Download 2017 Lecture 10, student version

RNA
Transcription and Translation
How is information in DNA used
to make protein?
RNA acts as ____________________
DNA and protein synthesis machinery
Transcription - copying of ___________
__________________________
Translation - production of __________
__________________________
Whole process = _________________
DNA (gene)
RNA
Protein
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RNA
Ribonucleic Acid
dAMP DNA uses _______________
RNA uses _______________
In RNA uracil is used instead __________________________
AMP
UMP
GMP
CMP
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RNA
Ribonucleic Acid
Formation of sugar-phosphate backbone
As with DNA:
- Individual nucleotides are connected
through linking the ______________
____________ with the phosphate group
on the __________________________
Single strand of polynucleotides
- RNA has directionality, 5’ - 3’
5’ - A C G U - 3’
5’ end = start of gene
3’ end = end of gene
Ultimately -5’ end of RNA (gene) = _______________
-3’ end of RNA (gene) = _______________
Unlike DNA:
RNA is ____________________, __________________
__________________
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RNA
Ribonucleic Acid
single stranded RNA
can fold and _____ and _____ will H-bond forming
base pairs
H-bonding
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RNA
Ribonucleic Acid
Six kinds of RNA
transfer RNA (tRNA) - carries _____________________ during
ribosomal RNA (rRNA)
protein synthesis
messenger RNA (mRNA) - is ___________________
- encodes ______________
small nuclear RNA (snRNA)
micro RNA (miRNA)
small interfering RNA (siRNA)
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Transcription
Central dogma of molecular biology
DNA (gene)
RNA
Protein
Transcription:
the synthesis of ____________________________
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Transcription
RNA polymerase – reads _________________________________
- ___________________ of DNA in 3’ - 5’ direction
- resulting RNA is ________________________
- resulting RNA is same as ___________________
Transcription
http://www.youtube.com/watch?v=Jqx4Y0OjWW4&feature=related
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Transcription
mRNA (messenger RNA) - the RNA produced from _____________
- is used for ____________________
- is capped at _______________
- is capped at ________________________
_______________________________
- both caps help ________________________
5’
3’
AAAAAAAAAAAAAA
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Translation
Central dogma of molecular biology
DNA (gene)
RNA
Protein
Transcription:
the synthesis of RNA based on DNA sequence
Translation:
Synthesis of protein from RNA template
Players in translation:
- mRNA
- ____________
- ____________
- ____________
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Translation
Steps of translation:
- _____________
- _____________
- _____________
How to read the sequence of mRNA?
How does the sequence of mRNA
translate into protein sequence?
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Translation
The genetic code
Genetic code is:
- _______________________________
code for one amino acid
- _____________________
- continuous, ________________
__________________________
- universal, ___________________
____________________
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Translation
Codon - triplet of nucleotide bases _____________________________
Since 4 different nucleotide bases (A T (U) G C ) there are
_______________________________
There are 20 different amino acids
- ______________________________ for a single amino acid
DNA sequence:
ATG TTT TCT CCG AAT AGC GGT TGA
transcription
mRNA sequence:
___ ___ ___ ___ ___ ___ ___ ___
translation
___ ___ ___ ___ ___ ___ ___ ____
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Why multiple Codons for single amino acid?
DNA sequence:
ATG TTT TCT CC_ AAT AGC GGT TGA
transcription
mRNA sequence:
AUG UUU UCU CC_ AAU AGC GGU UGA
translation
Met Phe Ser ___ Asn Ser Gly stop
Mutation in DNA:
ATG TTT TCA CC_ AAT AGC GGT TGA
transcription
mRNA sequence:
Multiple codons______
___________________
___________________
___________________
___________________.
AUG UUU UCA CC_ AAU AGC GGU UGA
translation
Met Phe Ser ___ Asn Ser Gly stop
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Cracking the genetic code
Marshall Warren Nirenberg
(1927-2010)
- American born biochemist
- Worked at National Institutes of Health (NIH)
- Genetic code experiments in early 1960’s.
- Definitive experiment in 1964
- Nobel prize in physiology or medicine 1968
Har Gobind Khorana (1922-2011)
- born in what is now Pakistan, biochemist
- worked at Univ. Wisconsin - Madison
- Nobel prize in physiology or medicine 1968 with Nirenberg
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Translation
How to convert mRNA sequence into protein?
Process requires many different proteins and other factors.
Two main players:
Ribosome - a cellular structure that catalyses the __________________
_______________________________________
transferRNA (tRNA) - small RNA which binds to and carries single
amino acids to __________________________
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Translation
1. Initiation: Ribosome binds to mRNA and moves along until it recognizes
_____________________________________
2. tRNA with bound amino acid binds to mRNA codon.
- anticodon: - __________________________
- the complement ____________
3. Elongation: Next tRNA binds to _______________________________
4. Ribosome moves on to next codon, process repeats
Met
Phe
Ser
Pro
Asn
Ser
5. Termination: polypeptide chain is terminated when ____________________________
______________________________
Met
5’
Phe
Ser
AAA AGA
3’
XXX AUG UUU UCU CCG AAU AGC GGU UGA AAAAAAAAAAAAAA
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Gly
tRNA Discovery
Robert W. Holley (1922-1993)
- American born biochemist
- worked at Cornell University
- finalized the structure of tRNA in 1964
- awarded Nobel prize in physiology or medicine 1968
along with Nirenberg and Khorana
Translation movie:
http://www.youtube.com/watch?v=5bLEDd-PSTQ&feature=related
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tRNA Discovery
Robert W. Holley
- American born biochemist
- worked at Cornell University
- finalized the structure of tRNA in 1964
- awarded Nobel prize in physiology or medicine 1968
along with Nirenberg and Khorana
Translation movie:
http://www.youtube.com/watch?v=5bLEDd-PSTQ&feature=related
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The Big Picture - what have we studied so far?
Historically,
this is the path of
determining the
______________
_______________
How to go from
DNA base pair
sequence
to protein amino
acids sequence.
Proteins:
- 1˚, 2˚, 3˚, 4˚ structure
- fibrous proteins
- globular proteins
- purification/analysis techniques
- enzyme kinetics
- mechanisms of enzyme control
DNA:
- structure
- replication
Transcription:
- RNA polymerase
- mRNA production
Translation:
- Ribosome
- tRNA
- a.a.’s linked to make
protein
Amino acids:
- structure
- acid/base properties
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- peptide bond