Transcription is the process by which DNA is copied into messenger RNA (mRNA) by RNA polymerase. It involves unwinding the DNA double helix, synthesizing a complementary mRNA single strand according to the DNA template, and modifying the mRNA before it exits the nucleus. Unlike DNA replication, only a short segment of DNA is transcribed into mRNA at a time during transcription.

2. • The genetic information in DNA is not translated directly
into protien but is first transcribed into mRNA.
• Trancription involves numerious enzymes that unwind a
region of of a DNA molecule initiate and end mRNA
synthesis, and modify the mRNA after trancription is
complete.

3. • Unlike DNA replication only one or a few genes exposed
and only one of the two DNA strands is transcribed.
• RNA that is the result of transcription of DNA differ in the
nitrogenous base that is Urasil in the place of thymin from
the DNA that consist on thymin nitrogenious base.

5. • Definition Synthesis of RNA using ssDNA as a template
by DNA dependent RNA polymerase enzyme.
• Similar to replication in terms of chemical mechanism,
polarity, and use of template but differs in -does not
require primers -only a short segment of DNA is
transcribed DNA RNA Protein TRANSCRIPTION
TRANSLATION Nucleus

6. • All 3 types of cellular RNA’s are copied during
transcription
• Messenger RNAs (mRNAs) encode the amino acid
sequence of one or more polypeptides specified by a
gene.
• Transfer RNAs (tRNAs) read the information encoded in
the mRNA and transfer the appropriate amino acid to a
growing polypeptide chain during protein synthesis.

7. • Ribosomal RNAs (rRNAs) are constituents of ribosomes,
the intricate cellular machines that synthesize proteins.
• Ribonucleotides are used in RNA synthesis.

8. • RNA Synthesis occurs in 5’-3’ direction , DNA template is
read from 3’-5’ direction
• Synthesis follows Waston-Crick base pairing rules – A to
U, G to C
• DNA dependent RNA polymerase
• 5. • ss DNA Template •DNA dependent RNA polymerase
Enzyme • ATP, GTP,CTP,UTP ribonucleoside
triphosphates Basic Requirements of Transcription

9. • One of the important enzyme of this process is RNA
polymerase.
• After a section of DNA is unwound, RNA polymerase
recognizes a specific sequence of DNA nucleotides.
• RNA polymerase attaches and begine joining ribose
nucleotides which are complementary to the 3' end of the
DNA strand.

10. • In RNA the same complementary bases in DNA are paired
except that in RNA the base uracil replace the base thymine as a
compliment to adenine.
• Newly transcribed mRNA called the primary transcript must be
modified before leaving the nucleus to carry out protien
synthesis.

11. • RNA splicing involves cutting out noncoding regions so that
the mRNA coding region can be read continuously at the
ribosome.

12. • Initiation is the beginning of transcription.
• It occurs when the enzyme RNA polymerase binds to a region
of a gene called the promoter.
• This signals the DNA to unwind so the enzyme can ''read'' the
bases in one of the DNA strands.
• The enzyme is now ready to make a strand of mRNA with a
complementary sequence of bases.

13. • Transcription elongation is a regulated process in which an
RNA chain complementary to the template strand of DNA is
synthesized as RNA polymerase moves along DNA.
• Transcription elongation is preceded by transcription
initiation and is followed by transcription termination.

15. • RNA polymerase will keep transcribing until it gets signals
to stop.
• The process of ending transcription is called termination, and
it happens once the polymerase transcribes a sequence of
DNA known as a terminator.