Download - Rna and protein synthesis
RNA ANDRNA AND PROTEIN PROTEIN
SYNTHESISSYNTHESIS
By By Muhammad AsifMuhammad AsifPu PakPu Pak
Muhammad Asif PuMuhammad Asif Pu
How your cell makes very important How your cell makes very important proteinsproteins
The production (synthesis) of proteinsproteins.3 phases3 phases:
1.1. TranscriptionTranscription
2.2. RNA processingRNA processing
3.3. TranslationTranslation
DNA DNA RNA RNA ProteinProtein
Muhammad Asif PuMuhammad Asif Pu
DNA DNA RNA RNA ProteinProtein
Nuclearmembrane
TranscriptionTranscription
RNA ProcessingRNA Processing
TranslationTranslation
DNA
Pre-mRNA
mRNA
Ribosome
Protein
Eukaryotic Eukaryotic CellCell
Muhammad Asif PuMuhammad Asif Pu
Before making proteins, Your cell Before making proteins, Your cell must first make RNAmust first make RNA
Question:Question:How does RNARNA (ribonucleic acid) (ribonucleic acid) differ
from DNA (deoxyribonucleic acid)DNA (deoxyribonucleic acid)?
Muhammad Asif PuMuhammad Asif Pu
RNARNA differs from DNADNA
1. RNARNA has a sugar ribosesugar ribose
DNADNA has a sugar deoxyribosesugar deoxyribose
2. RNARNA contains uracil (U)uracil (U)
DNADNA has thymine (T)thymine (T)
3. RNARNA molecule is single-strandedsingle-stranded
DNADNA is double-strandeddouble-stranded
Muhammad Asif PuMuhammad Asif Pu
Muhammad Asif PuMuhammad Asif Pu
1. Transcription1. Transcription
Nuclearmembrane
TranscriptionTranscription
RNA ProcessingRNA Processing
TranslationTranslation
DNA
Pre-mRNA
mRNA
Ribosome
Protein
Eukaryotic Eukaryotic CellCell
Muhammad Asif PuMuhammad Asif Pu
1. Transcription OR1. Transcription OR RNA production RNA production
RNA molecules are produced by copying part of DNA into a complementary sequence of RNA
This process is started and controlled by an enzyme called RNA polymerase.
Muhammad Asif PuMuhammad Asif Pu
1. Transcription1. Transcription
DNADNA
pre-mRNApre-mRNA
RNA PolymeraseRNA Polymerase
Muhammad Asif PuMuhammad Asif Pu
Question:Question:
What would be the complementary RNARNA strand for the following DNADNA sequence?
DNA 5’-GCGTATG-3’DNA 5’-GCGTATG-3’
Muhammad Asif PuMuhammad Asif Pu
Types of RNATypes of RNA
Three types ofThree types of RNARNA:
A.A. messenger RNA (mRNA)messenger RNA (mRNA)
B.B. transfer RNA (tRNA)transfer RNA (tRNA)
C.C. ribosome RNA (rRNA)ribosome RNA (rRNA)
Remember: all produced in theRemember: all produced in the nucleusnucleus!!
Muhammad Asif PuMuhammad Asif Pu
mRNA
Carries instructions from DNA to the rest of the ribosome.
Tells the ribosome what kind of protein to make
Acts like an email from the principal to the cafeteria lady.
Muhammad Asif PuMuhammad Asif Pu
A. Messenger RNA (mRNA)A. Messenger RNA (mRNA)
methionine glycine serine isoleucine glycine alanine stopcodon
proteinprotein
A U G G G C U C C A U C G G C G C A U A AmRNAmRNA
startcodon
Primary structure of a proteinPrimary structure of a protein
aa1 aa2 aa3 aa4 aa5 aa6
peptide bonds
codon 2 codon 3 codon 4 codon 5 codon 6 codon 7codon 1
Muhammad Asif PuMuhammad Asif Pu
If the cell is a school…If the cell is a school…
The Nucleus is the school officeThe Nucleus is the school officeThe Nucleolus is the principal’s The Nucleolus is the principal’s
officeofficeThe DNA is the principalThe DNA is the principalRibosomes are the cafeteria Ribosomes are the cafeteria
ladiesladiesmRNA is the email from the mRNA is the email from the
principal to the cafeteria ladyprincipal to the cafeteria ladyMuhammad Asif PuMuhammad Asif Pu
rRNA
Part of the structure of a ribosomeHelps in protein production
tRNA
A go-getter. Gets the right parts to make the right protein according to mRNA instructions
Muhammad Asif PuMuhammad Asif Pu
B. Transfer RNA (tRNA)B. Transfer RNA (tRNA)
amino acidamino acidattachment siteattachment site
U A C
anticodonanticodon
methionine amino acidamino acid
Muhammad Asif PuMuhammad Asif Pu
2. RNA Processing2. RNA Processing
Nuclearmembrane
TranscriptionTranscription
RNA ProcessingRNA Processing
TranslationTranslation
DNA
Pre-mRNA
mRNA
Ribosome
Protein
Eukaryotic Eukaryotic CellCell
Muhammad Asif PuMuhammad Asif Pu
2. RNA Processing2. RNA Processing
IntronsIntrons are pulled out and exonsexons come together.
