DNA Flashcards
DNA stands for
deoxyribonucleic acid
Nucleotides are made up of
- a sugar called deoxyribose
-a phosphate group called Po-4
-and organic nitrogen base
DNA is
present in all living organisms
DNA controls
all the chemical changes within a cell.
The organic bases of DNA bases are
adenine
cytosine
thymine
guanine
ribose
Ribose is a sugar, like glucose, but with only five
carbon atoms in its molecule.
DNA gyrase
Is an enzyme relaxes the molecule ( uncoil)
DNA helicase
breaks the hydrogen bonds separates the two strands
RNA primase
single stranded it searches for a base code and adds an RNA primer.
DNA Polymerase lll
searches for and attaches at the RNA primer site once attached the DNA polymerase III begins adding free matching nucleotides to the original 3’ strand.
Complementary base pairing means that two bases are always each other’s pair.
true
The only way Watson and Crick’s model would work is if purines paired with other purines and pyrimidines were paired with other pyrimidines.
false
There are 8 organic base pairings for every complete 360 degree twist of the DNA molecule.
no there are 10
Rosalind Franklin and Maurice Wilkins used x-ray diffraction, where strands of DNA were bombarded with X-rays to yield a pattern on photographic film.
true
The nitrogenous base is attached to the 1’ carbon of the sugar by a glycosyl bond and the phosphate group is attached to the 5’ carbon by a phosphodiester bond.
true
the nitrogens are numbered
clockwise
In the carbon based deoxyribose sugar, the first four of the five carbon atoms, together with an oxygen atom, form the 5-membered ring. The fifth carbon sticks out from the ring.
true
replication can occur…
at different sites within one DNA molecule at the same time
enzymes are
proteins that perform a function
DNA HELICASE…
breaks the hydrogen bonds holding the strands together
what is the difference between dna and rna
dna is double stranded forming a double helix while rna is usually single stranded
DNA ligase
Seals the gap
DNA polymerase 1
replaces the rna primer with proper DNA. nucleotides
DNA Polymerase 2
proof reads the finished molecule; corrects mistakes
adding nucleotides goes
5’ to 3’
RNA is a
single chain
DNA has _______ sugar
deoxyribose
RNA has _______- sugar
ribose
RNA can be found in
nucelus and cytoplasm
DNA can be found in
the nucleus
are there different types of DNA
no
are there different types of RNA
MRNA
TRNA
rRNA
okazaki fragments are found on the
lagging strand
transcription occurs in
nucleus
translation occurs in a
ribosone
crispr allows scientists to
figure exactly where dna was cut
crispr Jean editing what is it
it allows scientists to make changes to DNA
how does crispr work
based on a bacterial immune system that allows a bacteria to fight an infection it uses an enzyme called CAS9
Franklin
disovered the structure of dna ( double helix)the famous photo is called “ photo 51”
chargaff
discovered the base pairing in DNA . he discovered the 4 niteogenous bases and declared the chargaff rules.
substitution
a mutation that exchanges one base for another
insertion
are mutations in which extra base pairs are inserted into a new place in the DNA
deletion
mutations in which a section of DNA is lost or deleted
Wilkins
he began the x ray diffracrion images of DNA that contributed to Watson and cricks discovery
frame shifts happen due to
deletion or insertion multiple bases are affected
point mutations
when only one nucleotide is altered the mutation if referred to as a point mutation
translocation mutations
if a longer sequence of nucleotides are changed, the mutation is referred to as a translocation mutations.
missense mutations
change a codon to one that encodes a different amino acid and cause a small change in the protein produced
silent mutations
change a codon to one that encodes the same amino acid and causes no change in the protein produced.
nonsense mutations
change a amino acid coding codon to a single “ stop” codons. and cause an incomplete protein. This can have serious affects since the incomplete protein probably wont function
causes of mutations
DNA fails to copy accurately
what is hemoglobin
Hemoglobin is a protein containing iron that facilitates the transport of oxygen in red blood cells
ssbs do what
hold strands of DNA apart
DNA Polyermase III
searches for and attaches at the primer site and then begins adding free matching nucelotides
RNA polymerase
