Central Dogma (Lec) Flashcards
The Central Dogma of Molecular Biology
DNA Replication - Transcription (/Reverse Transcription) - RNA Replication - Translation - Protein
the process of making copies of genetic
information, converting information in DNA into
RNA, and then RNA into proteins
The Central Dogma
of Molecular
Biology
making copies of genetic information
Replication
conversion of DNA to RNA.
Transcription
conversion of RNA to DNA;
viruses only
Reverse Transcription
conversion of mRNA into a protein;
protein synthesis
Translation
Nucleotide sequences that carry
specific instructions for the cell,
usually for protein synthesis
GENES
Smallest hereditary unit; smallest
form of genetic information passed
from parent to offspring
GENES
T/F - A single strand of DNA can carry multiple genes.
T
Genes: Prokaryotes vs Eukaryotes
- In prokaryotes, the
entire gene codes for a
protein/molecule. - In eukaryotes, the gene
consists of coding
(exons) and non-coding
(introns) regions.
Introns are removed and exons are joined together at the end of transcription to form the final mRNA product via a process called?
RNA splicing
Only what percentage of human DNA actually codes for proteins, while non-coding regions still play a role
3%
highly repetitive, non-coding DNA sequences in which longer
ones provide structural stability to chromosomes
Satellites
shorter repeats, and are used to
monitor mutations implicated in diseases, such as cancer
Mini-satellites and microsatellites
DNA Replication occurs in what manner?
semi-conservative manner where DNA strands of the parent DNA becomes the template for the daughter strands.
What is the benefit of the said manner?
It is fast, accurate, and allows for easy repair of DNA. It is also responsible for phenotypic diversity in a few prokaryotic species.
T/F - Replication occurs on both strands of the DNA.
T
strand running from 3’ to 5’ towards the fork is called?
leading strand
strand running from 5’ to 3’ towards the fork is called?
lagging strand
DNA Replication begins at?
origin of replication (a chromosome can have multiple origins)
where replication actively occurs
replication fork
The assembly of proteins that facilitate DNA replication is called the?
replisome
The opening in the DNA where replication takes place is generally called the?
replication bubble
THE REPLISOMES (7):
- DNA Gyrase/Topoisomerase
- Helicase
- Primase
- Clamp Protein
- DNA Polymerase
- DNA Ligase
- Single-stranded Binding Proteins (SSB)
prevents DNA from supercoiling by introducing breaks to the
DNA to relieve stress
DNA Gyrase/Topoisomerase
‘unzips’ the double stranded DNA; breaks the hydrogen bonds between base pairs
Helicase
synthesizes primers which are short RNA sequences that bind to the parent DNA strand, serves as the jumping off paint for DNA polymerase
Primase
keeps DNA polymerase in place
Clamp Protein
synthesizes the new DNA strand
DNA Polymerase
T/F - DNA polymerase can only add nucleotides to an existing nucleotide chain and cannot initiate replication, hence the need for primers
T
joins the Okazaki fragments in the lagging strand
DNA Ligase
stabilizes/protects the single stranded region of
the DNA during replication
Single-stranded Binding Proteins (SSB)
short sections of DNA formed at the time of discontinuous synthesis of the lagging strand during replication of DNA
Okazaki fragments
DNA polymerase synthesizes the new strand by how?
adding nucleotides at the free 3’-hydroxyl group so that the new strand grows from 5’ to 3’.
In the leading strand replication is what?
continuous
In the lagging strand, which runs from 5’ to 3’, replication
In the lagging strand, which runs from 5’ to 3’, replication is?
discontinuous
T/F - Instead of one long strand of new DNA, the polymerase makes use of several primers to make fragments of the new DNA, called Okazaki fragments.
T