Transcript Gene Expression

Binary Code
Does it mean anything?
0100100100100000011011000110111101110110011001
1001000000110001001101001011011110110110001101
11011001110111100100101110001000000010000001001
01011100100010111000100000010010000110000101101
00011011000110100101101000011000010110111000100
00011010010111001100100000011011010111100100100
00011001100110000101110110011011110111001001101
01011101000110010100100000011101000110010101100
010110001101101000011001010111001000101110
Morse Code
Does it mean anything?
.. / .-.. --- ...- . / -... .. --- .-.. --- --. -.-- / -.-. .-.. .- ...
.. .-.-.- / -- .-. .-.-.- / .... .- .-.. .-.. .. .... .- -. / .. ... / -.-- / ..-. .- ...- --- .-. .. - . / - . .- -.-. .... . .-. .-.-.-
DNA code
Does it mean anything?
ACACGCCTTAAGATC
GGTTTGCAGTAGATG
ATGTGCGGAATTCTAG
CCAAACGTCATCAGCT
A piece of DNA that contains a
code is known as a __________.
ACACGCCTTAAGATC
GGTTTGCAGTAGATG
ATGTGCGGAATTCTAG
CCAAACGTCATCAGCT
Genes contain the directions for
making __________.
Everyone’s codes are slightly different. This
means that different people make
____________ proteins.
Person 1
Person 2
Person 3
AAGTTCGCC
AAGTTCCCA
AAGGGCGCC
Person 4
AAGTTCGAA
Person 5
AAGTTTACC
 Proteins determine our looks, functions and
behavior and even how we are put together
while still inside our mothers!
Look at your protein research and classify
your protein into one of the categories on the
board. Write the name of the protein and a
brief function.
If proteins make up our body, and DNA
contains the code for proteins..
Person 1
Person 2
Person 3
AAGTTCGCC
AAGTTCCCA
AAGGGCGCC
Person 4
Person 5
AAGTTCGAA
AAGTTTACC
then differences in the bases would cause
differences in our bodies!
Example
Person 1
Person 2
CGGAAGTTAGCCTACATGC
CGGAAGTTCCCATACATGC
Gene
Gene
Different codes,
different proteins,
different eye colors
What is Gene Expression?
 All cells within an organism have the same
DNA, but not all genes are expressed.
Ex. An epithelial cell will express only genes
specific to skin, whereas a neuron cell will
express genes necessary for nerve function.
 Therefore, some genes are active and
making proteins (or expressed in some
cells) and some genes are inactive and not
making proteins
What is Gene Expression?
 Genes can be “turned
on” or “turned off” by
chemical signals in the
cell or chemical signals
from other cells, this is
known as:
cell to cell interaction.
How are proteins made?
PROTEIN SYNTHESIS
-the process cells use to make
protein from genes found within
the DNA
 Proteins are made in a part of the cell
known as the
_________________________.
 The _____________________ are found
outside of the nucleus in the
_______________________.
Proteins are made of amino acids
found in the cytoplasm.
(strung together like beads on a necklace)
DNA’s Helpers
 DNA never leaves the nucleus of the cell. It
is protected there.
 So how does the code get to the
ribosome??
DNA’s Helpers
 The DNA code can be copied to another
chemical known as RNA.
Types of RNA
 Messenger RNA
(mRNA)
– Copy of one gene
from DNA
– Carries the
message from the
DNA to the
ribosome
Types of RNA
• Transfer RNA (tRNA)
•Transports the amino acid
to the ribosome
Types of RNA
• Ribosomal
RNA (rRNA)
•Makes up the ribosome
• This is where the mRNA
will meet the tRNA to put
together the amino acids
Making Proteins
Copy the picture above
Step One = Transcription
Step Two = Translation
Transcription
1. DNA section with desired gene is unzipped by an
enzyme (the blue strands)
2. A complementary mRNA strand is made (red strand)
3. DNA is rezipped by an enzyme and mRNA moves into
the cytoplasm
Vocabulary
CODON –
3 letter sequence/”word” on mRNA
ANTI-CODON –
3 letter sequence on tRNA,
Translation
Blue thing = ribosome
Purple strand = mRNA
Yellow circles = tRNA
1.
Ribosome finds the first CODON of the gene on mRNA
Translation
2. tRNA’s anti-codon is matched up to mRNA
codon bringing the correlating amino acid
Translation
3. Ribosome moves
along mRNA and
continues to
match up tRNAs
4. Amino acids are bonded together to create a
chain of amino acids (a protein)
Scientists have learned which amino acid tRNA will bring
based on the mRNA codons.
By using the mRNA
codons, you can
determine the amino
acid order of the protein
using this chart.
Decoder Chart #1 –
How do determine what amino acid goes with the mRNA’s codon
CODON = AUG
Start in the center and work
your way out
A
U
G
Amino acid is methionine
Try finding the amino acid for the codon ‘CUA’
LEUCINE
Explain the photo
Here’s another look at the overall
process of PROTEIN SYNTHESIS