often takes up
• It is the ______
the majority
_______ of the cytoplasm of a plant cell.
vesicles
• It is formed from the fusion of many _______.
liquid surrounded by a
• It is composed of a _____
membrane called the tonoplast
________.
chloroplast
nucleus
TEM micrograph of central vacuole.
CENTRAL VACUOLE
• It has two main important functions:
hydrostatic pressure pushing
1) Turgor Pressure: This is the __________
outwards on the cell due to the volume of
_____
water within the vacuole.
This helps keep the cell
turgid
_____ (firm).
2) Storage: The vacuole
functions to
water ,
store _____
waste , and
_____
ions
____.
CELL WALL
• The cell wall in plants is
located outside of the
cell membrane , and is
_____________
composed of a
polysaccharide called
cellulose
________.
SEM micrograph of cellulose.
CELL WALL
• The cell wall in plants is
located outside of the
cell membrane , and is
_____________
composed of a
polysaccharide called
cellulose
________.
• The cell wall has two main
important functions:
Cell wall fights back!
1) Support and Protection:
Cellulose is tough and rigid.
2) Prevents Overexpansion:
hydrostatic pressure
The wall prevents _________________
from over-expanding the cell.
CHLOROPLAST
• A chloroplast is composed of:
chloroplasts
lamella outer membrane
double
(links two
inner membrane
grana;
membrane
lamellae is
thylakoid
plural)
(one photosynthetic
membrane sac)
thylakoid
membrane
(photosynthetic)
stroma
(liquid
granum
thylakoid lumen
(a stack of inside inner
(space inside
membrane)
thylakoids;
TEM micrograph of granum.
thylakoid)
grana is
• Like mitochondria, they also have their own circular
plural)
chromosome
ribosomes for _____________.
self-replication
___________ and _________
CHLOROPLAST
• The main function of the chloroplast is to produce glucose
______ for
photosynthesis
the plant cell in a chemical process called _____________.
dioxide and water
• It uses carbon
____________
_____ as reactants, and a green
chlorophyll to capture the sunlight
pigment called __________
_______ needed to
power the reaction.
• It produces glucose
______ and oxygen
______ as products.
glucose
carbon dioxide
water
oxygen
sunlight
Chemical formula for photosynthesis:
+
+
chlorophyll
+
Created by Anh-Thi Tang – Tangstar Science
Copyright © August 2014 Anh-Thi Tang (a.k.a. Tangstar Science)
All rights reserved by author.
This document is for personal classroom use only.
This entire document, or any parts within, may not be electronically
distributed or posted to any website including teacher or classroom blogs or
websites.
http://www.teacherspayteachers.com/Store/Tangstar-Science