8.4 Transcription
A pairs with
U
Central Dogma
After the discovery of DNA's structure, Francis Crick defined the central dogma of biology, stating that information flows in one direction from DNA to RNA to proteins.
G pairs with
C
When do these processes occur in Eukaryotes?
In eukaryotic cells, DNA is located inside the nucleus so the processes are separated both in location and time.
2nd Step of Transcription
RNA polymerase uses a section of one strand of DNA as a template and strings together a complimentary strand of RNA. base pair rules are followed except Uracil (U) pairs with A instead of Thymine (T)
What template is used in Transcription?
A short segment of 1 strand of DNA
T pairs with
A
U pairs with
A
Pairs of Bases in RNA
A - U G - C
Bases of RNA
A Uracil C G
What template is used in DNA Replication?
All of each strand of DNA
What is RNA?
An intermediate molecule that takes the information coded by the DNA outside the nucleus to the ribosome where a protein can be made.
Transcription
Converts DNA into RNA
Replication
Copies DNA
What is made in DNA Replication?
DNA
What enzyme is used in DNA Replicatio?
DNA Polymerase, DNA Helicase
Who defined the central dogma?
Francis Crick
C pairs with
G
When do these processes occur in Prokaryotic cells?
In prokaryotic cells, all 3 processes occur in the cytoplasm at approximately the same time.
Translation
Interprets RNA message to make string of amino acids (polypeptide), which makes a protein.
3 Types of RNA
Messenger RNA - mRNA Ribosomal RNA - rRNA Transfer RNA - tRNA
Transcription
Process of copying a sequence of DNA to produce a complimentary set of RNA
What is made in transcription?
RNA
How does RNA differ from DNA?
RNA has one strand of nucleotides, DNA has 2 strands. RNA has a 5-Carbon sugar, ribose, which has one more oxygen atom than Deoxyribose in DNA RNA nucleotides use the nitrogen-base Uracil (U) instead of Thymine.
What enzyme is used in Transcription?
RNA polymerase
1st Step of Transcription
RNA polymerase recognizes the transcription start site of a gene and unwinds the DNA segment
3rd Step of Transcription
RNA strand detaches from the DNA after it has been transcriped and the DNA helix recoils.
Eukaryotic cells - where do these processes each take place
Replication and transcription occur in the nucleus, while translation occurs in the cytoplasm.
3 Processes
Replication, Transcription, Translation
RNA abbreviated for
Ribonucleic acid
Codon
a series of three-nucleotide sequences that correspond to an amino acid, start or stop signal for translation.
RNA polymerase
an enzyme that bonds nucleotides together in a chain to make a new RNA molecule
mRNA
an intermediate message that is translated to form a protein. Instructions are written as codons
tRNA
brings amino acids from the cytoplasm to a ribosome to make a protein.
Translation occurs in the
cytoplasm
rRNA
forms part of the ribosomes
Replication occurs in the
nucleus
Transcription occurs in the
nucleus