Download pre RNA lecture

Sense Strand of DNA:
CCAGTATACCCGAGTACCCCGCAGGAGCACCAGGAATTCCGCCATACACGCCCATCCCCACTCGAAAAAAAAAA
Poly-a-tail
TATA box
Termination region,
site where
transcription ends,
the end of a gene.
Promoter region, the site
where transcription
begins, the start of a
gene.
Primary mRNA or preRNA:
Intron
Exon
Intron
Exon
Intron
I--------------------I------------------------------------------------I-----------------I--------------------------I------------------------------------AUAUGGGCUCAUGGGGCGUCCUCGUGGUCCUUAAGGCGGUAUGUGCGGGUAGGGGUGAGCUUUUUUUUUU
Stop Codon
Start Codon
Tells the ribosome to
start making a protein
Stop Codon
Start Codon
Tells the ribosome to stop
making a protein
Mature mRNA
Exon
Exon
I-----------------------------------------------I---------------------------------I
AUGGGGCGUCCUCGUGGUCCUUAAAUGUGCGGGUAG
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New vocabulary:
Gene: has code for making 1 or more proteins.
TATA box: code on DNA that tells mRNA to start
the process of transcription. The start of a gene.
Poly A tail: code on DNA that tells mRNA to stop
the process of transcription. The end of a gene.
AUG: code on mRNA that tells the ribosome to
start making a protein
UAA, UAG, UGA: code on mRNA that tells the
ribosome to stop making a protein
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Sense Strand of DNA:
CCAGTATACCCGAGTACCCCGCAGGAGCACCAGGAATTCCGCCATACACGCCCATCCCCACTCGAAAAAAAAAA
Poly-a-tail
TATA box
Termination region,
site where
transcription ends,
the end of a gene.
Promoter region, the site
where transcription
begins, the start of a
gene.
Primary mRNA or preRNA:
Intron
Exon
Intron
Exon
Intron
---------------------I------------------------------------------------I-----------------I--------------------------I------------------------------------AUAUGGGCUCAUGGGGCGUCCUCGUGGUCCUUAAGGCGGUAUGUGCGGGUAGGGGUGAGCUUUUUUUUUU
Start Codon
Stop Codon Start Codon Stop Codon
Mature mRNA
Exon
Exon
I-----------------------------------------------I---------------------------------I
AUGGGGCGUCCUCGUGGUCCUUAAAUGUGCGGGUAG
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Exon: mRNA that codes for one protein, it is
the segment that will be EXPRESSED
Intron: noncoding segments of mRNA that
does not code for a protein, it is mRNA that
copied junk DNA. It will be SLICED out
Only the exons are taken to the ribosomes,
so the ribosome only reads mRNA that
codes for amino acids and nothing else.
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Sense Strand of DNA:
CCAGTATACCCGAGTACCCCGCAGGAGCACCAGGAATTCCGCCATACACGCCCATCCCCACTCGAAAAAAAAAA
TATA Box
Poly-a-tail
Promoter Region
Termination Region
Site where transcription begins
Site where transcription ends.
Start of a gene
End of gene
Primary mRNA:
Intron
Exon
Intron
Exon
Intron
I------------------I------------------------------------------------I------------I-----------------------I-------------------------------------I
AUAUGGGCUCAUGGGGCGUCCUCGUGGUCCUUAAGGCGGUAUGUGCGGGUAGGGGUGAGCUUUUUUUUUU
Start codon
Tells ribosome to
start making protein
Stop codon
Start codon
Stop codon
Tells ribosome to
stop making protein
Mature mRNA:
Exon
Exon
I-----------------------------------------------I-----------------------I
AUGGGGCGUCCUCGUGGUCCUUAAAUGUGCGGGUAG
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Mature mRNA:
Exon
Exon
I-----------------------------------------------I-----------------------I
AUG/GGG/CGU/CCU/CGU/GGU/CCU/UAA/AUG/UGC/GGG/UAG
Protein 1
Protein 2
Finally, mature mRNA is prepared by adding
a protective cap to each end to protect it
from harmful enzymes in a cells cytoplasm.
