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In-Gene-ious
Delving into Cells, Chromosomes,
Genes, Proteins and DNA!
by Jacinta Duncan
The Gene Technology Access Centre
Modified by Stephen Gloury and Eryn O’Mahony
1
Discovering Small Differences
Pull your
hair back.
Widows
peak or
none?
Which inherited trait do you have?
Click and Fill in your worksheet as
you determine each one.
Cross your
arms….are you
left over right or
right over left?
Earlobes
Attached or
unattached?
Second toe
longer or
shorter than
your big toe?
Mid-digit hair on
fingers?
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WE ARE DIFFERENT IN MANY WAYS,
BUT IN MANY WAYS WE ARE THE SAME!
I wonder how, I wonder
why
I’m 61% like a fly?
Now here’s a shock
that’s sort of grouse
We’re 99% like a mouse!
It makes you stop, it
makes you think
How similar are we to a
chimp?
Source:
Mouse http://animals.timduru.org/dirlist/mouse/mouse.jpg
Drosophila: http://www.innate.se/drosophila.jpg
Chimpanzee: http://www.utalii.com/Hotels/images/Chimpanzee.jpg
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You have trillions of
cells in your body!
1
Red blood cells to carry
oxygen around the body
And
White blood cells to fight
infections
2
Nerve cells send
electrical signals so your
brain can communicate
with the rest of the
cells in your body
3
Fat Cells to store
excess energy
4
Muscle cells for
movement
Here are some
examples of cells
in your body.
Can you guess
what they are
and what they
do?
Click on them to
check your
answer.
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Source:
Blood cells: http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/35a5c/35A5C297.jpg
Nerve cell: http://www.technovelgy.com/graphics/content/nervecell.jpg
Fat cells: http://casweb.cas.ou.edu/pbell/Histology/Images/Slides/Connective/pl.skin.adipose.jpg
Muscle cells: http://www.meddean.luc.edu/lumen/MedEd/Histo/HistoImages/hl3A-42.jpg
Bone cell: http://www.meddean.luc.edu/lumen/MedEd/Histo/HistoImages/hl4A-40.jpg
Bone cells produce
calcium carbonate
to support the body
4
You find DNA inside nearly every
cell in your body.
Each cell contains the same
DNA.
The DNA is found inside the
nucleus of the cell.
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DNA is in the cell nucleus
All mature cells contain DNA except your red blood cells.
DNA is found in the nucleus. This is a large structure found in the cell.
Can you locate it in the cell below? Click to check your answer.
Nucleus
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Source: http://www.tokyo-med.ac.jp/genet/picts/cell-e.jpg
DNA is packed into chromosomes
You have 46 chromosomes
in each of your body cells.
You inherited these from
your parents: 23 from
mum and 23 from dad
Click on the button to see
what your chromosomes
look like.
The chromosomes you
inherit determine what you
look like.
Human chromosomes
Source:
Chromosome: http://data.over-blog.com/lib/0/4/3540/pics/Articles/chromosome.jpg
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Fertilisation Event
An egg has 23 chromosomes and a sperm has 23 chromosomes.
The cell that results from fertilisation contains 46 chromosomes or 23 pairs.
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Embryo Development
All of your body cells come
from this one fertilised
cell. Every time cells
divide they copy their DNA
and pass it on to their
daughter cells.
Embryo
Development
This means that all of your
body cells have the same
copy of DNA or the same
chromosomes as the
original cell.
Cells end up doing
different jobs because of
the genes that are turned
Pictures from Nova Online
on or off.
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Genes
Sections of the
chromosome shown here
have been coloured in.
Each section is a piece of
DNA called a gene.
Look at some genes
on your chromosomes.
Click on Tour and then
“Genome spots”
Source: Chromosome: http://academy.d20.co.edu/kadets/lundberg/dnapic2.html
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Chromosome Number
One is the largest
chromosome. It has 2,968
genes.
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A gene acts as a recipe or
code for making a protein.
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WHAT ARE PROTEINS?
WHY ARE THEY SO IMPORTANT?
70% of your body is water. 15% is protein!
Many parts of your body are built out of proteins!
Many parts of your body are built by proteins!
You drink to get water and you eat food
containing protein to get the building
blocks for making proteins.
The building blocks are amino acids.
You’ve all used lego pieces or blocks to
build things. In a similar way, your body
builds proteins out of amino acids
Source: http://thehumanbodyfilm.com/home.html
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1. Amylase – a protein
in your saliva that
breaks down starch
(found in biscuits,
cereal, bread, etc.) into
smaller sugars
2. Two proteins for
muscle movement –
actin and distrophin
3. Another protein
found in muscle is
myoglobin. It stores
the oxygen needed
for cells to do their
work
4. Keratin – a
protein that
makes your nails
and hair tough
Proteins in You!
