DNA Flashcards
What are nucleic acids?
Linear polymers of nucleotides
How many nucleotides are there?
5 A T G C and U
What structure does DNA adopt?
Complementary double helix -no 3D structure
What is the base sugar used in DNA? and RNA?
DNA uses deoxyribose and RNA uses ribose -the 2’H changes
What different types of bases are there?
2-purines (largest 2 cycles) and pyrimidines (smallest 1 cycle)
What is a nucleoside?
Its a nucleotide without a phosphate-just ribose and base
How is DNA organised when read? What is DNA primary sequence?
5’ to 3’, the other strand is going the other way (5’ end where 3’ end of the other)-the primary sequence is the sequence read 5’ to 3’
How are groups organised in the double helix?
they tun antiparallel, with the ribose sugars on the outside of the helix. The bases are flat and parrallel to one another. They have major and minor grooves
What kind of bonds libk the bases together?
Hydrogen bonds. 2 for A-T, 3 for C-G
What is the karyotype? Do E.coli have one? When can it been seen?
Karyotype is an ogrnaised profile of someones chrs (46). E coli only has 1 -no karyotype. Chr can be seen only during mitotic divison. during interphase, chr are less dense and cannot be seen
How is eukaryotic packaged?
Nucleosome-DNA around positive 8 histones that wrap DNA around it (2 turns)-also called beads on a string.
30nm fiber-Histones 1 sit between beads and pull DNA together.
Chromatin fiber-30nm chromatin is brought together again (700nm) and packed into chr