genetics chapter 7 Flashcards
adenine
1 NH3
guanine
2 H bonds, has an O double bond, 1 NH2
guanine formal name
deoxyguanosine 5”-monophosphate
thymine
1 bond H3C, 2 O double bond, 2H bonds
thymine formal name
deoxythymidine 5’-monophosphate
cytosine
1 NH3 bond, 2 H bonds, 1 O double bond
cytosine formal name
deoxycytidine 5’-monophospahte
pyrimadines
thymine and cytosine
-one single ring
purines
adenine and guanine
-two rings
what goes with A?
T
what goes with G?
C
coding strand and template strand
-coding strand is the exact same as the new strand thats being made (if its RNA that being made, then you switch the T for a U)
-template strand is made complementary
helicase, topoisomerase, primase, DNA polymerase 3, DNA Polymerase 1, then ligase
helicase, topoisomerase, primase, DNA polymerase 3, DNA Polymerase 1, then ligase
DNA Polymerase 1
removes and replaces DNA fragments in the LAGGING strand
DNA Polymerase 3
actually replicating the DNA
what is attached to the 3’ carbon
OH
what is attached to the 2’ in deoxyribose?
H
what is attached to the 2’ in ribose?
OH
what is attached to the 1’ ?
carbon
what is attached to the 5’?
1-3 phosphate groups
deoxynucleotide triphosphates
dTNPs,
- not part of polynucleotide chain
-act as substrates for DNA synthesis
deoxynucleotide MONOphosphates
-a part of polynucleotide chain
-have single phosphates called dNMPs (N refers to one of the 4 bases)
What is DNA polymerase (DNA pol)
by this, individual nucleotides are put into chains
what direction are chains built in?
5’ – 3’
what do we add groups onto?
the 3’ OH
What does DNA Polymerase do?
it catalyzes the formation of a phosphodiester bond between 3’ hydroxyl group of one nucleotide and 5’ phosphate group of next nucleotide
each polynucleotide chain has a _______________________
sugar phosphate backbone
what is the bases of nucleotide pairing?
- the bases of one strand are complementary to the bases in a corresponding strand
- The two strands are antiparallel, with respect to their 5’ and 3’ ends
- brings the partial charges into alignment
- charges would repel each other if the strands ran parallel
major and minor grooves
regions where DNA building proteins can make direct contact with nucleotides
what are the alternate forms of DNA?
B-form, A-from. Z-form
B-form
-most common form
-10.5 bases per turn
- bases perpendicular to long axis
A-form
-more compact
-11 bases per turn
-bases are not perpendicular
-found under dehydrating conditions
Z-form
-left-handed helix
-12 base pairs per turn
- zig-zag appearance
-physiology experience is unknown, but it is observed in certain sequences near the beginning of gene transcription
bacteria have how many origins of replication
one since it is circular
eukaryotic has how many origins of replication
multiple since it is linear
how many origins are in the human genome?
more than 10,000
what is replication best studies in?
bacteria
replisome
large complex of proteins at the origin of replication
what does the replisome do?
assembles at each replication fork on the DNA during synthesis
replication origins have ______ the attract _______ enzymes.
sequences; replication
consensus sequence
most common sequence/average
topoisomerase
unravels coil and then hooks back on