5. Your heart
pumps blood. The
blood contains red
blood cells. These
red blood cells
contain the protein
haemoglobin.
Haemoglobin
carries oxygen to
cells all around the
body.
6. All of your joints
contain tendons to
join bones and
cartilage to stop
bones rubbing
together and to
absorb shock. The
protein here is
collagen – a tough
and flexible protein.
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So…we’re all so similar
because of our genes
and the proteins we
make!
15
In fact it is believed the
human genome is almost
exactly the same in all
people. 99.9%
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What makes us unique is the
non coding DNA. This is
quite different in each
individual.
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But what is a gene made out
of ?
The molecule of life….
DNA
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What does DNA stand for?
De
oxy
ribo
Nucleic
Acid
Missing or
less
Oxygen
Sugar
Nucleus
Acid
(think Ribena!)
(part of your
cells)
(think lemons
and oranges!)
1. PRACTICE SAYING ‘DEOXYRIBONUCLEIC ACID’ BY
BREAKING IT DOWN INTO SMALLER PARTS.
THESE PARTS GIVE YOU CLUES ABOUT THE MOLECULE.
2. TRY TO GUESS WHAT EACH PART MIGHT MEAN AND THEN
CLICK TO CHECK YOUR ANSWER (Do this in order)
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Would you eat DNA?
All living things are made up of cells.
Do you think that plant cells contain DNA?
Let’s investigate…..
DNA extraction protocol
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DNA
DNA is made up of two strands (shown here in blue and
red). The strands are held together by nitrogen bases
(shown here in yellow)
There are four nitrogen
bases:
Cytosine, Guanine,
Adenine and Thymine
What pairs with C?
What pairs with A?
http://academy.d20.co.edu/kadets/lundberg/dnapic2.html
http://www.tokyo-med.ac.jp/genet/picts/dna.jpg 21
The code
In each gene (length of DNA) there is a code for
making protein. The code is determined by the
order of the nitrogen bases A, T, G and C.
The code is copied and then read by your cell
machinery so proteins can be made.
An animation of this is on the DNAi DVD
distributed free to schools by GTAC
Order Form
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A gene for keratin, the protein your hair is made out of, is located on
chromosome 12.
How many nitrogen bases make up the coding part of this gene (shown below)?
1 ccctgcactt gggagccggt agcactccta tcactgcttc tcaacccgtg agctaccagc tgtgtcatga gctgcagaca gttctcctcg
tcctacttga gccgcagcgg cgggggtggc gggggcggcc tgggcagcgg gggcagcata aggtcttcct acagccgctt
cagctcctc gggggcggtg gaggaggggg ccgattcagc tcttctagtg gctatggtgg gggaagctct cgtgtctgtg
ggaggggagg cggtggcagt tttggctaca gctacggcgg aggatctggg ggtggtttta gtgccagtag tttaggcggt ggctttgggg
gtggttccag aggttttggt ggtgcttctg gaggaggcta tagtagttct gggggttttg gaggtggctt tggtggtggt tctggaggtg
gctttggtgg tggctatggg agtgggtttg gggggtttgg gggctttgga ggtggtgctg gaggaggtga tggtggtatt ctgactgcta
atgagaagag caccatgcag gaactcaatt ctcggctggc ctcttacttg gataaggtgc aggctctaga ggaggccaac aacgacctgg
agaataagat ccaggattgg tacgacaaga agggacctgc tgctatccag aagaactact ccccttatta taacactatt gatgatctca
aggaccagat tgtggacctg acagtgggca acaacaaaac tctcctggac attgacaaca ctcgcatgac actggatgac ttcaggataa
agtttgagat ggagcaaaac ctgcggcaag gagtggatgc tgacatcaat ggcctgcggc aggtgctgga caatctgacc atggagaagt
ctgacctgga gatgcagtat gagactctgc aggaggagct gatggccctc aagaagaatc ataaggagga gatgagtcag
ctgactgggc agaacagtgg agatgtcaat gtggagataa acgttgctcc tggcaaagat ctcaccaaga ccctcaatga catgcgtcag
gagtatgagc agctcattgc taagaacaga aaggacatcg agaatcaata tgagactcag ataacccaga tcgagcatga ggtatccagt
agtggtcagg aggtgcagtc cagtgccaag gaggtgaccc agctccggca cggtgtccag gagttggaga ttgagctgca gtctcagctc
agcaagaaag cagctctgga gaagagcttg gaagacacga agaaccgcta ctgtggccag ctgcagatga tccaggagca
gatcagtaac ttggaggccc agatcactga cgtccggcaa gagatcgagt gccagaatca ggaatacagc cttctgctca gcattaagat
gcggctggag aaggaaatcg agacctacca caacctcctt gagggaggcc aggaagactt tgaatcctcc ggagctggaa
aaattggcct tggaggtcga ggaggaagtg gaggcagtta tggaagagga tccaggggag gaagtggagg cagctatggt
ggaggaggaa gtggaggtgg ctatggtgga ggaagtgggt ccaggggagg aagtggaggc agctacggtg gaggaagtgg
ttctggagga ggtagtggag gtggctatgg tggaggaagt ggaggtggcc atagcggagg aagtggaggt ggtcatagtg
gaggaagtgg gggcaactat ggaggaggaa gtggctctgg aggaggaagt gggggtggct atggtggagg aagtgggtcc
aggggaggaa gtggaggcag ccatggtgga ggaagtggtt ttggaggtga aagtggaggc agctacggag gcggtgaaga
agcgagtgga agtggtggcg gctacggagg aggaagcgga aaatcatccc attcctagtc ttcttcctca aaatctggtg accaagatga
gacaaaaggc ttcctttcgc gatactagag cctctgtaaa cttctcctgc ccagccccag ctgagcatcc ccagatgggc agactcccga
