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Biology
DNA, RNA, Proteins
& Genetic Engineering
DNA Learning Intentions
1.
2.
3.
4.
What is DNA?
What does DNA code for?
How does mRNA help make proteins?
Give examples of proteins
1. What is DNA?
Chromosomes are divided up into
packets of information called genes
Genes are made up from DNA & they
code for making proteins
DNA is made up 4 bases – A, T, G, C
How many chromosomes should humans have in each body
cell?
2. What is DNA?
DNA is a double stranded helix.
DNA is made up of complementary
DNA bases
The DNA bases are A, T, G, C
A pairs with T & G pairs with C
The order (sequence) of the
bases on DNA are very important!
What is DNA? (2:44)
3. DNA code
DNA carries the genetic code for
making really important proteins.
The DNA sequence of bases codes for
the order of AMINO ACIDS
Amino acids join together to make a
protein
The sequence of AMINO ACIDS
determines which type of PROTEIN
gets made
DNA Fact File (1:24)
4. What is mRNA?
DNA contains the genetic code to make proteins
mRNA copies the code from DNA in the nucleus
mRNA carries the code out of the nucleus, through
the cytoplasm to a ribosome
5. How do proteins get made?
DNA has the code for the protein
(e.g. salivary amylase)
1.
mRNA copies the DNA code
inside the nucleus
2.
mRNA carries the code from
the nucleus to a ribosome
3.
At a ribosome, amino acids
are placed in the order
relating to the code
4.
Amino acids join together to
make a protein
How proteins are made? (2:55)
Build a Play-doh model
6.Where do Proteins get made?
1.
2.
3.
4.
5.
In nucleus, mRNA
copies DNA code for
making protein
mRNA moves out
nucleus into cytoplasm
and carries code to
Ribosome
At a Ribosome, amino
acids line up according
to the code
The protein is made
(assembled) at the
Ribosome
The protein is
released from the cell
Nucleus (containing DNA
code)
mRNA (copies
the DNA code)
Ribosomes (the site
where proteins get
made (assembled)
7. Different types of proteins
The order of the amino acids determines the shape and function of
the protein produced.
The structure of a protein is important for its function as proteins
have a specific shape.
Proteins can be:-
structural (e.g. found in cell membrane)
enzymes (e.g. salivary amylase)
hormones (e.g. insulin)
antibodies (e.g. to fight infection)
Antibody image
8a) Proteins & Genetic Engineering
Genetic Engineering
Genetic Engineering is when genes from one organism are inserted
into another organism (e.g. genes from a human inserted into a
Insulin – video clip (2:29) Genetic Modification (2:49)
bacterium)
1.
The gene is identified (e.g. Human insulin)
2.
The gene is extracted from the chromosome
3.
The gene is inserted into a vector/bacterial plasmid
4.
The plasmid is put into a host cell (e.g. bacteria)
5.
Growth of transformed cells occurs, and desired gene product
is produced (insulin)
6.
Organisms which have had additional genes inserted into them
are called Genetically Modified (GM) Organisms
8b - Genetic Engineering
8c) Genetic Modifications
The GloFish
Zebrafish which have had genetic
information from bioluminescent
jellyfish added to its DNA.
The Grapple
A genetic cross between an apple and
a grape. The grapple was originally
designed to provide a much higher
vitamin-c dose per fruit for third
world aid. The majority of the
funding for the fruit came from
UNICEF
8d) Genetic Modifications
Poisonous Cabbage
The gene that codes for poison in scorpion tails has been
inserted into cabbage.
These genetically modified cabbages produce scorpion poison
that kills caterpillars when they bite leaves — but the toxin is
modified so it isn’t harmful to humans. Thus preventing crops
being destroyed by caterpillars.
Less Cow Methane
Cows release methane as a result of their digestion
process.
Methane is produced by a bacterium that feeds on the
grass and hay in the stomach of the cow.
Methane contributes to the greenhouse effect
Scientists have identified the bacterium responsible for
producing methane and have produced a strain of cattle
that produces 25% less methane than the average cow.
8e) Genetic Modifications
Silk in Milk
Strong, flexible spider silk is one of the most valuable materials
in nature. It can be used to make lots of products (eg. artificial
ligaments, parachute cords) The silk is hard to collect in large
quantities.
Researchers inserted a spiders’ dragline silk gene into the goats’
DNA in such a way that the goats would make the silk protein in
their milk. This “silk milk” could then be used to manufacture a
web-like material called Biosteel
Large Salmon
Genetically modified salmon grow twice as fast as the
conventional variety — the photo shows two same-age
salmon with the genetically altered one in the rear.
Genetically engineered Atlantic salmon has an added growth
hormone from a Chinook salmon that allows the fish to
produce growth hormone year-round.
8f) Genetic Modifications
Glow Cats
GLOW cats are used to help with AIDS research.
The cats glow green under UV light because the green fluorescent protein
(GFP) gene originating from jellyfish has been inserted in them.
The GM cats also carry a monkey gene, which protects monkeys from
infection by feline immunodeficiency virus or FIV – responsible for cat
AIDS.
Ear Mouse
The Vacanti mouse was a laboratory mouse that had what looked like
a human ear grown on its back.
The "ear" was actually an ear-shaped cartilage structure grown by
seeding cow cartilage cells into a biodegradable ear-shaped mold and
then implanted under the skin of the mouse