transcription
TRANSCRIPTION
Submitted To: Ma’am Shumaila Nadeem
Submitted By: Zinnia Shah
Date of Submission: Sep’25th-2014
KINNAIRD COLLEGE for WOMEN
CONTENTS
Introduction to transcription in eukaryotic cells -RNA-polymerases -promoters -outline of steps involved in transcription -transcription factors -basal-transcription-apparatus and the upstream-factors -Inducible factors
Transcription in detail -Initiation -Elongation -Termination
An over-view
References
INTRODUCTION TO ‘TRANSCRIPTION’: (with reference to eukaryotic cells)
Transcription literally means “the act or process of making a copy.” In genetics, it refers to the copying of a DNA sequence into an RNA sequence. This process is the first step in gene expression (Gene: a segment of DNA used to make a functional product – either RNA or a polypeptide). Transcription of a structural gene produces messenger RNA (m.RNA).
We can also say that; Transcription is the mechanism by which the base sequence of a section of DNA representing a gene is converted into the complementary base sequence of mRNA. For this to happen, the DNA double helix structure unwinds hence exposing the inner bases. Out of these two strands , one of them is selected against which the complementary single strand of RNA forms , this strands is termed as the ‘template’ strand i.e. the strand that is actually transcribed
This process was first demonstrated by using synthetic DNA composed solely of the thymine nucleotides i.e. (TTT) , when introduced into a cell free system , containing all other four nucleotides ( A, C, U and G ) and RNA polymerases. The m.RNA strand was formed which was composed entirely of adenine (AAA) nucleotides. This experiment also gave us the knowledge about the
Submitted To: Ma’am Shumaila Nadeem
Submitted By: Zinnia Shah
Date of Submission: Sep’25th-2014
KINNAIRD COLLEGE for WOMEN
CONTENTS
Introduction to transcription in eukaryotic cells -RNA-polymerases -promoters -outline of steps involved in transcription -transcription factors -basal-transcription-apparatus and the upstream-factors -Inducible factors
Transcription in detail -Initiation -Elongation -Termination
An over-view
References
INTRODUCTION TO ‘TRANSCRIPTION’: (with reference to eukaryotic cells)
Transcription literally means “the act or process of making a copy.” In genetics, it refers to the copying of a DNA sequence into an RNA sequence. This process is the first step in gene expression (Gene: a segment of DNA used to make a functional product – either RNA or a polypeptide). Transcription of a structural gene produces messenger RNA (m.RNA).
We can also say that; Transcription is the mechanism by which the base sequence of a section of DNA representing a gene is converted into the complementary base sequence of mRNA. For this to happen, the DNA double helix structure unwinds hence exposing the inner bases. Out of these two strands , one of them is selected against which the complementary single strand of RNA forms , this strands is termed as the ‘template’ strand i.e. the strand that is actually transcribed
This process was first demonstrated by using synthetic DNA composed solely of the thymine nucleotides i.e. (TTT) , when introduced into a cell free system , containing all other four nucleotides ( A, C, U and G ) and RNA polymerases. The m.RNA strand was formed which was composed entirely of adenine (AAA) nucleotides. This experiment also gave us the knowledge about the