Chapter 11 Flashcards
nucleotides
building blocks of nucleic acids
ATP
nucleotide
purines
adenine, guanine
pyrimidines
cytosine, thymine, uracil
How are purines and pyrimidines attached to C1’ of the pentose?
by N-B-glycosyl bond
How are each nucleotide connected?
phosphodiester bond to the 3’
5’ end
free phosphate group
3’ end
free hydroxyl group
Chargaff’s Rule
number of purines always equals the number of pyrimidines
Adenine bonds with
Thymine
Guanine bonds with
Cytosine
DNA is a ________ double helix
right handed
two DNA strands are…
antiparallel
1 turn of a helix includes…
10 pairs
palindrome
sequence that reads forward and backwards the same way
Palindromes can produce…
cruciform structures in DNA
linear sequences of nucleotides in DNA encodes….
amino acid sequences of proteins
TAA
stop
supercoiling
intrinsic twisting of the double helix
-does not require DNA-protein interaction
nucleosomes
consists of eight protein molecules called histones of which DNA wraps around
double helix reversibly unwinds at temperature of…
60 degrees C
melting temperature of DNA (tm) depends on…
- temerature at which 50% is denatured
- G+C content
- different organisms
- pH
- salt conc.
deamination of nitrogenous bases
results in wrong base pairings and can lead to mutations
secondary structures of RNA
-hairpins, loops, bulge, double helix
restriction endonucleases (restrictases)
produced by specific bacterial cells and cut DNA at specific short sequences
DNA ligase
links DNA fragments together
DNA polymerase
synthesizes complementary strands on a single strand DNA template
-dedeoxy-nucleotides have no…
3’ hydroxyl which is needed to grow chain