End product is a mature RNA mature RNA moleculemolecule that leaves the nucleusnucleus to the cytoplasm.cytoplasm.
Introns bad…… Exons good!Introns bad…… Exons good!
Muhammad Asif PuMuhammad Asif Pu
2. RNA Processing2. RNA Processing
pre-RNA molecule
intron
intronexon exon exon
exon exon exon
Mature RNA moleculeMature RNA molecule
exon exon exon
intron intron
splicesome splicesome
Muhammad Asif PuMuhammad Asif Pu
RibosomesRibosomes
PSite
ASite
Largesubunit
Small subunit
mRNAmRNA
A U G C U A C U U C G
Muhammad Asif PuMuhammad Asif Pu
3. Translation - making proteins3. Translation - making proteins
Nuclearmembrane
TranscriptionTranscription
RNA ProcessingRNA Processing
TranslationTranslation
DNA
Pre-mRNA
mRNA
Ribosome
Protein
Eukaryotic Eukaryotic CellCell
Muhammad Asif PuMuhammad Asif Pu
3. Translation3. Translation
Three parts:1. initiationinitiation: start codon (AUG)2. elongationelongation:3. terminationtermination: stop codon (UAG)
Let’s make a PROTEIN!!!!PROTEIN!!!!.
Muhammad Asif PuMuhammad Asif Pu
3. Translation3. Translation
PSite
ASite
Largesubunit
Small subunit
mRNAmRNA
A U G C U A C U U C G
Muhammad Asif PuMuhammad Asif Pu
InitiationInitiation
mRNAmRNA
A U G C U A C U U C G
2-tRNA
G
aa2
A U
A
1-tRNA
U A C
aa1
anticodon
hydrogenbonds codon
Muhammad Asif PuMuhammad Asif Pu
mRNAmRNA
A U G C U A C U U C G
1-tRNA 2-tRNA
U A C G
aa1 aa2
A UA
anticodon
hydrogenbonds codon
peptide bond
3-tRNA
G A A
aa3
ElongationElongation
Muhammad Asif PuMuhammad Asif Pu
mRNAmRNA
A U G C U A C U U C G
1-tRNA
2-tRNA
U A C
G
aa1
aa2
A UA
peptide bond
3-tRNA
G A A
aa3
Ribosomes move over one codon
(leaves)
Muhammad Asif PuMuhammad Asif Pu
mRNAmRNA
A U G C U A C U U C G
2-tRNA
G
aa1
aa2
A UA
peptide bonds
3-tRNA
G A A
aa3
4-tRNA
G C U
aa4
A C U
Muhammad Asif PuMuhammad Asif Pu
mRNAmRNA
A U G C U A C U U C G
2-tRNA
G
aa1aa2
A U
A
peptide bonds
3-tRNA
G A A
aa3
4-tRNA
G C U
aa4
A C U
(leaves)
Ribosomes move over one codonMuhammad Asif PuMuhammad Asif Pu
mRNAmRNA
G C U A C U U C G
aa1aa2
A
peptide bonds
3-tRNA
G A A
aa3
4-tRNA
G C U
aa4
A C U
U G A
5-tRNA
aa5
Muhammad Asif PuMuhammad Asif Pu
mRNAmRNA
G C U A C U U C G
aa1aa2
A
peptide bonds
3-tRNA
G A A
aa3
4-tRNA
G C U
aa4
A C U
U G A
5-tRNA
aa5
Ribosomes move over one codonMuhammad Asif PuMuhammad Asif Pu
mRNAmRNA
A C A U G U
aa1
aa2
U
primaryprimarystructurestructureof a proteinof a protein
aa3
200-tRNA
aa4
U A G
aa5
C U
aa200
aa199
terminatorterminator or stopor stop codoncodon
TerminationTermination
Muhammad Asif PuMuhammad Asif Pu
End ProductEnd Product
The end products of protein synthesis is a primary structure of a proteinprimary structure of a protein.
A sequence of amino acid amino acid bonded together by peptide bondspeptide bonds.
aa1
aa2 aa3 aa4aa5
aa200
aa199
Muhammad Asif PuMuhammad Asif Pu
Question:Question:
The anticodon The anticodon UACUAC belongs to a belongs to a tRNAtRNA that recognizes and binds to a that recognizes and binds to a particular particular amino acidamino acid..
What would be the What would be the DNA base code DNA base code for for this this amino acid?amino acid?
Muhammad Asif PuMuhammad Asif Pu
Answer:Answer:
tRNA tRNA - UAC - UAC (anticodon)(anticodon)
mRNAmRNA - AUG (codon)- AUG (codon)DNA DNA - TAC- TAC
Muhammad Asif PuMuhammad Asif Pu