Nucleic Acids Flashcards
(18 cards)
How to proteins interact with DNA strands? Where? along the strand?
In the minor and major grooves.
What differs between the structure of DNA and RNA?
DNA does not have a hydroxyl group. This keeps it more stable.
Purines
A hetercyclic aromatic organic compound consisting of a pyrimidine ring fused to an imidazole ring (Adenine and Guanine).
Pyrimidines
Thiamine and Cytosine pair up with the purines Adenine and Guanine in DNA.
Helical structure of two strands of poly nucleotides arranged in an antiparallel fashion.
DNA!
What are the three types of mutations within sequencing that effect structure and function?
Substitutions
Insertions
Deletions
What happens when translating the RNA derived from a DNA suffers a frame shift mutation?
It alters every codon in mRNA following the mutation site and every protein produced to different.
Frameshift introduces premature stop codon.
What happens within DNA when uracil is noticed?
It flips uracil out of the double helix and BER (base excision repair) repairs it.
Describe the process and enzymes of BER (base excision repair).
DNA glycosylase removes damaged base, AP endonuclease cleaves the bond and DNA polymerase adds in the correct base. Again DNA polymerase puts the chain back together and DNA ligase attaches everything to form a correct chain.
Describe the process of mismatch repair
Endonuclease nicks the unmethylated daughter strand. Exonuclease digests the fragment. DNA polymerase and ligase fill the gap.
What area of DNA is most susceptible to UV damage and how is it repaired?
The flexible areas are the most susceptible and it is repaired with Nucleotide excision repair (NER).
How does ionising radiation work?
Causes double strand breaks and then the strands can be killed.
What is the difference between translation and transcription?
Translation is the synthesis of a protein from an mRNA template.
Transcription is the synthesis of RNA from a DNA template. The structure of DNA is not altered.
What is the differentiating step in RNA synthesis of prokaryotes and eukaryotes?
Eukaryotes go through a process of polyadenylation, or tailing which protect it out of the nucleus to wherever it is supposed to go.
Stem cells from adults are called:
‘induced pluripotent cells’
What is the only part of the nervous system that continues to grow nerve fibers as an adult?
Olfactory system.
Epigenetics
The study of mitotically and or meiotically heritable changes in gene function that cannot be explained by changes in DNA sequence.
What happens with DNA methylation?
Methyl marks added to certain DNA bases repress gene activity.
