Transcription
Transcription uses the information in a
single gene in the DNA to make a
messenger RNA (mRNA) molecule. DNA
is a polymer of four types of
nucleotides, G, C, A and T, and RNA is a
polymer of four corresponding types of
nucleotides, G, C, A and U (Uracil
instead of Thymine!).
During transcription, the enzyme, RNA
polymerase, separates the two strands
of DNA and makes the mRNA molecule
by adding RNA nucleotides, one at a
time. Each RNA nucleotide is joined to the previous nucleotide by a covalent bond.
Each DNA nucleotide in the gene is matched by a complementary RNA nucleotide which has a matching shape
and charge distribution. The base-pairing rules summarize which pairs of the strands are complimentary. The
base-pairing rules for transcription are very similar to the base-pairing rules in the DNA double helix. The basepairing rules ensure that the message from the nucleotide sequence in the gene in the DNA is copied into a
corresponding nucleotide sequence in the mRNA molecule.
DNA replication
Transcription
The whole chromosome is replicated.
Just one gene is transcribed.
DNA is made.
________ is made.
DNA is double-stranded.
mRNA is _________-stranded.
DNA polymerase is the enzyme which carries out DNA
replication.
________ _______ is the enzyme which carries
out transcription.
T = thymine is used in DNA,
T = thymine is replaced by ____ = ________ in
RNA,
so A pairs with T in DNA.
so A in DNA pairs with ___ in mRNA.