What do you think Strange huh Transcription amp Translation Overview Transcription Translation DNA RNA Protein Characteristics Make Short Notes Transcription amp Translation ID: 587134
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Slide1
What do you Think?Slide2
What do you think?Slide3
Strange huh?Slide4
Transcription & TranslationSlide5
Overview
Transcription Translation
DNA
RNA
Protein
CharacteristicsSlide6
Make Short Notes
Transcription & TranslationSlide7
Transcription
DNA never leaves the nucleus
Proteins are synthesized in the cytoplasm
Therefore a copy of the each gene is made using messenger RNA to carry the message from Nucleus to the Cytoplasm
Transcription
Is the synthesis of an RNA molecule with a base pair complementary to a section of DNASlide8
Transcription
Usually only a small part of the DNA molecule is transcribed at one time – a section that codes for making one polypeptide is called a
GENE
The process starts by the unzipping of the DNA Helix by the enzyme
DNA
Helicase
which break the H
+
bonds
Free RNA nucleotides slot into place against the DNA strand i.e. A-U, G-C
Temporary
H+ bonds results to hold the RNA in place and Phosphodiester
bonds are created between the RNA nucleotidesSlide9
Transcription
This process is catalyzed by the enzyme
RNA polymerase
this also ensures that the sequence of amino acids is correct
This elongation of the mRNA continues until the end of the gene or until a
STOP
codon
(ATT, ATC, ACT) is reached
The DNA may zip back up and the mRNA strand exits the nucleus via the nuclear pore into the cytoplasmSlide10
Translation
Translation
is the process by which the code for making proteins (carried by the mRNA) is used to sequence a polypeptide chain
The sequence of
codons
is carried on the mRNA
The AUG (
Methionine
)
codon
indicates the start of an amino acid sequence
The mRNA is held in a cleft in the ribosome in the cytoplasm Slide11
Translation
A
tRNA
complementary to the 1
st
start
codon
binds to the mRNA
(INITIATION)
Each
tRNA
carries with it a corresponding amino acidAs the triple
codons are read, complementary tRNA molcecules with their amino acids bind to the mRNAUpon completion , each
tRNA molecule breaks free leaving behind its corresponding amino acidSlide12
Translation
Peptide bonds form between the amino acids resulting in elongation of the polypeptide
The released
tRNA
is now available to be reloaded with its complementary amino acid
The polypeptide build up until a STOP
codon
is reached on the mRNA
(TERMINATION)Slide13
ANSWERS
ACTIVITY 1
TACCGGGTGTACGGGGTG
DNA Coding Strand
AUGGCCCACAUGCCCCAC
mRNA Strand
met ala
hist
met pro
hist
Polypeptide Sequence
N.B. The anticodons on the tRNA
are complementary to the codons on the mRNASlide14
Answers
Assessment
Stage A:
Transcription
Stage B:
Translation
Outline the Process occurring at Stage A:
It Is
the synthesis of an
mRNA
molecule with a base pair
complementary to a section of DNA. Usually only a small part of the DNA molecule is transcribed at one time .
The process starts by the unzipping of the DNA Helix by the enzyme DNA Helicase which break the H+ bonds.
Free RNA nucleotides slot into place against the DNA strand. Slide15
Answers
Assessment cont’d
Temporary
H
+
bonds
results to hold the RNA in place and
Phosphodiester
bonds
are created between the RNA nucleotides.
This process is catalyzed by the enzyme RNA polymerase this also ensures that the sequence of amino acids is correct. This elongation of the mRNA continues until the end of the gene or until a
STOP codon (ATT, ATC, ACT) is reached. The DNA may zip back up and the mRNA strand exits the nucleus via the nuclear pore into the cytoplasmSlide16
THE END
Thank You