1. TRANSCRIPTION
DNA mRNA

2. Transcribe means to make a copy …….copy a gene

3. DNA mRNA Transcription is the process of
copying a sequence of DNA (a gene)
in the form of mRNA.
DNA mRNA
transcription

4. RNA nucleic acid RNA, like DNA, is a ____________. nucleotides
RNA is also composed of ____________.
mRNA

5. RNA RNA differs from DNA in three ways:
RNA is single stranded . DNA is double stranded.
The sugar in RNA is ribose, whereas
the sugar in DNA is deoxyribose.
3. Both DNA and RNA contain four bases,
but RNA contains Uracil (U), not thymine (T)
Complementary base pairs in RNA are:
A --- U C --- G

6. Bases in DNA are:
A - Adenine
T - Thymine
C - Cytosine
G - Guanine
Base pairs in DNA are:
A --- T C --- G
T --- A G --- C
Bases in RNA are:
A - Adenine
U - Uracil
C - Cytosine
G - Guanine
Base pairs in RNA are:
A --- U C --- G
U --- A G --- C

7. There are three types of RNA:
mRNA
Messenger RNA--________ : a copy of a gene
that contains the instruction for making a protein.
rRNA
Ribosomal RNA-- _______:
ribosomes are made of rRNA
tRNA
Transfer RNA --_________:
It transports amino acids to the ribosome
so they can be assembled it proteins.

8. Overview TRANSCRIPTION DNA mRNA nucleus Copy of a gene mRNA DNA exits
the nucleus
T A A G C C T G A C G C T A T T
A T T C G G A C T G C G A T A A
DNA
gene

9. The steps in Transcription are:
1. RNA polymerase binds to the gene’s “start site”.
2. RNA polymerase unzips and separates the
two strands of DNA.
3. RNA polymerase adds and links RNA nucleotides
to one strand of DNA (DNA template).
As the mRNA strand grows, the two strands of DNA
close up reforming a double helix.
5. RNA nucleotides are added until a “stop” signal is reached.
mRNA strand detaches, exits the nucleus,
and enters the cytoplasm.

10. RNA polymerase binds to the gene’s “start site”. DNA Polymerase
nucleus
DNA Polymerase
DNA
T A A G C C T G A C G C T A T T
RNA polymerase
(an enzyme)
A T T C A G A C T G C G A T A A
start
DNA

11. RNA polymerase unzips and separates the two strands of DNA. nucleus
T A A G C C T G A C G C T A T T
A T T C A G A C T G C G A T A A
start
DNA

12. RNA polymerase adds and links RNA nucleotides to one strand of
DNA (DNA template).
nucleus A U G U C G
DNA
T A A G C C T G A C G C T A T T
mRNA
A T T C A G A C T G C G A T A A
start
DNA
DNA template

13. As the mRNA strand grows,
the two strands of DNA
close up reforming
a double helix.

14. “stop” signal is reached
RNA nucleotides
are added until a
“stop” signal is reached
nucleus A U G U C G
DNA
T A A G C C T G A C G C T A T T
mRNA
A T T C A G A C T G C G A T A A
stop

15. and enters the cytoplasm.
6. mRNA strand detaches,
exits the nucleus,
and enters the cytoplasm.
nucleus
DNA
T A A G C C T G A C G C T A T T
mRNA
mRNA G U C U G A
A T T C A G A C T G C G A T A A
stop

16. Let’s review
transcription!

17. RNA polymerase binds to the gene’s “start site”. RNA Polymerase
nucleus
RNA Polymerase
DNA
T A A G C C T G A C G C T A T T
RNA polymerase
(an enzyme)
A T T C A G A C T G C G A T A A
start
DNA

18. RNA polymerase unzips and separates the two strands of DNA. nucleus
T A A G C C T G A C G C T A T T
A T T C A G A C T G C G A T A A
start
DNA

19. RNA polymerase adds and links RNA nucleotides to one strand of
DNA (DNA template)
until stop signal.
nucleus A U G U C G
DNA
T A A G C C T G A C G C T A T T
A T T C A G A C T G C G A T A A
start
stop
DNA template

20. and enters the cytoplasm.
4. mRNA strand detaches,
exits the nucleus,
and enters the cytoplasm.
nucleus
DNA
T A A G C C T G A C G C T A T T
mRNA
mRNA G U C U G A
A T T C A G A C T G C G A T A A
stop

21. What is this process called? TRANSCRIPTION What is this? A DNA strand
The DNA template
What is this?
What is this?
mRNA
What is this?
RNA nucleotide
What is this
process called?
TRANSCRIPTION
What is this?
A DNA molecule