Dna Stuffs

Question 1

Griffith

Answer 1

DNA v. Proteins
Bacteria that killed rats
R-strain in not deadly
S strain deadly
Heat killed s - mouse lives
Heat killed s+ live r= mouse dead

Only heat up to 60-65 protiens deconstruct and cell wall falls apart

R cells picks up dna from dead s strain and immediately divided so the new deadly bacs are made

DNA was the one responsible because the proteins were denatured

Question 2

Hershey and chase

Answer 2

1- P which labeled DNA
2- S which labeled protien

The phosphorus was with dead cells

The protien stayed in the solution at the top

Stop phase at manufacturing phase where you can clip off virus husk and see what molecule moved

Question 3

Nucleotide make up

Answer 3

Phosphorus (groups)
Pentosugar
Nitrogen base

Question 4

Pyramidines

Answer 4

C T U single ring

Question 5

Purines

Answer 5

AG double rings

Question 6

Label carbons

Answer 6

1 is far right
2 if has h instead of oh makes it deoxyribose
3 oh
4 branch
5 phosphorous group

Question 7

Bases with two hydrogen bonding

Answer 7

AT and U potentially

Question 8

Bases with three bonding sites

Answer 8

GC

Question 9

Chargrafs rule

Answer 9

15% Adanine 15% thiamine
35% G is 35% C

Question 10

Location of DNA

Answer 10

Eukaryotes - in nucleus (much more compacted)
Prokaryotes - in plasma in núcleo if

Question 11

Level 1 DNA compaction

Answer 11

DNA in double helix is wrapped around the histone

Question 12

Level 2 structure compaction

Answer 12

The Histones with dna wrap around to form nucleosomes which are coiled into chromatin fibers

Question 13

Level 3 dna structure compaction

Answer 13

Chromatin fibers wrap around more protien fibers

Question 14

Level 4 dna structure condensation

Answer 14

Chromatin are condensed and duplicated into a chromosome

Question 15

S phase

Answer 15

Where DNA is replicated into sister chromosomes

Question 16

Conservative replication

Answer 16

Parent strands stay together
And daughter strands pair up

Question 17

Semi conservative

Answer 17

One parent strand stays with daughter strand completely intact

Question 18

Dispersive

Answer 18

All 4 new strands are made with random parts of both the daughter and parent strand

Question 19

Meselson and stahl

Answer 19

Allow bacteria to grow in two types of nitrogen N15 and N14

Amount changes in set pattern
1st gen 100% in the center - which rules out conservative

2nd gen - had 50% in the middle and 50% on top which proved the semi conservative replication

Question 20

Where does replication start and dif of pro v eu

Answer 20

Origin of replication
Eukaryotes - have multiple organs
Prokaryotes - have 1

Eu have telomerase
Pro no

Question 21

Rules of dna replication

Answer 21

Read template 3- 5
Synthesis goes 5-3

Leading strand - one continuous fragment

Lagging strand- has multiple segments (Okazaki fragments)

Question 22

3 prime end

Answer 22

Oh group

Question 23

5 prime end

Answer 23

Phosphate group

Question 24

Helicase

Answer 24

Unwinds the dna

Question 25

Single strand binding protiens

Answer 25

Bound to unwound strand to keep them apart

Because of the hydrophobic nature of the inside of dna

Question 26

Topoisomerase

Answer 26

Goes in front of the helicase and relaxes the wind of the dna

Controles the stress

Question 27

Primase

Answer 27

Lays down 3-5 RNA nucleotides at the orgin

5-3

Question 28

DNA polymerase 3

Answer 28

Needs open 3prime end
Begins synthesis of new strand of dna starting from the primer lays 5-3

Question 29

DNA polymerase 1

Answer 29

Gets rid of primer RNA and replaces it with DNA but leaves a gap
Cannot creat phosphodiester bonds sugar backbone

Question 30

Ligase

Answer 30

Closes or minds the gap

Question 31

Telomere

Answer 31

Tip
Or Aglet
With repeated DNA pattern because of shrinking

Question 32

Telomerase

Answer 32

Occurs in cells that actively divide a lot ie dermal cells

Because of the gap that happens at the end of dna replication

Telomerase comes in and adds a whole chunk of the DNA telomere pattern to 3prime end to make it even longer

So that primase and polymerase and liGase can come in and add more to the short strand and extend side

Question 33

Proof reading

Answer 33

DNA polymerase 3 stops and goes back and fixes pair as it goes about synthesis

Question 34

Mis match repair

Answer 34

Past the point of proof reading
Nucleas comes in and clips out incorrect base and then poly 3 comes back to fix it

Proof reading + mix math = 99%

Question 35

Thymine dymers

Answer 35

UV causes horizontal intermolecular or covalent bonds instead of hydrogen bonds across or verticle

Question 36

Nucleotide excision repairs

Answer 36

Nucleare comes in and cuts out the thymine dymers but it has to cut a decently large chunk

And then poly 3 can come back and put in correct sequence

Question 37

Xeroderma pigmentosa

Answer 37

Person doesn’t have nuclease involved with Excision repairs so they are unable to rapair UV effected DNA which leads to high amounts of cancer and other skin damage

Question 38

Mutation

Answer 38

1% error
From repair processes

Question 39

Silent mutation

Answer 39

Change Doesn’t effect the amino acid that is coded

1 base is changed

Question 40

Missense mutation

Answer 40

Change of one base causes a change in the amino acid which does and doesn’t effect the protien ie cikle cell anemia

Question 41

Nonsense mutation

Answer 41

An accidental stop
When base change causes a stop amino acid to early in the sequence

Can cause protien to be too short which can effect folding and ultimately cause cell death

Question 42

Read through mutation

Answer 42

Stop codon does not appear and the amino acid chain just keeps reading which generally not bad but gives protiens tails

Most effective when deleted 1 to 2 but not 3 nucleotides

Question 43

Phase shift mutation

Answer 43

If a base is added or deleted then the three by threes will shift causing all the amino acids to be wrong after the mutation which causes a completely wrong protein to be made which would be catastrophic

Question 44

Codon

Answer 44

3 bases read at the same time that turns into one amino acid