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DNA Codon
mRNA
codon
tRNA
anticodon
Amino Acid
AAA
UUU
AAA
PHENYL
GTC
GGA
GLYCINE
METH/START
GAT
GUG
VALINE
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CHNOPS LAB
DNA: TAC AGG GCG ATT
mRNA:____________________
tRNA:______________________
Amino Acid sequence: ____________________________________
Trait: _____________________
AMINO ACID SEQUENCE
TRAIT
Methionine-threonine-glycine-tyrosine-
Hairless
Methionine- threonine-glycine-glycine
Hairy
Methionine- threonine-proline-proline
Plump
Methionine- tyrosine-glycine-lysine
Skinny
Methionine-serine-arginine
Four-eyed
Methionine-serine-tyrosine
Two-eyed
Methionine-glycine-arginine-lysine-proline
Long nose
Methionine- proline-arginine-lysine-proline
Short nose
Methionine-phenylalanine-lysine
No freckles
Methionine- phenylalanine-asparagine
Freckles
Methionine- glycine-arginine-arginine
Blue skin
Methionine- glycine-arginine-phenylalanine
Orange skin
Methionine-isoleucine-isoleucine-leucine
Male
Methionine-isoleucine-isoleucine-glycine
Female
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Processing pre-mRMA into mature mRNA:
1. Cut out sections 1-3 of DNA and tape
together in order.
Section 1
C
G
G
C
T
A
A
T
Section 2
T
A
T
A
T
A
Section 3
A
A A
T
T T
G
C
C
G
A
T
A
T
A
T
T
A
A
T
C
G
G
C
A
T
A
T
T
A
T
A
A
T
A
T
A
T
T
A
A
T
T
A
C
G
A
T
T
A
G
C
A
T
C
G
C
G
T
A
A
T
A
T
T
A
C
G
A
T
T
A
C
G
G
C
A
T
A
T
T
A
A
T
G
C
A
T
T
A
T
A
C
G
C
G
A
T
C
G
T
A
G
C
G
C
G
C
T
A
A
T
A
T
T
A
T
A
T
A
G
C
T
A
T
A
C
G
A
T
G
C
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2. Locate the beginning of the gene on the
sense side of DNA (Top line) and
underline it.
How?
TATA Box
3. Locate the end of the gene on the
sense side of DNA and underline it.
How?
poly-A-tail
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4. Act like RNA polymerase…..
How?
Use your scissors to cut apart
the sense and antisense sides of DNA
beginning at the end of the TATA and
going to the beginning of the poly-A-tail.
Section 1
C
G
T
A
G
A
T
A
T
A
G
C
A
T
C
T
A
T
A
T
A
T
A
T
A
T
G
C
T
T
A
C
A
T
G
A
C
A
T
G
A
A
T
T
C
C
G
A
A
T
G
T
A
C
T
G
T
A
C
T
T
A
A
G
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5. Number the DNA nucleotides 1-54 (start at
end of TATA and to the beginning of the polya-tail.
6. Put in slashes, dividing it into 3’s or
codons.
Section 1
C
G
T
A
G
A
T
A
T
A
G
C
A
T
C
T
A
T
A
T
A
T
A
T
A
T
G
C
T
T
A
C
A
T
G
A
C
A
T
G
A
A
T
T
C
C
G
A
A
T
G
T
A
C
T
G
T
A
C
T
T
A
A
G
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7. Cut out the two sections of pre-RNA and tape
together. Put in slashes, dividing it into 3’s or
codons.
8. Complete the process of transcription.
How?
You now have just made pre-mRNA
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9. Locate the beginning of a protein.
How?
Start codon
AUG
10.Locate the end of a protein.
How?
Stop codon
UAA
UAG
UGA
11. Locate the next set of start and stop
codons.
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12.Label the introns and exons.
Introns:
Non coding
Exons:
Express……codes for a protein
13.Cut out the introns.
14.Tape together the exons.
15.Add a protective 5’ cap to the front and
a protective poly-A-tail tail to the end.
These protect the mature mRNA from
harmful enzymes in the cytoplasm.
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