Structure of Nucleic Acidsand Genome Organization Flashcards
A hereditary disorder is characterized as inhibiting the ability of genes to be converted from DNA to RNA. Which step(s) of the central dogma is (are) being inhibited and how would this show in the individual’s phenotype?
The steps being inhibited are transcription (DNA->RNA) and translation (protein synthesis).
In transcription the RNA is synthesized via the use of DNA templates whereas in translation the mRNA is decoded to synthesize proteins.
If someone was unable to transcribe/translate their genetic code this would be a lethal condition whereby they would be unable to synthesize proteins.
What shoud one consider to be true regarding DNA according to Chargraff’s rules? What 3 processes depend on these rules?
- The amount of purines = the amount of pyrimidines
- The amount of Guanine = the amount of Cytosine
- The amount of Adenine = the amount of thymine
DNA replication, transcription, and translation
How does alkali compare heat regarding the effects each one has on DNA?
Alkali can be used to isolate RNA from DNA where as heat alone is able to convert dsDNA into ssDNA.
What does “Tm” signify? If some amount of DNA has a high Tm what do you know to be true about it?
Tm - denotes the temperature at which 50% of the dsDNA is separated
If a certain quantity of DNA has a high Tm one can deduce that it must also have a high GC content (guanine-cytosine)
By what mechanics do nucleases operate
Recognize and cleave phosphodiester bonds between nucleotides
In determining whether or not a virus is alive, one could think to what attributes?
- Can have both DNA and RNA
- Lack ability to replicate, transcribe, and translate genetic information
- Takes control of host reproductive machinery in order to reproduce
In the eukaryotic genome, histones combine DNA which forms one of two types of chromatin. What are the 2 types of chromatin?
- Euchromatin: Diffuse/loosely packed also transcriptionally active form
- Heterochromatin: Compact/tight also transcriptionally inactive form
In order to control transcription of the Eurkaryotic genome the nucleosome core is wrapped with 140bp of DNA forming a nucleosome. With the help of some linker DNA complexing with histone H1, many nucleosomes are able to be bound to one another.What shape does this make and what is the official name of this shape?
Forms a tubular coil known as a solenoid; can also be known as a 30nm fiber.
Enzymes and regualtors are attached to DNA in oder to perform what function?
Metabolism of nucleic acids
During what phase of mitosis is the chromosome visible?
Metaphase
In class we learned the locus of the CFTR gene to be 7q31.2- what does each number or letter signify?
Chromosome number (1-46)
Arm of chromosome (p or q)
Region
Band
.Sub-band
Alternative versions of the same gene are known as what?
Alleles
If you wish to make a karyotype of someone’s genetic information, one would require the use of colchicine. Colchicine is also approved to treat gout. How could this be? Explain the mechanism of colchicine that would justifies its useage in both of these scenarios.
Colchicine works to spontaneously (/nonspecifically) arrest cell proliferation in metaphase of mitosis. Hence, this allows for the viewing of condensed chromosomes in karyotyping as well as a drastic reduction in inflammation-inducing cells during the immune response to uric acid/crystal build up in Gout.
In comparing the ways RNA varies from DNA what could one list as some possible differences?
RNA is single stranded
Contains uracil in place of thymine
Ribose not deoxyribose
smaller than DNA
Which type of RNA serves as a template in translation?
mRNA
