Transcript Transcription And Translation

Transcription And Translation
Melissa Snyder & Meghan Dunfee
Purpose for Flash of the Day!
• Helps students to understand how ideas
are connected.
• Reinforces learning through ownership.
• Prompts students to integrate prior
knowledge with new ideas.
April 20, 2001
What Is Transcription?
• Transcription means using DNA as a
template to make an RNA copy. Only one of
the DNA strands is used during the
transcription process. This strand is
referred to as the SENSE or TEMPLATE
strand. The complimentary DNA strand
that is not used is referred to as the
NONSENSE strand. Only a very small
part of the genome is copied.
April 20, 2001
What Will You Learn From
the Flash Video?
• The enzyme RNA polymerase synthesizes a
single strand of RNA using a double stranded
DNA molecule as it’s template.
• The binding of the RNA polymerase enzyme to
the DNA PROMOTOR SITE, starts the
process.
• Synthesis begins at a specific nucleotide
sequence called the START SIGNAL. This is
often found to be GTA on the DNA which
becomes CAU on the RNA molecule.
April 20, 2001
Transcription
A
T
G
U
A
C
C
G
T
A
G
A
U
G
C
C
April 20, 2001
C
A
• The RNA sequence
that is made is a
direct copy of the
bases in the sense
strand.
• DNA
RNA.
Guanine (G)
(C).
Cytosine (C)
(G).
Adenine (A)
(U).
cytosine
guanine
Uracil
Translation Library Elements!
What will we need for Translation to take
place?
• mRNA: the single strand of RNA
copied during transcription.
• Ribosome: reads the mRNA
• Amino acids
• Transfer tRNA: aa covalently bind to
and help to decode genetic material.
• ATP: source of energy
April 20, 2001
mRNA
http://www.brooklyn.cuny.edu/.html
April 20, 2001
• The mRNA taken from
the transcription
process is used.
• The initiation codon
codes for the
polypeptide and
usually begins with
AUG.
• At the end of this
coding region are stop
codons that act as
message terminators.
Ribosomes: Where Translation
Occurs
• Ribosomes use the mRNA as directions for
protein assembly.
• During protein synthesis, the ribosome moves
down the mRNA molecule and assembles
amino acids into the protein chain.
.
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tRNA
• Transfer RNA (tRNA) molecules
function as the "dictionary" in the
translation mechanism.
• Each tRNA molecule averages 76
nucleotides in length
tRNA
T
A
mRNA
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A
U
C
G
C
A
U
C
C
G
U
A
G
• The tRNA is capable of recognizing and
binding to the codon with it’s anti codon,
specifying its attached amino acid in an
mRNA molecule.
• At the end of the mRNA message, translation
stops, the ribosomal subunits, and the tRNA
separate and detach from the mRNA.
April 20, 2001
Acknowledgemen
Special Thanks to ts
Our Faculty Advisor!
April 20, 2001