DNA Flashcards
What are features of hereditary material
- Localized to the nucleus
- Present in stabel form in cells
- Contains information needed for structure, function, development, and reproduction of an organism
- replicate itself so that daughter cells contain same info as parent cells
- MUtable
How many strains of Pneumococcus did Griffith identify
2, R &S
Which strain of pneumococcus caused fatal pneumonia in mice
S
Waht will convert the R(rough) strain into S (smooth) strain
single nucleotide change
What happened to a mice infected with strain S
developed pneumonia and died
What happened to mice infected with strain R or heat strained S
they survived
What happened to the mice that died
the live type S bacteria were recovered
what happened when the scientist used heat-killed S bacteria and live R and infected mice
all aliquotes killed the mice except the one with DNA destroyed
what must phages do to reproduce
phages must infect bacterial host to reproduce
when does infection begin
when the phage injects DNA into the bacterial cell and leaves its protein shell on the surface
Phage protein assembled into the progney stage are released
by lysis of the host cell
where do phage DNA replicate in
bacterium
Content of sulfur and phosphorus in protein
protein contain large amount of sulfur but no phosphorus (NO P)
Content of sulfur and phosphorus in DNA
DNA has phosphorus but no sulfur
IS protein/DNA responsible for infecting bacteria
Phage DNA
In Hershey and chase experiment where was radioactivitty detected
empty phage particles (ghosts)
Describe arrangemeny of double helix
sugar phosphate backbones on outside, nucleotide bases arrayed in complementary pair towards the center.
what is a nucleotide consist of
- sugar
- nitrogenous base
- phosphate group
What is the sugar of DNA nucleotides
deoxyribose having 5 carbons
where is a nitrogenous base attached to in a nucleotide ?
1’ carbon
where is the hydroxyl group (OH) group attached to in a nucleotide
3’ carbon
what carbon is the free phosphate group attached to
5’ carbon
acronym of dNTPS
deoxynucleotide triphosphates (dNTPs)
what enzyme arranges individual nucleotide into chains
DNA polymerase
DNA polymerase catalyses the formation of which bond
phosphodiester bond
where is the phosphodiester bond found
3’ OH group of one nucleotide and 5’ phosphate group of another
This consists of alternating sugar and phosphate groups
sugar-phosphate backbone
what are the rules of base pairing
- base of one strand is complementary to the bases in the corresponding strand
- two strands are antiparrallel with respect to 5’ and 3’ ends
why do we pair bases
to form stable hydrogen bonds
how many hydrogen bonds exist between A and T
2 bonds
how many hydrogen bonds exist between G and C
3 bonds
the 3’end has an OH that can react with what to form a phosphodiester bond
react with phosphates on NTPs to form phosphodiester bond
single stranded DNA can serve as template for
replication and transcription
characteristics of DNA strand
denature and anneal
what is the interval of base pairs along DNA duplex
3.4 A
what form of DNA is the most common in living cells
B form
the grooves
are regions where DNA binding proteins can make direct contact with nucleotides
what is the diameter fo a DNA molecule
20 A
what is about each 360 degree turn take
10 base pair or 34A
