V L3: DNA and Biological processing Flashcards
What is DNA replication?
semi-conservative
what forms a short RNA primer?
Specialised RNA polymerase known as primase
what is used to synthesis DNA?
DNA is synthesised using deoxynucleoside 5’-triphoshates (dNTPs).
what direction is DNA synthesised in ?
5’ — 3’
what is the replication fork?
region where the synthesis occurs
what are the 2 strands of DNA?
Leading and Landing
what is a mutation in DNA?
Mistakes occasionally occur during DNA replication
can you inherit a mutation in DNA?
Can only inherit a mutation if they are present in germ-line cells
what’s a germ line cell?
precursor cell that gives rise to gametes
whats a point mutation?
A alteration within a gene which involves a single base change
whats a silent point mutation?
same amino acid
whats a Missense mutation ?
changes one of the RNA codon sequences made during transcription. This different codon will then cause a different amino acid to be inserted into a protein during translation.
whats a Nonsense mutation ?
stops codon
whats a frame shift mutation?
altered reading frame
what used as genetic markers in forensic science?
In Forensic science we use these single nucleotide polymorphisms (SNPs) as genetic markers
what happens in s phase?
DNA replicates
what happens in G2 phase?
the cell undergoes cell division;
what happens in prophase?
condensed sister chromatids, forming of mitotic spindle.
what happen sin metaphase?
Nuclear envelope broken down. Alignment of chromosomes on equator of the spindle.
what happens in anaphase?
Separation of chromatids forming daughter chromosomes.
what happens in telophase?
Daughter chromosomes arrive at poles, nuclear envelope reassembles around each set of daughter chromosomes.
what happens in cytokinesis?
Cytoplasm divided into 2, producing 2 daughter cells
what is meiosis?
Specialised nuclear division producing haploid cells
meiosis is the production of?
gametes
what are the 2 cycles of cell division in meiosis?
Meiosis I and Meiosis II.
wat happens in meiosis I ?
maternal and paternal pair with each other (synapsis) to form a bivalent chromosome – recombination.
Then the maternal and paternal chromosomes pull apart to form daughter cells.
wat happens in meiosis II?
sister chromatids separate and are pulled to opposite poles, forming 4 haploid cells
what are the steps of DNA replication?
- Transcription 2.RNA processing
3. Translation 4.Replication
what is a gene?
unit of DNA that contains the information of a single polypeptide chain or a functional RNA (tRNA)
what does RNA polymerase do?
binds to a specific site on the DNA template and separates strands.
Bases in the template DNA base pair with incoming
________ _____
ribonucleoside triphosphates
what’s a non coding RNA molecule
A non-coding RNA (ncRNA) is an RNA molecule that is not translated into a protein.
whats the product of transcription?
primary RNA transcript
what happens to primary RNA transcript before its translated?
goes through processing in the nucleus
what happens to the primary RNA transcript before it goes through processing in the nucleus?
chemically modifying both ends of the mRNA
Capping the 5ʹ end
Polyadenylation of the 3ʹ end
what does RNA splicing remove?
introns
one pre-RNA can produce?
different proteins
whats leads to different proteins being synthesised from one primary mRNA molecule ?
Alternate or differential splicing
mature mRNA information is converted from what?
RNA to synthesise a protein
whats is the RNA sequence expressed as?
three nucleotide code – known as a codon
what do codons code for?
amino acid
stop in translation process
where does translation occur?
cell cytoplasm with the adapter molecule transfer RNA
one amino acid can be coded for by?
more than one mRNA codon.
How may possible codons does genetic code have?
64
How many codons can tRNA anti-coon recognise?
more than one
where is the ABO locus located?
located on chromosome 9
how big is the ABO locus?
18kb in size with 7 exons
DNA sequence of A and B alleles differ by …..
7 single nucleotide substitutions
which amino cid residue are important in determining the gene product is an A-transferase or B-transferase?.
position 266 and 268