tgaagcctgc ttattggatc ctgacatcag gaatagctgg caacaagccc ctgtgcccgt ttgggactga actgacttgg catatgtgcc
tctggctttc cattggcttc caaccctgct tggctttgat gccttcaggg ttggggagac agacctcttt cctctctctg gcctggggtg
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ctctcacacc ctgcacgatc ttgactataa taaagcttcc ctactgc 2287
Dystrophin is the largest known
human gene. It has 2.4 million
bases and it takes the ce11 16
hours to copy.
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Protein Primary Structure
The primary structure is the sequence of amino
acids that are linked together to make a
polypeptide
http://www.mywiseowl.com/articles/Image:Protein-primary-structure.png
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Protein Secondary Structure
The secondary structure of proteins shows how they fold
up into
Alpha helices
Beta sheets
Random coils
Source: http://www.rothamsted.bbsrc.ac.uk/notebook/courses/guide/prot.htm#I
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Proteins fold again…
to gain the shape that is required for them to work properly.
This is important. If it goes wrong, the protein often can’t do its
job!
Source: http://fig.cox.miami.edu/~cmallery/150/chemistry/hemoglobin.jpg
Proteins can consist of one or more polypeptides. Haemoglobin
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has 4!
So, why are we so similar to a
mouse?
You will use the protein amylase to investigate this.
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Looking at Amylase
Amylase is a protein that cuts small maltose sugar molecules off
starch molecules. This is important as we need the sugar for
energy
Click on the starch molecule to see amylase in action
STARCH
AMYLASE
MALTOSE
STARCH
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Comparing the amylase code
Many living things on earth have the protein
amylase. They need it to cut sugars off starch so
they can use the sugar for energy.
We can start to get a picture of how closely related
living things are by comparing the code in their
genes (the genetic code = their genome).
You will act as code investigators. Click on the button
below to compare the codes for the protein amylase in
different living organisms
Code investigators
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The relationship tree
The relationship tree below has been made by comparing the code found in the
amylase gene for the rat, fruit fly, mouse, chicken and human.
The more similar the organism, the less distance between them. When you see a
fork in a line (split) this means that the animals have become different to each
other.
Use the tree to answer the
following questions:
Which two are more closely
related?
•The Fruit fly and the chicken OR
•The rat and the mouse?
Do you think you are more closely
related to a chicken or a mouse?
Explain
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Taking it a step further…
1. Three new organisms have been
added to the tree and one
removed. What are they?
2. Bacteria and fungi don’t eat
food like the other organisms.
They are decomposers. They
digest starch using amylase
protein and then absorb the
sugar products. How might they
get the amylase to the starch?
3. Draw in a line to show where
you think a chimpanzee would
be on this tree.
4. Click to see another version of
this tree
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Explore your proteins
Scientists have worked out the shape of many proteins by
conducting experiments. When they have their results,
they publish them and this information is then entered
into supercomputing systems for people to access.
You can view the three dimensional structure of some of
your proteins using the computer program Cn3D.
Download Cn3D
Haemoglobin
Amylase
Collagen
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Research another protein. Discuss what you can learn about
its structure, function and the organism it comes from using
the skills you learned today and website resources.
You can explore a number of proteins using Cn3D. Go to the following
URL:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Structure
In the “for” box, try some of the proteins listed below (one at a time)
and then hit “go”. You will get a list of options. Click on the writing in
blue to select one. A new page will appear. Click on View 3D structure
button. Explore using your Cn3D skills.
Misc
Enzymes
Genetics
Toxins
Collagen
Amylase
Endonuclease
Ricin
Tubulin
Rubisco
Taq DNA Polymerase
Arsenic
Porphyrin
Pepsin
Ribosome
Tetanus toxin
Prion
Alcohol dehydrogenase
Helicase
Funnel web toxin
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