Functions And Dysfucntions Of Genomic Regulation DSA Flashcards
What does the central dogma of molecular biology explain?
The flow of genetic info from DNA to RNA to make a functional product,a protein
The central dogma state that the pattern of info that occurs most frequently in our cells is what?
From existing DNA to make new DNA (DNA replication)
From DNA to make new RNA (transcription)
From RNA to make new proteins (translation)
Describe the DNA backbone
Comprises of five C sugar (pentose) molecules bound to a nucleoside (A, C, G or T)
Pentose molecules are also asymmetrically joined to phosphate groups by phosphodiester bones
Phosphate-deoxyribose backbone
Which type of bond stabilizes and forms the double helix structure of DNA?
Hydrogen bonds between complementary nucleotides (G:C or A:T)
How many nucleotide pairs are there per helical turn?
10 nucleotide pairs per helical turn
What are the three forms of DNA?
B, A and Z form
Characteristics of the B form of DNA
10 nucleotide pairs per turn
Right handed
Characteristics of the A form of DNA
11 nucleotides per turn
Right handed
Characteristics of the Z form DNA
Left handed B form
Actively transcribed DNA
The deoxyribonucleotides of DNA are joined by what type of bond?
Covalent phosphodiester bond
Where do the phosphodiester bonds form?
Between the 3’-OH groups of the deoxyribose sugar on one nucleotide with the 5’-phosphate groups on the adjacent molecule
The 5’ end of one strand is base paired with the 3’ end of the other strand. What stabilizes this?
Noncovalent interactions - H bonds
How many hydrogen bonds are between adenine and thymine?
Two
How many hydrogen bonds are between guanine and cytosine?
Three
How does base pairing in the interior of the helix stabilize the interior of the double stranded DNA?
Because stacked bases repel each other due to their hydrophobic nature
What is chromatin?
DNA packaged into a protein-DNA structure which allows it to fit in the nucleus
Consists of very long double stranded DNA molecules, small basic proteins called histones as well as smaller amounts of non-histone proteins and a small quantity of RNA
What nucleosomes?
The fundamental organization upon which the higher order packing of chromatin is built
The core consists of a complex of 8 histone proteins with double stranded DNA wound around it
What are histones?
A heterogenous group of closely related arginine and lysine rich basic proteins which help them bind tightly to the negatively charged sugar phosphate backbone of DNA
Provide for the compaction of DNA
Each nucleosome core consists of what?
Two molecules each of histone H2A, H2B, H3 and H4
What separates each nucleosome?
Link histone H1
What are the three elements of chromosome structure?
Telomeres, centromeres and multiple origins of replication